Source: PENNSYLVANIA STATE UNIVERSITY submitted to
BIOLOGY AND EPIDEMIOLOGY OF PLANT PATHOGENIC AGENTS INFLUENCING HOST PLANT RESISTANCE, PATHOGEN VIRULENCE AND DISEASE MANAGEMENT.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0229626
Grant No.
(N/A)
Project No.
PEN04480
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jul 1, 2012
Project End Date
Jun 30, 2016
Grant Year
(N/A)
Project Director
Mcnellis, TI, W.
Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
208 MUELLER LABORATORY
UNIVERSITY PARK,PA 16802
Performing Department
Plant Pathology & Environmental Microbiology
Non Technical Summary
The Integrated Aerobiology Modeling System (IAMS), developed by Isard et al (2005), has been employed during the past 6 years to forecast the seasonal geographic spread of soybean rust (SBR) in North America. Estimates of savings to U.S. soybean growers that have resulted from activities associated with the soybean rust component of the PIPE vary greatly (e.g., Roberts et al 2006, Dorrance et al. 2007) and include a conservative calculation of approximately $200 million per year (Giesler and Hershman 2007). In anticipation of the possible incursion of new wheat stem rust races (Ug99) into North America and recent concern over the regional spread of southern corn rust, the IAMS has been expanded to forecast the aerial transport of these diseases in North America (Russo and Isard 2011, USDA 2011). Information on aphid transmission of soybean dwarf virus and adaptation to soybean crops will be useful in determining the risk of SbDV populations moving from widespread indigenous clover hosts into soybean crops on an epidemic scale. This information will be useful for disease risk analysis and development of epidemiological models of virus spread. Integration of host defense response in plants together with the use of environmentally friendly compounds represents the most sustainable method for controlling plant diseases rather than relying totally on fungicides. Information about the host defense response in perennial ryegrass would be useful in developing an integrated disease management strategy using novel compounds as well as compounds that are already known to elicit immune response in other plants. The epidemiological study of gray leaf spot of perennial ryegrass turf implies a deeper understanding of the relationship of environmental factors with gray leaf spot epidemics (Uddin et al. 2003). The results of the research will provide insights into disease forecasting model and integration of novel cultural practices, which will reduce the heavy reliance of fungicide application of gray leaf spot. Molecular tools are not currently widely used in the turfgrass industry. Therefore, the implementation of a molecular technique to accurately quantify dollar spot DNA and predict disease epidemics will provide turfgrass managers with a new resource to combat dollar spot, as more money is spent annually for the control of this disease on high input turfgrass than any other disease (Viji et al., 2004; Vargas, 1994). Additionally, use of molecular tools would aid in the practice of integrated pest management and to reduce the use of unnecessary fungicide applications.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
25%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121110110025%
2121549110210%
2121820110115%
2121820110210%
2121820117015%
2122130110225%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
2130 - Turf; 1110 - Apple; 1549 - Wheat, general/other; 1820 - Soybean;

Field Of Science
1101 - Virology; 1100 - Bacteriology; 1102 - Mycology; 1170 - Epidemiology;
Goals / Objectives
This project will utilize several different pathosystems for a variety of individual approaches to understand the biological impacts of host resistance genes, pathogen virulence genes, and insect vector genes regulating pathogen transmission on plant disease etiology. In addition, we will study the impacts of environmental parameters on pathogen survival and dispersal in the agricultural ecosystem. Although this project focuses on diverse pathosystems including bacterial, fungal, and viral pathogenic agents, the information gained in this project will be used to better understand each pathosystem in relation to disease causation and will provide needed information for designing more disease management strategies. The common threads of this project are better understanding of host responses to infection, gaining knowledge of host genetically determined defense strategies, identifying pathogen genetic variation associated with evolution of increased host range and virulence, and better understanding the role of environmental impacts on pathogen survival and spread. Knowledge gained can be used to develop more effective disease management utilizing sustainable and environmentally friendly strategies. Four pathosystems will be studied: 1. Erwinia amylovora causing fire blight of apple; 2. aerobiology of several invasive species including soybean rust; 3. luteoviruses in legume and cereal crops; and 4. gray leaf spot and dollar spot disease of turfgrasses.
Project Methods
1. For fire blight disease resistance studies bacteria will be mutagenized with a transposon. We then screen for mutations that disrupt the disease-causing ability of Erwinia amylovora. We inoculate the mutants onto apple fruits. Mutants that do not produce necrosis and bacterial ooze are selected for further analysis. The mutated gene is sequenced in the vicinity of the transposon-induced mutation and compared to the known genome sequence of E. amylovora. Normal copies of the gene are used to complement the mutant and restore virulence, confirming the involvement of the gene in fire blight disease. For apple tree genetics experiments, we analyze gene expression patterns at a global or whole-genome scale using DNA microarrays and large-scale RNA sequencing procedures. 2. The goal is to formulate empirical expressions to predict the escape fraction and the spore concentration at canopy height for wheat, soybean, and corn rust fungi. Lycopodium spores will be artificially released from point sources located inside the canopy at known rates. Field experiments will be used to calibrate numerical models of dispersion inside the canopy. The combination of experimental and numerical data will be used to develop an empirical model to predict escape fraction for each crop. This model will allow us to determine the concentration of spores above the field. A suite of numerical experiments using large eddy simulation (LES) models will be used to guide theoretical model development and validate theoretical results. 3. The consensus RNA sequence of a clover-infecting SbDV will be determined. The virus will then be inoculated to soybean using the clover aphid or the soybean aphid. The viral RNA sequence will be monitored at each of 10 serial transmissions. Transmission efficiency, time to symptom expression, symptom severity, and virus concentration will be determined at each transmission. Mutations consistently associated with host adaptations and aphid vectors will be identified. Levels of SbDV population diversity and mutation frequency will be determined through viral clones sequenced at the Penn State University genomic sequencing facility and using Bioedit (Ibis Theraputics, Carlsbad, CA) for sequence alignments. 4. Various concentration of exogenous salicylic acid (SA) and its analog benzothiadiazole (BTH) will be introduced into perennial ryegrass plants. Additionally, in a separate experiment, the effects of root treatment (soil drench) with SA and BTH on disease incidence and severity will be evaluated after challenging the plants with Magnaporthe oryzae. Seven days after inoculation, disease severity and incidence will be assessed. The correlation between induced resistance and activation of defense related genes, notably the expression profiles of PR-1, PR-2 and PR-5, will be investigated using quantitative RT-PCR following treatment with SA and BTH. The qRT-PCR and relative expression of these PR-genes will be normalized using perennial ryegrass eEF1A(s) and elf4A genes.

Progress 07/01/12 to 06/30/16

Outputs
Target Audience:The target audience for Dr. McNellis' program include apple and pear growers, the citrus industry, including citrus growers and processers, tomato growers, particularly in the northeast, and researchers on molecular microbiology of fire blight disease of apples and pears. Dr. McNellis' program interacts with these target audiences through peer-reviewed publications, grower newsletters, reports to sponsors, and presentations to growers. The target audiences for the outputs from the Isard program are Extension specialists, crop consultants, and field and specialty crop growers and agroindustry agents in the U.S who used the Integrated Pest Information Platform for Extension and Education (iPiPE) to assist with in-season management of pests on a large variety of crops. We have worked with growers, consultants and Extension professionals in iPiPE Crop-Pest program focused on alfalfa, apples, citrus, corn, cotton (2), hops, peanuts, small fruits, sorghum soybean (2), stone fruits, sunflower, sweet corn, tomatoes, tree fruits, vegetables (2) and wheat. The target audience of the work performed by the Rosa's group consisted of plant pathologists, college students, and other researchers on the Penn State campus and internationally. In fact, Rosa presented the results of her research at the annual meeting of the American Phytopathological Society in August of 2015 and her postdoc presented at the International Society-Molecular Plant-Microbe Interaction Congress in 2016. She also gave 4 lectures about her work to plant biology graduate students in the course PLBIO512 in 2014 and 2015 at Penn State and one seminar in the Penn State Plant Biology program in 2014 and ine in the Plant Science program in 2016. The target audience for Dr. Uddin's work is the Pennsylvania Turfgrass Industry that includes golf course industry, landscape, sod producers, and home owners. Dr. Uddin's research program focuses on innovative research on integrated management of turfgrass diseases employing induced systemic defense response in turfgrasses, population biology and epidemiology, chemical control, and turfgrass cultural management. Dr. Uddin research addresses the needs in the management of economically important diseases of turfgrass in Pennsylvania such as gray leaf spot, dollar spot, anthracnose basal rot, and Pythium foliar blight. The golf course industry ranks at the top among the clientele in the turfgrass industry in Pennsylvania in terms of research needs as golf turf is intensely managed with various fertility regimes, growth regulators and herbicides, and a number of cultural management practices that causes the turfgrasses to be prone to infection by various diseases. Currently, turfgrass diseases in golf courses are chiefly managed by fungicides. For environmental stewardship and reduction of chemical inputs and costs for disease management, integration of induced systemic resistance in a broader disease management spectrum is highly desirable. Dr. Uddin's disease research program has published 4 papers on induced systemic resistance in turfgrass disease management. The information generated from these publications will be integrated in to an integrated management strategy aiming at reduction of fungicide input in turfgrass system. Dr. Uddin's program presented information generated from the research to the industry clientele in conferences, trade shows, and workshops. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?McNellis' lab trained two Ph.D. students (Dr. Laura Ramos and Ms. Sara Klee) and two M.S. students (Ms. Xin Lin and Ms. Melissa Finley) during the reporting period. Dr. Ramos graduated with her Ph.D. degree in 2014, and Ms. Lin graduated with her M.S. degree in 2013. Ms. Klee and Ms. Finley are current students as of the conclusion of the reporting period. As part of the iPiPE CAP, Isard and his team supported and trained 42 undergraduate student summer interns from Cornell University, Iowa State University, North Dakota State University, Oregon State University, University of Florida, Utah State University, University of West Virginia , University of Missouri, University of California, Davis, University of Rhode Island, Montana State University, and Texas A&M University. The students were trained to (i) become familiar with the functionality of the iPiPE; (ii) identify in daily observations submitted by crop consultants and growers pests not endemic to a production region; (iii) detect errors in identification of endemic pest observations submitted; (iv) work with extension professionals to provide up-to-date pest management guidelines, commentary, and risk assessments. The Isard team built educational modules in the areas of IPM, food security, and IT technologies for the iPiPE student interns. Dr. Rosa is training two Ph.D. candidates in elucidating the interactions between toposviruses, tomatoes and thrips and one postdoctoral scholar and on Ph.D. candidate on the Ourmia melon virus interactions with its host plants. One of the two Ph.D. candidates is adding an environmental component to his project, to see how projected climate changes will influence the interactions in his study system. Rosa has also been training three undergraduate students enrolled in independent studies on two small projects and two high school students from the Penn State Upward Bound Math and Science Program. During this reporting period, Dr. Uddin has trained four Ph.D. students Yinfei Li, Alamgir Rahman, Brian Aynardi, and Gary Nolan. Yinfei Li and Alamgir Rahman graduated with their Ph.D. degrees in 2013 and 2014, respectively. Brian Aynardi has successfully defended his Ph.D. dissertation research and scheduled to graduate in December of 2016. Gary Nolan is currently a Ph.D. student as of the conclusion of the reporting period. How have the results been disseminated to communities of interest?Dr. McNellis' program has disseminated results in the form of seven peer-reviewed scientific publications. In addition, Dr. McNellis gave several presentations to grower groups and at national meetings on the research and applications of the results. In addition, Dr. McNellis' students gave presentations, including posters and oral presentations, at regional and national conferences. Dr. Isard's iPiPE CAP has been presented to stakeholders by the Extension Coordinators in their winter extension meetings for each of the 14 Crop-Pest Program during 2016. Isard has presented the iPiPE at numerous meetings and Congresses hosted by the American Phytopathology Society and Entomological Society of America over the past few years. The Rosa's group published seven journal papers to journals that have as audience virologists, plant pathologists, and biologists. These audiences represent the community interested in our findings. of her research at the annual meeting of the American Phytopathological Society in August of 2015. Her postdoc presented at the International Society-Molecular Plant-Microbe Interaction Congress in 2016. During this reporting period, Dr. Uddin's group published four papers in peer-reviewed journals on plant defense response, 34 reports in technical journal on chemical control of turfgrass diseases, and an industry workshop handbook on microscopy and diagnosis of turfgrass diseases. The information from the research results has been disseminated to research investigators in the area of induced systemic resistance in plants, the chemical industry that develops and distributes chemical and biological plant defense elicitors, and the turfgrass industry clientele. The information is disseminated through publication in journals, scientific conferences, industry conference and trade shows, industry workshops, University field-day events and seminars, and the field tours of industry-representative groups. During this reporting period, Dr. Uddin's chemical control research program delivered the Plant Disease Management Reports through the American Phytopathological Society annually. The reports for 2011-2016 are listed below. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2011. Fungicidal control of brown patch in a colonial bentgrass fairway, 2010. Plant Disease Management Reports 5:TO18. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2011. Evaluation of fungicides for dollar spot control on a creeping bentgrass fairway, 2010. Plant Disease Management Reports 5:TO15. Aynardi, B., Li, Y., Rahman, A., Uddin, W. 2011. Control of brown patch in a creeping bentgrass fairway, 2010. Plant Disease Management Reports 5:TO16. Aynardi, B., Li, Y., Rahman, A., Uddin, W. 2011. Evaluation of fungicides for dollar spot control on a mixed colonial bentgrass and annual bluegrass fairway, 2010. Plant Disease Management Reports 5:TO17. Aynardi, B., Li, Y., Rahman, A., Uddin, W. 2011. Management of anthracnose basal rot in a putting green with fungicides, 2010. Plant Disease Management Reports 5:TO19. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2011. Effect of fungicides on the severity of spring leaf spot/melting out in Kentucky bluegrass, 2010. Plant Disease Management Reports 5:TO14. Aynardi, B., Li, Y., Rahman, A., Uddin, W. 2011. Fungicidal Control of Pythium Foliar Blight in Perennial Ryegrass, 2010. Plant Disease Management Reports 5:TO04. Aynardi, B., Li, Y., Rahman, A., and Uddin, W. 2012. Evaluation of fungicides for control of Pythium foliar blight in perennial ryegrass, 2011. Plant Disease Management Reports 6: TO39. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2012. Curative effect of fungicides on gray leaf spot in a perennial ryegrass fairway, 2011. Plant Disease Management Reports 6: TO38. Aynardi, B., Li, Y., Rahman, A., and Uddin, W. 2012. Efficacy of fungicides in controlling anthracnose basal rot in a putting green, 2011. Plant Disease Management Reports 6: TO37. Aynardi, B., Li, Y., Rahman, A., and Uddin, W. 2012. Brown patch control in a colonial bentgrass fairway using fungicides, 2011. Plant Disease Management Reports 6: TO36. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2012. Fungicidal control of dollar spot in a creeping bentgrass/annual bluegrass fairway, 2011. Plant Disease Management Reports 6: TO35. Aynardi, B., Rahman, A., Li, Y., Uddin, W. 2012. Control of dollar spot on a mixed creeping bentgrass/annual bluegrass putting green, 2011. Plant Disease Management Reports 6: TO33. Aynardi, B. and W. Uddin. 2013. Control of Pythium foliar blight in perennial ryegrass using fungicides, 2012. Plant Disease Management Reports 7: T022. Aynardi, B. and W. Uddin. 2013. Chemical control anthracnose basal rot in mixed creeping bentgrass and annual bluegrass putting green, 2012. Plant Disease Management Reports 7: T021. Aynardi, B. and W. Uddin. 2013. Controlling brown patch on a colonial bentgrass fairway, 2012. Plant Disease Management Reports 7: T018. Aynardi, B. and W. Uddin. 2013. Fungicidal control of dollar spot on a putting green with a mixed stand of creeping bentgrass and annual bluegrass, 2012. Plant Disease Management Reports 7: T019. doi:10.1094/PDMR07. Aynardi, B. and W. Uddin. 2014. Control of anthracnose basal rot on a putting green, 2013. Plant Disease Management Reports 8: T018. Aynardi, B. and W. Uddin. 2014. Brown patch control using fungicides on a mixed colonial bentgrass and annual bluegrass fairway, 2013. Plant Disease Management Reports 8: T017. Aynardi, B. and W. Uddin. 2014. Control of dollar spot using fungicides at various rates and intervals on a fairway, 2013. Plant Disease Management Reports 8: T016. Aynardi, B. and W. Uddin. 2014. Dollar spot control on a putting green with fungicides, 2013. Plant Disease Management Reports 8: T015. Aynardi, B. and W. Uddin. 2014. Evaluation of compounds for the control of Pythium foliar blight, 2013. Plant Disease Management Reports 8: T014. Aynardi, B. and W. Uddin. 2015. Fungicidal control of dollar spot and brown patch on a mixed Penn A-4 creeping bentgrass and annual bluegrass putting green, 2014. Plant Disease Management Reports 9: T012. Aynardi, B. and W. Uddin. 2015.Dollar spot control on a fairway using commercially available fungicides, 2014. Plant Disease Management Reports 9: T011. Aynardi, B. and W. Uddin. 2015. Controlling dollar spot on fairway turf with fungicide tank-mixes and experimental products, 2014. Plant Disease Management Reports 9: T007. Aynardi, B. and W. Uddin. 2015. Control of anthracnose basal rot on a newly converted Poa annua putting green, 2014. Plant Disease Management Reports 9: T008. Aynardi, B. and W. Uddin. 2015. Control of brown patch on newly established colonial bentgrass, 2014. Plant Disease Management Reports 9: T009. Aynardi, B. and W. Uddin. 2015. Efficacy of fungicides in controlling Pythium foliar blight, 2014. Plant Disease Management Reports 9: T010. Aynardi, B. and W. Uddin. 2016. Control of dollar spot on an A-4 creeping bentgrass putting green, 2015. Plant Disease Management Reports 10: T028. Aynardi, B. and W. Uddin. 2016. Pythium foliar blight control with fungicidal compounds, 2015. Plant Disease Management Reports 10: T029. Aynardi, B. and W. Uddin. 2016. Control of dollar spot on an A-4 creeping bentgrass putting green, 2015. Plant Disease Management Reports 10: T031. Aynardi, B. and W. Uddin. 2016. Control of dollar spot on a creeping bentgrass and annual bluegrass fairway, 2015. Plant Disease Management Reports 10: T034. Aynardi, B. and W. Uddin. 2016. Brown patch control on a fairway with fungicides, 2015. Plant Disease Management Reports 10: T035. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? McNellis' lab has contributed to the understanding of plant antioxidant contributions to fire blight disease resistance, the role of gene regulators in the pathogenic activity of the fire blight bacterium Erwinia amylovora, the nature and limitations of trophic interactions of E. amylovora with host plants, and explored the potential biocontrol activities of E. amylovora strains for fire blight. Isard's program is funded through a $7 million, 5 year grant from the USDA AFRI Food Security Challenge Area Program in 2015 to expand the iPiPE to a large number of commodity/production regions throughout the U.S. Isard is the PD for the iPiPE CAP. The program was also supported by grants from the United Soybean Board, Peanut Board and industry as well. The iPiPE is an IT platform that currently supports 21 Crop-Pest Programs led by Extension professionals from universities across the nation. These programs engage growers, consultants and Extension professional to share data on pests and use derivative products created and distributed by iPiPE to assess the risk from pests on their farms and make informed management decisions. Dr. Rosa's lab group identified 13 aminoacids in the Ourmia melon virus (OuMV) movement protein (MP) that are either conserved among viral movement proteins in the 30k superfamily or that are hypothesized to be exposed and thus available for interactions. We were also able to identify a subset of these aminoacids necessary for viral systemic movement in Arabidopsis thaliana and in Nicotiana benthamiana. With the use of fluorescent tags and confocal microscopy, we confirmed that this subset of aminoacids is also necessary for tubule formation on protoplasts isolated from the plant species mentioned above. Moreover we showed that the OuMV MP co-localizes with the plant plasmodesmata at the plant cell wall. The results of this work have been submitted published MPP. In this time period our group also started investigations of insect and pathogen virulence and host resistance in another system, the one comprising tomatoes, tospoviruses and thrips vectors. At this regard we sequenced the first US isolate of Tomato spotted wilt virus and published an article in Archives of Virology. During this reporting period, Dr. Uddin's research team published four peer-reviewed journal articles that unraveled the innovative approach to integrated management of turfgrass diseases. These include application of epidemiological studies and employing induced systemic resistance in turfgrass pathosystem through induction of salicylic acid, silicon, semi-purified surfactin lipopeptides, and Bacillus amyloliquefaciens for control gray leaf spot of perennial ryegrass caused by the fungus Magnaporthe oryzae. The publications have added an important and sustainable component in the turfgrass disease management strategy used by the golf course superintendents. Significant reduction of disease severity and incidence by understanding the influence of certain important environmental parameters and application of these chemical and biological plant defense response elicitors will be significant in reduction of chemical use in disease management in turfgrass industry. Further, Dr. Uddin's team has published 34 reports in technical journal on chemical control of turfgrass diseases, an industry workshop handbook on microscopy and diagnosis of turfgrass diseases.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Tinsley, N.A., J.L. Spencer, R.E. Estes, K.A. Estes, A.L. Kaluf, S.A. Isard, E. Levine and M.E. Gray. 2016. Multi-Year Surveys Reveal Significant Decline in Western Corn Rootworm Densities in Illinois Soybean Fields. American Entomologist.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Bertran, M. Ciuffo, P. Margaria, C. Rosa, R. O. Resende, M. Turina. Host-specific accumulation and temperature effects on the generation of dimeric viral RNA species derived from the S-RNA of members of the Tospovirus genus. Journal of General Virology. dx.doi:10.1099/jgv.0.000598.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: K. Zhao, P. Margaria, C. Rosa. 2016. First report of the White clover mosaic virus and Turnip mosaic virus mixed infection on garlic mustard in Pennsylvania, United States. Plant Disease 100 (4): 866. http://dx.doi.org/10.1094/PDIS-09-15-1083-PDN.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: P. Margaria, C.T. Anderson, M. Turina, and C. Rosa. 2016. Identification of an ourmiavirus 30K movement protein amino acid residues involved in symptomatology, viral movement, subcellular localization and tubule formation. Molecular Plant Pathology. 17: 10631079 DOI: 10.1111/mpp.12348.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: P. Margaria, L. Miozzi, M. Ciuffo, C. Rosa, M.J. Axtell, H. Pappu and M. Turina. 2015. Small RNA profiles of wild-type and silencing suppressor-deficient tomato spotted wilt virus infected Nicotiana benthamiana. Virus Research 208 (2): 30-38. doi:org/10.1016/j.virusres.2015.05.021.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: P. Margaria, M. Ciuffo, C. Rosa and M. Turina. 2015. Evidence of a Tomato spotted wilt virus resistance-breaking strain originated through natural reassortment between two evolutionary-distinct isolates. Virus Research 196: 157-161. doi:10.1016/j.virusres.2014.11.012.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Li, Y, and Uddin, W. 2013. Effects of Relative Humidity on Infection, Colonization and Conidiation of Magnaporthe orzyae in Gray Leaf Spot Pathosystem. Plant Pathology 63:590-597.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Roossinck, M.J. 2016. Deep sequencing for discovery and evolutionary analysis of plant viruses. Virus Research invited review in press.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Stobbe, A., and M.J. Roossinck. 2016. Plant virus diversity and evolution. in Current Research Topics in Plant Virology, A. Wang, ed. pp. 197-215.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Roossinck, M.J. 2015. Move over bacteria! Viruses make their mark as mutualistic symbionts. J. Virol. invited JEMS article, 89:1-3.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Bao, X., and M. J. Roossinck. 2013. A Life History View of Mutualistic Viral Symbioses: Quantity or Quality for Cooperation? Curr. Op. Microbiol., 16:514-518.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Roossinck, M.J. 2013. Plant Virus Ecology. PLoS Pathogens 9(5): e1003304.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Bao, X., and M. J. Roossinck. 2013. Multiplexed interactions: viruses of endophytic fungi. Adv. in Virus Res. Adv. in Virus Res. 86:37-57.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Rodriguez, R.J., and M.J. Roossinck. 2012. Viruses, fungi and plants: Cross-Kingdom Communication and Mutualism. in Biocommunication of Fungi, pp. 219-227.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Roossinck, M. J. 2012. Persistent Plant Viruses: Molecular Hitchhikers or Epigenetic Elements? In Viruses: Essential Agents of Life. pp 177-186.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Roossinck, M. J. 2012. Plant virus metagenomics: Biodiversity and ecology. Ann. Rev. Genetics 46:357-367.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: M�rquez, L. M. and M. J. Roossinck. 2012. Do persistent viruses fit the trade-off hypothesis of virulence evolution? Curr. Op. Virol. 2:556-560.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Roossinck, M. J. 2012. Even viruses can be beneficial microbes. Microbiol. Australia 33: 111-112.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Roossinck, M. J. 2012. Viruses can be our friends. Microbiol. Today. 39:100-103.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Peyambari, M., M. K. Habibi, K-B. Fotouhifar, A. Dizadji, and M.J. Roossinck. 2014. Molecular characterization of a novel putative partitivurs infecting Cytospora sacchari, a plant pathogenic fungus. Plant Pathol. J. 30:151-158.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Xu, P., H. Wang, F. Coker, J.-Y. Ma, Y. Tang, M.E. Taylor and M. J. Roossinck. 2012. Genetic loci controlling lethal cell death in tomato caused by viral satellite RNA infection. Mol. Plant-Microbe Interact. 25:1034-1044.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Thapa, V. U. Melcher, G. B. Wiley, A. Doust, M. W. Palmer, K. Roewe, B. A. Roe, G. Shen, and M. J. Roossinck. 2012. Detection of Members of the Secoviridae in the Tallgrass Prairie Preserve, Osage County, Oklahoma USA Virus Res. 167:34-42.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Feldman, T.S., M.R. Morsy, and M. J. Roossinck. 2012. Are communities of microbial symbionts more diverse than communities of macrobial hosts? Fungal Biology 116: 465-477.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Stobbe, A.H., U. Melcher, M.W. Palmer, M. J. Roossinck, and G. Shen. 2012. Co-divergence and host-switching in the evolution of tobamoviruses. J. Gen. Virol. 93:408-418.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Min, B.-E., T.S. Feldman, A. Ali, G. Wiley, V. Muthukumar, B.A. Roe, M. J. Roossinck, U. Melcher, M. W. Palmer, R. S. Nelson. 2012. Cloning, ecological and epidemiological analysis of a novel tymovirus in Asclepias viridis from Oklahoma. Phytopathology 102:166-176.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Roossinck, M.J. 2016. Environmental Virology: How domestic viruses impact wild species. Curr. Op. Virol. In press.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Isard, S.A. and M. Chamecki. 2016. A physically-based theoretical model of spore deposition for predicting spread of plant diseases. Phytopathology106: 244-253.


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The target audiences for Dr. McNellis' work include apple and pear growers, the citrus industry, including citrus growers and processers, tomato growers, particularly in the northeast, and researchers on molecular microbiology of fire blight disease of apples and pears. Dr. McNellis' program works to develop novel biocontrol strategies for fire blight and other apple diseases, including the activation of plant defenses to promote resistance to fire blight. Bacterial diseases of tomatoes are becoming more prevalent in Pennsylvania recently, and Dr. McNellis' program is addressing this issue by initiating breeding programs for tomatoes resistant to bacterial canker disease. The tomato growing industry is interested in such varieties, since there are no commercially-available canker-resistant tomato varieties currently available. Work towards breeding of canker-resistant tomatoes has progressed during this reporting period. Dr. McNellis also published two papers on the microbiology of fire blight disease processes as well as a paper on apple tree molecular responses to fire blight infection during the reporting period, which are intended for researchers in the area of fire blight disease processes in apples. In addition, Dr. McNellis presented research on citrus greening-resistant grapefruit trees under development in his lab at the annual meeting of the American Phytopathological Society in Pasadena, CA, in August of 2015, which was intended for citrus disease resistance researchers and citrus production industry representatives. The target audiences for the outputs from the Isard program are Extension specialists, crop consultants, and field and specialty crop growers and agroindustry agents in the U.S., Canada and Mexico who used the Integrated Pest Information Platform for Extension and Education (iPiPE) to assist with in-season management of pests on a large variety of crops. In 2015, we engaged stakeholders associated with soybean, small fruits, tree fruits, tree fruits, wheat, alfalfa, and sorghum. The target audience of the work performed by the Rosa's group consisted of plant pathologists, college students, and other researchers on the Penn State campus and internationally. In fact, Rosa presented the results of her research at the annual meeting of the American Phytopathological Society in Pasadena, CA, in August of 2015, the main international plant pathology conference in the US. She also gave a lecture about her work to plant biology graduate students in the course PLBIO512 in December 2014 at Penn State and a seminar in the Penn State Plant Biology program also in December 2014. The target audiences for the work in the Roossinck lab are virologists working on populations dynamics of viruses, virus evolution, and plant virologists, as well as those interesting in applications of microbes that may be beneficial in plants. Dr. Roossinck presented eleven invited seminars on Virus Ecology and role of viruses in beneficial interactions at conferences and Universities during the reporting period. The target audience for Dr. Uddin's work is the Pennsylvania Turfgrass Industry that includes golf course industry, landscape, sod producers, and home owners. Dr. Uddin's research program focuses on innovative research on integrated management of turfgrass diseases employing induced systemic defense response in turfgrasses, population biology and epidemiology, chemical control, and turfgrass cultural management. Dr. Uddin research addresses the needs in the management of economically important diseases of turfgrass in Pennsylvania such as gray leaf spot, dollar spot, anthracnose basal rot, and Pythium foliar blight. The golf course industry ranks at the top among the clientele in the turfgrass industry in Pennsylvania in terms of research needs as the turfgrass in golf turf is intensely managed with various fertility regimes, growth regulators and herbicides, and a number of cultural management practices that causes the turfgrasses to be prone to infection by various diseases. Currently, turfgrass diseases in golf courses are chiefly managed by fungicides. For environmental stewardship and reduction of chemical inputs and costs for disease management, integration of induced systemic resistance in a broader disease management spectrum is highly desirable. Dr. Uddin's disease research program has published 3 papers on induced systemic resistance in turfgrass disease management. The information generated from these publications will be integrated in to an integrated management strategy aiming at reduction of fungicide input in turfgrass system. Dr. Uddin's program presented information generated from the research to the industry clientele in conferences, trade shows, and workshops. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During the reporting period, Dr. McNellis has continued training Ms. Sara Klee as a Ph.D. candidate student. Ms. Klee's research in the area of fire blight microbial genetics progressed well during the funding period, and included field observations of fire blight disease, testing of potential biocontrol bacterial strains on apple tree flowers, and genetic analysis of the fire blight pathogen, Erwinia amylovora. In addition, Ms. Melissa Finley joined Dr. McNellis' group. Ms. Finley has initiated a project that will provide information about how Erwinia amylovora obtains nutrition from the host tree, which could be useful for fire blight disease control. Finally, Mr. Jacob Smith completed his undergraduate independent study research on the tomato bacterial canker disease resistance genetic analysis, and he received training in plant biology, microbiology, and plant breeding in the process. Mr. Smith graduated with his B.S. degree in Biology in May, 2015, and subsequently took a summer job working on a plant pathology research farm project. As part of the iPiPE CAP, Isard and his team supported and trained 15 undergraduate student summer interns from Utah State University (3), University of West Virginia (2), University of Missouri (2), University of California, Davis (2), University of Rhode Island (4), Montana State University, and Texas A&M University. The students were trained to (i) become familiar with the functionality of the iPiPE; (ii) identify in daily observations submitted by crop consultants and growers pests not endemic to a production region; (iii) detect errors in identification of endemic pest observations submitted; (iv) work with extension professionals to provide up-to-date pest management guidelines, commentary, and risk assessments. The Isard team built educational modules in the areas of IPM, food security, and IT technologies for the iPiPE student interns. Rosa is training two Ph.D. candidates in elucidating the interactions between toposviruses, tomatoes and thrips and one postdoctoral scholar on the Ourmia melon virus interactions with its host plants. One of the two Ph.D. candidates is adding an environmental component to his project, to see how projected climate changes will influence the interactions in his study system. Rosa is also training two undergraduate students enrolled in independent studies on two small projects, the first to look at the use of biopesticides as viruscidal agents and the second to characterize the genetic components of cucumber mosaic virus isolates differing in host symptomatology. Dr. Roossinck continues to train Ms. Maliheh Safari as a PhD candidate. Ms Safari's research is in understanding the distribution and potential beneficial functions of persistent viruses in pepper. The lab also hosts Mr. Serge Oedragao, a visiting PhD student from the Univesity of Burkina Faso who is working continued understanding of factors involved in CMV evolution. In the fall of 2015 a new graduate student also joined the lab, Mr. Edelio Bázan, whose project is yet to be determined. Currently the lab is also hosting an honors Plant Sciences undergraduate student who will be doing an honors thesis in the lab on endophytes that may protect coffee from diseases. During this reporting period, Dr. Uddin has trained Alamgir Rahman, Brian Aynardi, and Gary Nolan as Ph.D. candidate students. Alamgir's research in the evaluation and characterization of systemic defense responses in perennial ryegrass following application of chemical and biological elicitors of plant defense against infection caused by the fungus M. oryzae, using various analytical, histological and molecular tools. The research training for Brian focuses on the molecular investigation of dollar spot pathogen Sclerotinia homoeocarpa, population biology of S. homoeocarpa from various climatic regions in the US, and quantification of the inoculum as a predictor for disease epidemic development. As a staff technician, Brian is also trained in development of fungicide evaluation experiments and various approaches to statistical analysis and data interpretation based on the objectives. Gary is trained for development and conducting research that encompasses the application of systemic plant defense response elicitors directly under various field conditions aiming at reduction of fungicide input and turfgrass growth and development that characterizes the turf quality suitable for various turf types, particularly the golf fairways and putting green. A Ph.D. degree was awarded to the candidate, Alamgir Rahman. How have the results been disseminated to communities of interest?Dr. McNellis' group published three papers in peer-reviewed journals during the reporting period. These are aimed at researchers in the area of plant-microbe interactions and also those studying apple tree resistance responses to fire blight disease. Results of the citrus greening resistance research were presented during the annual meeting of the American Phytopathological Society in Pasadena, CA, in August, 2015, in the form of a poster presentation. Former Ph.D. student Dr. Laura Ramos gave a talk at that same conference describing her results on fire blight microbiology, including the data from her two publications during the reporting period. These activities are all aimed to disseminate the findings of Dr. McNellis' group to the wider research community in fire blight, microbiology, and plant pathology in general. Dr. McNellis also submitted four quarterly reports to the citrus greening project sponsor describing progress towards development of citrus greening resistant grapefruit. Ms. Klee presented her results on fire blight genetics at several conferences, including the annual conference of the American Phytopathological Society in Pasadena, the Potomac chapter of the same society in March of 2015 in Rehoboth, Delaware, the Allegeheny division meeting of the American Society for Microbiology in November of 2014, and the Environmental Chemistry and Microbiology conference at Penn State in April of 2015. The iPiPE CAP has been presented to stakeholders by the Extension Coordinators in their winter extension meetings for each of the 7 Crop-Pest Program during 2015. Isard participated in a few of these extension meetings. In 2015, Isard presented posters on the iPiPE at the International IPM Symposium and APS national meeting and gave an invited presentation at the National IPM Coordinators Committee meeting. Isard is also the lead author on a manuscript describing the iPiPE CAP published in the Journal of IPM. The Rosa group submitted two journal papers (one published and one under review). We also published a manuscript in collaboration with international researchers. All these manuscripts were submitted to journals that have as audience virologists, plant pathologists, and biologists. These audiences represent the community interested in our findings. Rosa also presented her research at the American Phytopathological Society in Pasadena, CA, in August of 2015. During this reporting period, Dr. Uddin's group published three papers in peer-reviewed journals on plant defense response, six reports in technical journal on chemical control of turfgrass diseases, and an industry workshop handbook on microscopy and diagnosis of turfgrass diseases. The information from the research results has been disseminated to research investigators in the area of induced systemic resistance in plants, the chemical industry that develops and distributes chemical and biological plant defense elicitors, and the turfgrass industry clientele. The information is disseminated through publication in journals, scientific conferences, industry conference and trade shows, industry workshops, University filed-day events and seminars, and the field tours of industry-representative groups. Dr. Roossinck's group gave three research talks at the American Society for Virology conference in July of 2015, and Dr. Roossinck presented eleven talks in various venues on the research in the lab, with talks listed here: Plant Virus Ecology and Evolution: Pathogens to Mutualists", The Rob Goldbach Memorial Lecture, Wageningen, the Netherlands, November 2014. "What does virus ecology tell us about the evolution of plant and fungal viruses?", Society for General Microbiology, Birmingham, UK, March 2015. "The Role of the Viral Polymerase in Fidelity and Recombination", Association of Applied Biologists, Plant Virology Meeting, Birmingham, UK, April 2015. "Ecology of Plant and Fungal Viruses" University of Illinois, Champagne-Urbana, IL, April 2015. "Ecology and Evolution of Persistent Viruses of Plants and Fungi", Huck Symposium on Virus Evolution, State College, PA, April 2015. "Microbial Symbionts Help Plants Cope with Stress", Univerity of Missouri Symposium on Plant Stress, Columbus, MO, May 2015. "Virus Ecology from Pathogens to Mutualists", Gordon Research Conference on Microbial Population Genetics, Proctor Academy, NH, July 2015. "Viruses in Psuedogymnoascus destructans/White Nose Syndrome", Fish and Wildlife Conference on Control Measures for WNS, Grand Rapids, MI July 2015. "Beneficial viruses in plants:potential for crop improvement", Conference on Industrial Microbiology, Philadelphia, PA, August 2015. "Symbiosis: The Evolution of Cooperation Between Plants and Microbes" Swarthmore College, Swarthmore, PA, September 2015. What do you plan to do during the next reporting period to accomplish the goals?During the coming reporting period, Dr. McNellis' group plants to continue the development and testing of grapefruit potentially resistant to citrus greening. This will be done in collaboration with Dr. Timothy Gottwald at the USDA Horticultural Research Lab in Fort Pierce, FL. We anticipate at least the initial results to be obtained during the coming funding period. The sponsor also requested that we increase the scope of our resistant citrus development by incorporating citrus rootstocks and sweet orange into the project. We are now using similar techniques to develop citrus greening resistant sweet orange and citrus rootstock varieties, and this will continue during the coming reporting period. We will also continue our efforts to map the location of the tomato bacterial canker disease resistance locus using a recombinant inbred line set. This project will likely yield a preliminary genetic location for this important trait during the coming reporting period. Once the location is roughly identified, this will be of great use to molecular breeders for developing commercial tomato varieties resistant to bacterial canker disease. In addition, both graduate students (Klee and Finley) will continue their molecular analysis of Erwinia amylovora virulence and parasitism processes. We plan to submit one or more manuscripts describing these results to peer-reviewed journals during the coming reporting period. We will expand the iPiPE adding 7 new Crop-Pest Programs while continuing to engage more stakeholders to enter data and use the services provided by the existing CPPs. The 7 new CPPs will focus on citrus (FL), sunflower (ND), soybean (northcentral US), corn (South and Midwest), Cotton (CA), vegetables (NY), as well as small and stone fruits (OR). During the next reporting period, Rosa's group will continue to work on the tospovirus, ourmiavirus and cucumber mosaic virus systems. More specifically, we are identifying plant genes involved in the Ourmia melon virus (OuMV) movement. Together with our collaborators we are now investigating how movement proteins interact with plant cell wall components and our results should not only elucidate plant responses to viral infection, but also should also map processes in plant cell wall physiology. One of our goals it to resolve the structure of the OuMV movement protein to better predict the possible interactions between viral proteins and between viral and host proteins. This goal is pretty ambitious since no viral movement protein has been crystallized yet, but we will be able at least to purify the OuMV movement protein and to use it to proof its interactions with other viral or host components, such as proteins or nuclei acids. We will be also looking at the interactions between tospoviruses in plants doubly infected with tomato spotted wilt virus and impatiens necrotic spot virus. Lastly, we are planning to look at plant defense response regulation by tospoviruses and thrips under different light, temperature and draught stress conditions, and to perform field and controlled environment experiments to determine how environmental factors affect mutation rates in tospoviruses. Results from these studies will require few years, but will be used to improve management strategies to control the insurgence of resistant breaking strains of tospoviruses able to overcome natural plant resistance via mutation and recombination. During the coming period the Roossinck lab will continue our research on experimental evolution of CMV and related viruses. We are expanding our analyses of recombination to look at differences in different hosts. We have generated a number of new mutants with deoptimized codon usage and will moniter their evolution in rice and N. benthamiana. During the next reporting period, Dr. Uddin's team plans to continue the research on application of plant defense response elicitors. The further research on plant defense response will focus on application of the results obtained from the current basic research to various applied research experiments in the field. This will be aimed at the end-users in the industry for development of an integrated disease management strategy. The research will address the question pertaining to environmental stewardship, reduction of chemical inputs in turfgrass system, reduction of costs associated with disease management, and the turfgrass quality that is suitable for different turf types in fairways and putting greens. Additionally, Dr. Uddin's research team plans to continue the research on the molecular investigation of dollar spot pathogen, Sclerotinia homoeocarpa, population biology of S. homoeocarpa from various climatic regions in the US, and quantification of initial inoculum as a predictor for disease epidemic development.

Impacts
What was accomplished under these goals? During this reporting period, Dr. McNellis' group published three peer-reviewed journal articles that highlighted results with fire blight microbiology and genetics, and molecular responses of apple trees to fire blight infection. These articles will be of interest to the fire blight research community. In addition, Dr. McNellis' group has successfully propagated grapefruit plants that are potentially resistant to citrus greening disease, which is devastating the citrus industry in Florida. These plants are to be tested for resistance to citrus greening using natural infection processes in Florida. Dr. McNellis' group has also further analyzed genetic resistance to bacterial canker disease of tomato during the reporting period. The resistance appears to be heritable and quite robust, making this a good candidate trait to use to breed resistance in commercial tomato varieties. Genetic segregation of the resistance trait has been observed, and it appears to be controlled by a single, dominant gene, for the most part. We initiated a mapping procedure that should give us a genetic map position for the gene controlling resistance to bacterial canker of tomato in this tomato population. Isard's program was funded this year through a $7 million, 5 year grant from the USDA AFRI Food Security Challenge Area Program to expand the iPiPE to a large number of commodity/production regions throughout the U.S. Isard is the PD for the iPiPE CAP. The program was also supported by a grant from the United Soybean Board. Seven iPiPE Crop-Pest Programs were initiated in 2015: soybean (South and Northcentral states), small fruits (New England), tree fruits (WV, VA, MD & PA), tree fruits (UT), wheat (MT & ND), alfalfa (CA), and sorghum (TX). The iPiPE IT platform was operationalized, apps for uploading data were built and distributed. Stakeholders, Extension specialists and student interns in all 7 CPPs submitted pest observations to the iPiPE. Isard and co-PIs also published results from NSF-funded field measurement and modeling experiments to better understand the physical process that control the escape of spores from crop canopies. Rosa: Our group identified 13 amino acids in the Ourmia melon virus (OuMV) movement protein (MP) that are either conserved among viral movement proteins in the 30k superfamily or that are hypothesized to be exposed and thus available for interactions. We were also able to identify a subset of these aminoacids necessary for viral systemic movement in Arabidopsis thaliana and in Nicotiana benthamiana. With the use of fluorescent tags and confocal microscopy, we confirmed that this subset of aminoacids is also necessary for tubule formation on protoplasts isolated from the plant species mentioned above. Moreover we showed that the OuMV MP co-localizes with the plant plasmodesmata at the plant cell wall. The results of this work have been submitted for publication to MPP; our manuscript received favorable feedback and is now under final revision. In this time period our group also started investigations of insect and pathogen virulence and host resistance in another system, the one comprising tomatoes, tospoviruses and thrips vectors. At this regard we sequenced the first US isolate of Tomato spotted wilt virus and published an article in Archives of Virology. Dr. Roossinck's group published two basic research papers, one in experimental evolution of Cucumber mosaic virus, and one on the biodiversity of plant viruses in wild plants. These papers will be of significant interest to most researchers in the Plant Virology field. The CMV evolution paper demonstrates that fidelity and recombination are two distinct aspects of the viral polymerase, and important finding for understanding how the virus evolves. The lab continues to pursue research on CMV experimental evolution, as well as the diversity and evolution of plant and fungal persistent viruses. We have also continued our studies on the evolution of codon usage in viruses, and constraints on codons in different hosts. During this reporting period, Dr. Uddin's research team published three peer-reviewed journal articles that unraveled the innovative approach to integrated management of turfgrass diseases. These include employing systemic defense responses in perennial ryegrass through induction of salicylic acid-mediated defense response, silicon induced systemic resistance, and semi-purified surfactin lipopeptides and live cells of Bacillus amyloliquefaciens against infection of prrennial ryegrass caused by the fungus Magnaporthe oryzae. The publications have added an important and sustainable component in the turfgrass disease management strategy used by the golf course superintendents. Significant reduction of disease severity and incidence by application of these chemical and biological plant defense response elicitors will be pivotal in reduction of fungicide in disease management in turfgrass industry. Further, Dr. Uddin's team has published six reports in technical journal on chemical control of turfgrass diseases, an industry workshop handbook on microscopy and diagnosis of turfgrass diseases.

Publications

  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Ramos, L. S., Lehman, B. L., Peter, K. A., and McNellis, T. W. (2014) Mutation of the Erwinia amylovora argD gene causes arginine auxotrophy, nonpathogenicity in apples, and reduced virulence in pears. Applied and Environmental Microbiology 80:6739-6749.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Kaja, E., Szczesniak, M. W., Jensen, P. J., Axtell, M. J., McNellis, T. W., and Makalowska, I. (2015) Identification of apple miRNAs and their potential role in fire blight resistance. Tree Genetics & Genomes 11:812, DOI 10.1007/s11295-014-0812-3.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Ramos, L. S., Sinn, J. P., Lehman, B. L., Pfeufer, E. E., Peter, K. A., and McNellis, T. W. (2015). Erwinia amylovora pyrC mutant is virulent despite pyrimidine auxotrophy. Letters in Applied Microbiology 60:572-579.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Skarpaas, O., Jongejans, E., Ferrari, M. J., Long, E. S., Dauer, J. T., Schwarz, C. M., Rauschert, E. S. J., Jabbour, R., Mortensen, D. A., Isard, S. A., Lieb, D. A., Sezen, Z., Hulting, A. G., and Shea, K., (2014) A unified gravity approach to dispersal. Theoretical Ecology 8(2). DOI 10.1007/s12080-014-0245-5.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Sanatkar, M.R., Scoglio, C., Natarahan, B., Isard, S. A., and Garrett, K. A. (2015) History, epidemic evolution, and model burn-in for a network of annual invasion: soybean rust. Phytopathology 105: 947-955.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Pan, Y., Chamecki, M. , Isard, S. A. and Nepf, H. M.. (2015) Dispersion of particles released at the leading edge of a crop canopy. Agricultural and Forest Meteorology 211-212: 37-47.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Kelly, H. Y., Dufault, N. S., Walker, D. R., Isard, S. A., Schneider, R. W., Giesler, L. J., Wright, D. L., Marois, J. J., Hartman, G. L. (2015) From Select Agent to an Established Pathogen: The Response to Phakopsora pachyrhizi (Soybean Rust) in North America. Phytopathology 105 (7): 905-916.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Isard, S. A., Russo, J. M., Magarey, R. D., Golod, J., VanKirk, J. R. (2015) From Select Agent to an Established Pathogen: Integrated Pest Information Platform for Extension and Education (iPiPE): Progress Through Sharing. Journal of Integrated Pest Management 6(1): 15; DOI: 10.1093/jipm/pmv013.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2015 Citation: P. Margaria, L. Miozzi, M. Ciuffo, C. Rosa, M. J. Axtell, H. Pappu and M. Turina. 2015 Comparison of small RNA profiles in Nicotiana benthamiana and Solanum lycopersicum infected by polygonum ringspot tospovirus reveals host-specific responses to viral infection. Virus Research. Accepted September 25, 2015.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2015 Citation: P. Margaria and C. Rosa. 2015. First complete genome sequence of a tomato spotted wilt virus isolate from the United States and its relationship to other TSWV isolates of different geographic origin. Archives of Virology. DOI: 10.1007/s00705-015-2589-6 ARVI-D-15-00448.1.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Roossinck, M. J. Metagenomics of plant and fungal viruses reveals an abundance of persistent lifestyles. Frontiers in Microbiology 5:e787.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Roossinck, M.J. and F. Garc�a-Arenal. 2015. Ecosystem simplification, biodiversity loss and plant virus emergence. Curr. Op. Virology 10:56-62.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Roossinck M.J. 2015. A new look at plant viruses and their potential roles in crops. Mol. Plant Pathol. 16:331-333.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Roossinck, M.J., D.P. Martin and P. Roumagnac. 2015. Plant virus metagenomics: Applications for plant pathology. Phytopathology 105:716-727.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Roossinck, M.J. 2015. Plants, viruses and the environment: ecology and mutualism. Virology 60th Anniversary edition 479-480:271-277.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Pita, J. S., V. Morris, and M. J. Roossinck. 2015. Mutation and recombination frequencies reveal a biological contrast within strains of Cucumber mosaic virus. J. Virol. 89:6817-6823.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Thapa, V. D. J. McGlinn, U. Melcher, M. W. Palmer and M. J. Roossinck (2015). Determinants of taxonomic composition of plant viruses at the Nature Conservancy's Tallgrass Prairie Preserve, Oklahoma. Virus Evolution 1(1): vev007.
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2015 Citation: Roossinck, M.J. 2015. Evolution of persistent viruses in plants. in Virus Evolution. Weaver, Roossinck, Denison and Vignuzzi, editors, in press.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Rahman, A., Wallis, C. M. and Uddin, W. 2015. Silicon induced systemic defense responses in perennial ryegrass against infection by Magnaporthe oryzae. Phytopathology. 105:748-757.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Rahman, A., Uddin, W. and Nancy, W. 2015. Induced systemic resistance responses in perennial ryegrass against Magnaporthe oryzae elicited by semi-purified surfactin lipopeptides and live cells of Bacillus amyloliquefaciens. Mol. Plant Pathol. 16(6): 546-558.
  • Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Rahman, A. 2014.Evaluation and characterization of systemic defense responses in perennial ryegrass following application of chemical and biological elicitors of plant defense against infection caused by the fungus Magnaporthe oryzae. The Pennsylvania State University.


Progress 10/01/13 to 09/30/14

Outputs
Target Audience: The target audience for Dr. McNellis’ work is primarily other researchers on tree genetics and genomics, and the molecular genetics of the bacterium Erwinia amylovora, the fire blight pathogen. The research publication product of Dr. McNellis’ program during this reporting period are in peer-reviewed scientific journals that specialize in publishing research results in plant genetics and molecular plant pathology. However, Dr. McNellis also interacts with vegetable and tree fruit commodity representatives, and received funding from the Pennsylvania Vegetable Marketing and Research Program, the Citrus Advanced Technology Research and Development Foundation of Florida, and the State Horticultural Association of Pennsylvania during the reporting period. Both of these funding agencies represent grower groups and Dr. McNellis reports results to these grower representatives. Applied projects include the discovery of bacterial disease resistance traits in tomato, the development of citrus varieties potentially resistant to citrus greening disease, and the exploration of induced immunity in apple trees for improved disease control. The target audiences for the IT platforms and aerobiology model outputs from the Isard program are Extension specialists, crop consultants, and field and specialty crop growers in the U.S., Canada and Mexico who used the Integrated Pest Information Platform for Extension and Education (iPiPE) to assist with in-season management of pests on a large variety of crops. The target audiences for the work in the Roossinck lab are virologists working on populations dynamics of viruses, virus evolution, and plant virologists, as well as those interesting in applications of microbes that may be beneficial in plants. Dr. Gildow’s program has nothing to report. The target audience of Dr. Uddin's research program is the turfgrass industry. Dr. Uddin provides strong support to the Turfgrass industry in management of turfgrass disease through IPM approach, including induced resistance in plants, disease forecasting, cultural management practices, and chemical control a components of the integrated management strategy. The novel approach of induced resistance in Dr. Uddin's program has delivered important information to the industry clientele on application of the concept in disease management. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? In Dr. McNellis’ program, one graduate student (Ms. Laura Ramos) successfully defended her thesis during the reporting period. Her project was on the topic of Erwinia amylovora virulence genes and the identification of novel virulence mechanisms in this pathogenic bacterium. She has recieved extensive training in basic molecular biology, microbiology, and genetics during the present reporting period, and she also got experience reporting her results and writing the results for publication in peer-reviewed journals. A second graduate student, Ms. Sara Atyeo, joined Dr. McNellis’ group in September of 2013, and she is carrying on the molecular genetics analysis of Erwinia amylovora, recieving training in molecular biology, genetics, plant biology, and molecular microbiology and plant pathology. Her work includes both lab and field work, with the field work occurring at the Penn State Fruit Research and Extension Center in Biglerville, PA. This represents a broad project with a range of objectives, including genetics of bacteria, tree physiology and symptom evaluation in the orchard, and cell biology, including tagging of bacteria with fluorescent proteins for tracking and observation when they are growing and moving in the plant. One student in the Isard program (Ying Pan) earned her Ph.D. in 2014. She is continuing to work in the program as a post-doc. The Isard program also has a Ph.D. candidate graduate student (Steve Conway). The Roossinck program is supporting a graduate student on this project, Ms Maliheh Safari, a Research Associate, Dr. Justin Pita, and two visiting scientists: Dr. Mikyeong Kim from S. Korea, and Dr. Tomofumi Mochizuki from Japan. In Dr. Uddin's program, a graduate student (Alamgir Rahman) successfully completed his graduate study the reporting period. His graduate research project was identifying the biological and chemical systemic resistance inducers, their mechanism of induction, and management of diseases through application of the concept of induced systemic resistance. He has received extensive training in basic in turfgrass disease defense response and biology of the pathogen, and he also gained experience in writing reports and publishing in peer-reviewed journals. Currently there are two graduate students in Dr. Uddin's program (Brain Aynardi and Gary Nolan) investigation population biology of dollar spot pathogen, Sclerotinia homoeocarpa, and application of induced systemic resistance in turfgrass health management and plant growth/development, respectively. How have the results been disseminated to communities of interest? Dr. McNellis’ group has primarily disseminated the results of their work through peer-reviewed publications in reputable journals that are read by molecular microbiologists and plant pathologists and plant geneticists. The publication in BMC Genomics is targeted towards researchers studying genomics in general, but is most likely to be read by those studying tree genetics. In addition, Dr. McNellis’ group provided a report to the Pennsylvania Vegetable Marketing and Research Program sponsor, which as published on their organization’s web site and was written to be understood easily by an educated non-scientist. Dr. Isard's team has disseminated the results of their field work through peer-reviewed journals that are read by meteorologists, engineers and agricultural scientists. The past success of the national soybean rust team in which Isard participated was chronicled in Plant Disease in a recent publication entitled "A coordinated effort to manage soybean rust in North America: a success story in soybean disease monitoring. The work from the Roossinck lab has been disseminated by peer-reviewed publications and by a number of invited talks given by Dr. Roossinck, listed here: Competition versus Symbiosis: Viruses as Models for New Evolutionary Paradigms" EMBL annual PhD Symposium, Heidelberg, November 2013 "How Microbes Can Help Feed the World",Undergraduate Research Symposium, University of Western Alabama, March 2014 "Ecology of Plant and Fungal VIruses:Viruses as the Good Guys", Bucknell University, March 2014 "Viruses and Plant Adaptation to Extreme Environments", CIRAD, Montpellier, France, April 2014 "Spillover of Agricultural Viruses into Wildland Plants", Institut Pasteur, Paris, France, April 2014 "Viruses and Plant Adaptation to Extreme Environments", Institut Jacques-Modod, Paris, France, April 2014 "Viruses and Plant Adaptation to Extreme Environments", Graduate student invited speaker, Washington State University, Pullman, Washington, April 2014 "Spillover of Agricultural Viruses into Wildland Plants", American Society for Virology Plant Virology Club Symposium, Fort Collins, Colorado, June 2014 "Persistant Viruses in Plants and Fungi:Molecular Fossils?", DNA Habitats and its RNA Inhabitants, Salzburg, Austria, July 2014 Dr. Uddin’ team has disseminated the results of their work through publications in peer-reviewed journals, non-refereed technical journals, trade journals, and extension/outreach publication. Additionally, Dr. Uddin's team has delivered the information to the industry through presentations in scientific conferences, industry conferences and trade shows, and workshops. What do you plan to do during the next reporting period to accomplish the goals? During the next reporting period, Dr. McNellis’ group plans to test the new grapefruit varieties for enhanced disease resistance and specifically for increased resistance to the citrus greening pathogen Candidatus Liberibacter asiaticus, in collaboration with labs at the USDA ARS Horticultural Laboratory in Ft. Pierce, Florida. Dr. McNellis’ lab will continue to analyze tomato accessions and breeding populations for resistance to bacterial diseases, including bacterial canker and bacterial speck disease, which are growing problems for the Pennsylvania vegetable grower community. In addition, Dr. McNellis’ program will continue to study Erwinia amylovora genetics related to fire blight disease and disease mechanisms. In particular, several novel virulence genes will be tested and analyzed to determine their functions in the virulence process, and also Erwinia amylovora bacteria tagged with fluorescent markers will be observed moving through plant tissues in an effort to better understand systemic movement mechanisms of these bacteria. As PD on the iPiPE CAP, Isard and his team will work in 2015 to expand the iPiPE to 8 new commodity/production areas (corn/MidWest & Southeast, small fruits/New England, Alfalfa/CA & AZ, tree fruits/WV, PA, VA, MD, tree fruits/UT, soybean/MO & AR, sorghum/TX & LA, and wheat/ MT, CO, ID, KS, ND, NE, SD, WA, WY). The Roossinck lab will continue studies in virus evolution using CMV as a model system. In particular we are interested in understanding how different related viruses can have dramatically different evolutionary trajectories. During the next reporting period, Dr. Uddin's team plans to investigate the diversity in pathogen population distribution in dollar spot pathosystem, representing various geographic regions of the United States, and the pathogen's host adaptation for cool season and warm season turfgrass species. Additionally, Dr. Uddins team will continue to investigate the application of systemic plant defense inducers aiming at reduction of chemical inputs in turfgrass management, and enhance turfgrass growth and development that will have direct impact on turf quality and environmental stewardship in the golf courses.

Impacts
What was accomplished under these goals? During the present reporting period, Dr. McNellis program has identified genetic loci controlling powdery mildew resistance and resistance to woolly apple aphid using gene expression profiling of genetically segregating populations of apple trees. This represents a significant and useful advance in the use of gene expression profiling and genomics analysis for identification of useful traits in tree populations, and will aid in the development of disease-resistant rootstock and fruiting varieties of apple. Furthermore, Dr. McNellis’ group has identified a series of genes in Erwinia amylovora that are required for the bacteria to cause disease and grow in apple and pear trees and fruits. This further develops the basic understanding of the mechanisms of fire blight disease development. Dr. McNellis’ group has also developed several new varieties of “Duncan” grapefruit that have promise to be resistant or at least less susceptible to citrus greening disease. These plantlets were developed during the present reporting period, which was a time-consuming process due to the slow growth and generation time of citrus. However, this is a significant accomplishment during the present reporting period that will set up Dr. McNellis’ program to test the new varieties for resistance to citrus greening, which is done in collaboration with groups at the USDA ARS in Ft. Pierce, Florida. In addition, the new citrus varieties are being tested for increased expression of disease resistance characteristics, which would be indicators of resistance to the citrus greening disease. Since citrus greening is such a problematic disease for Florida citrus growers, and new disease-resistant grapefruit varieties would be of great interest to these groups. Isard's program with funding from an NSF grant has published the results of field measurement and modeling experiments to better understand the physical process that control the escape of spores from crop canopies. The new mathematical formulations have been incorporated into predictive aerobiology models that are operated as part of the iPiPE. The program expanded the iPiPE in 2014 with United Soybean Board, Peanut Board and industry funding to include soybean, corn, citrus and peanut growers. As a result of this groundwork, Isard and colleagues were recently awarded $7 million by USDA AFRI Food Security Challenge Area Program to expand the iPiPE to a large number of commodity/production regions throughout the U.S. Isard is the Project Director on the NIFA Cooperative Agricultural Project. The Roossinck lab completed an extensive study in Cucumber mosaic virus (CMV) recombination showing that different strains have dramatically different frequencies of recombination and that these map to the viral polymerase. The manuscript for this study is under preparation. The lab also initiated two aspects of these goals: one on how codon usage affects the evolution of CMV; and one on how viral quasispecies are formed and maintained, using CMV and its satellite RNAs. In the present reporting period, Dr. Uddin's program has identified important induced systemic resistance mechanism in perennial ryegrass plants as part of an IPM approach to management of gray leaf spot of perennial ryegrass turf. Additionally, Dr. Uddin's program delivered information on epidemiology of turfgrass diseases as components of integrated disease management strategy to the clientele in the industry. Turf managers will be able to utilize the information generated from the research on induced systemic resistance in conjunction with epidemiological studies such as influence of environmental conditions on disease development and disease forecasting. This integrated management strategy will effectively reduce chemical input steering toward environmental stewardship.

Publications

  • Type: Other Status: Published Year Published: 2014 Citation: Jensen, P.J., Fazio, G., Altman, N., and McNellis, T.W. (2014) Maping in an apple (Malus x domestica) F1 segregating population based on physical clustering of differentially expressed genes. BMC Genomics 15:261. http://www.biomedcentral.com/1471-2164/15/261
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Pan, Y., M. Chamecki, and S.A. Isard, 2014. Large-eddy simulation of spore dispersion inside the canopy roughtness sublayer, Journal of Fluid Mechanics 753: 499-534.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Gleicher, S.C.., M. Chamecki, S.A. Isard, Y. Pan, and G.G. Katul, 2014. Interpreting three-dimensional spore concentration measurements and escape fraction in a crop canopy using a coupled Eulerian-Lagrangian stochastic model, Agricultural and Forest Meteorology 194: 118131.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Sikora, E. J., Allen, T. W., Wise, K. A., Baniecki, J., Bergstrom, G., Bradley, C., Brown-Rytlewski, D., Chilvers, M., Coker, C., Damicone, J., DeWolf, E., Dorrance, A., Dufault, N., Esker, P., Faske, T., Giesler, L., Grau, C., Golod, J., Grybauskus, A., Franc, G., Hammerschmidt, R., Hartman, G., Henn, A., Hershman, D., Hollier, C., Isakeit, T., Isard, S., Jacobson, B., Jardine, D., Kemerait, B., Koenning, S., Malvick, D., Markell, S., Marois, J., Monfort, S., Mueller, D., Mueller, J., Mulrooney, B., Newman, M., Osborne, L., Padgett, G.B., Ruden, B., Rupe, J., Schneider, R., Schwartz, H. Shaner, G., Singh, S., Stromberg, E., Sweets, L., Tenuta, A., Trippett, C., Vaiciunas, S., Yang, X.B., Zidek, J., 2014. A coordinated effort to manage soybean rust in North America: a success story in soybean disease monitoring. Plant Disease 98: 864-875.
  • Type: Book Chapters Status: Published Year Published: 2013 Citation: Luck, J., Campbell, I., Magarey, R., Isard, S., Aurambout, J-P., Finlay, K. 2013. Climate change and plant biosecurityImplications for policy. Plant Biosecurity Handbook. In Principles and Practices for the Identification, Containment and Control of Organisms that Threaten Agriculture and the Environment Globally. Gordh, G; McKirdy, S. (Eds.) Springer, NY. 760 p.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Neufeld, K.N., S.A. Isard, and P.S. Ojiambo, 2013. Quantifying the relationship between disease severity and concentration and escape of Pseudoperonospora cubensis sporangia from a cucumber canopy. Plant Pathology 62. 1366-1377.
  • Type: Other Status: Published Year Published: 2014 Citation: Du, Z., A. Chen, W. Chen, Q. Liao, H. Zhang, Y. Bao, M.J. Roossinck, and J.P. Carr. 2014. Nuclearcytoplasmic partitioning of Cucumber mosaic virus protein 2b determines the balance between its roles as a virulence determinant and an RNA-silencing suppressor. J. Virol. 88:5228-5241
  • Type: Other Status: Published Year Published: 2013 Citation: MacDiarmid, R., B. Rodoni, U. Melcher, F. Ochoa-Corona, and M.J. Roossinck. 2013. Biosecurity implications of new technology in plant virus research. PLoS Pathogens 9:8
  • Type: Other Status: Published Year Published: 2014 Citation: Stobbe, A.H. and M.J. Roossinck. 2014. Plant Virus Metagenomics: what we know and why we need to know more. Frontiers in Plant Science 5:e150
  • Type: Other Status: Published Year Published: 2014 Citation: Safari, M. and M. J. Roossinck. 2014. How does the genome structure and lifestyle of a virus affect its population variation? Curr. Op Virology 9:39-44
  • Type: Other Status: Published Year Published: 2014 Citation: Rahman, R., Kuldau, G. A., and Uddin, W. 2014. Induction of salicylic acid-mediated defense response in perennial ryegrass against infection by Magnaporthe oryzae. Phytopathology 104:614-623


Progress 10/01/12 to 09/30/13

Outputs
Target Audience: For Dr. McNellis’ program, the target audience includes molecular plant pathologists studying bacterial interactions with plants, particularly related to fire blight disease. For Dr. Isard's program, the target audiences for the aerobiology model outputs are Extension specialists, crop consultants, and soybean, wheat, and corn growers in the U.S., Canada and Mexico who used the ipmPIPE/iPiPE IT platforms to assist with in-season management of pests on soybean and cereal crops. For the Roossinck program, the target audience includes those interested in virology, plant virology and virus evolution. For Dr. Uddin's program, the target audience for the epidemiology and management of turfgrass diseases will be turf managers in golf course industry, landscapes, sports fields, home lawns, and business parks. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? In the McNellis lab program, three Ph.D. degree candidate graduate students are receiving training in the areas of plant molecular pathology, plant microbiology, and plant genetics of disease resistance. The graduate student projects include analysis of further novel genes required for the fire blight disease process as well as analyzing and mapping genes in tomato that contribute to quantitative disease resistance traits. In the Isard program 1 Ph.D. degree candidate graduate student and 1 M.S. student participated in the measurement and modeling experiments. The M.S. student graduated in May and is currently employed in industry as a dispersion modeler. The Roossinck lab supports training of two undergraduate students, one graduate student, and two postdocs who are working in the areas of experimental viral evolution and the analysis of viral populations. In Uddin's program, 3 Ph.D. students are receiving training in the area of epidemiology and management of turfgrass diseases. The Ph.D students projects include epidemiology of turfgrass diseases of the pathogens, and physiological stress responses in turgrasses to chemical inducers for development of systemic resistance in turfgrasses, management of turfgrass diseases through induction of plant disease response, population biology of turfgrass pathogens, and an innovative approach to disease forecasting through molecular detection of pathogen population/inoculum in rhizosphere. How have the results been disseminated to communities of interest? The McNellis program published the results regarding the discovery of a new gene that is an essential regulator of Erwinia amylovora virulence in apple trees in the peer-reviewed journal Molecular Plant Pathology, and published the findings about the role of the Fibrillin4 gene in apple tree disease and oxidative stress tolerance in the peer-reviewed journal PLoS One. The results of the research conducted by the Isard lab have been disseminated to the epidemiology research community in the peer-reviewed journal, Plant Pathology. Two additional manuscripts are in preparation and will target the meteorological research community. The Roossinck lab published two papers in the Journal of Virology, presented a talk on this topic at the American Society for Virology annual meeting, and the PI presented several invited talks/seminars that included results from this project. The Uddin's labs have distributed the information to the communities of interests that are primarily turfgrass industry. The information was disseminated to the industry clientele through commodity industry speaking engagements in extension meetings and conferences, publications in industry journals, and non-refereed technical journals. Additionally, Uddin's lab published an epidemiological paper in peer reviewed journal that is currently in press What do you plan to do during the next reporting period to accomplish the goals? The McNellis program will continue to identify novel virulence genes in the fire blight pathogen Erwinia amylovora and will characterize the mechanisms of their roles in the fire blight disease process, including the possible role for quorum sensing bacterial communication in the fire blight disease process. In addition, the McNellis program will continue to identify genes whose expression levels are correlated with apple tree traits, including resistance to fire blight, and use them for DNA molecular marker development for important apple traits. The Isard program will continue to study the movement of airborne pathogens at field and landscape scales incorporating results into operational aerobiology models. We are also building a new, more advanced Information Technology platform (iPiPE) for disseminatingaerobiological forecasts of plant diseases, associated assessments of risk of crop losses, and pest management guidelines. The goal is to sustain the new platform with support from industry. The Roossinck group will continue studies in experimental evolution, now focusing on the populations dynamics during the establishment of a quasispecies, and on the rates and viral control of recombination events. Dr. Uddin's program will continue to identify major environmental factors that influence development of turfgrass disease epidemics, the mechanisms of induced systemic resistance in perennial ryegrass in gray leaf spot pathosystem, physiological stress responses in turgrasses to chemical inducers for development of systemic resistance in turfgrasses, population biology of turfgrass pathogens, and disease forecasting through employing methods in molecular detection of pathogen population/inoculum in rhizosphere.

Impacts
What was accomplished under these goals? The McNellis lab program identified a new gene that is an essential regulator of Erwinia amylovora virulence in apple, and discovered that the apple tree Fibrillin4 gene is required for oxidative stress tolerance and fire blight disease tolerance in apple trees. Isard's program conducted field measurement and modeling experiments that led to better understanding of the physical process that control the escape of spores from crop canopies. The new mathematical formulations are being incorporated into predictive aerobiology models that are operated as part of the ipmPIPE/iPiPE. The Roossinck lab was able to map the viral genetic components involved in modulating mutation frequencies and fixation of variants in a population. Dr. Uddin's program determined that relative humidity is a major factor influencing the development of gray leaf spot epidemic in perennial ryegrass turf. The research has identified the range of percent relative humidity that induces spore production and its influence on infection. A minimum of 88% relative humidity is required for infection of perennial ryegrass by Magnaporthe oryzae at 28 C, the most favorable temperature for disease development.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Ramos, L.S., Lehman, B.L., Sinn, J.P., Pfeufer, E.E., Halbrendt, N.O., and McNellis, T.W. (2013). The fire blight pathogen Erwinia amylovora requires the rpoN gene for pathogenicity in apple. Mol Plant Pathol 14:838-843.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Singh, D.K., Laremore, T.N., Smith, P.B., Maximova, S.N., and McNellis, T.W. (2012). Knockdown of FIBRILLIN4 gene expression in apple decreases plastoglobule plastoquinone content. PLoS One 7:e47547, doi:10.1371/journal.pone.0047547
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: VanKirk, J.R., Isard, S.A., Cardwell, K.F., and Draper, M.A. (2012). The ipmPIPE: Overview, Lessons, Opportunities, and Challenges. Journal of Integrated Pest Management 3:C1-C7, doi: http://dx.doi.org/10.1603/IPM11015
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Neufeld KN, Isard SA, Ojiambo PS (2013). Relationship between disease severity and escape of Pseudoperonospora cubensis sporangia from a cucumber canopy during downy mildew epidemics. Plant Pathology, doi:10.1111/ppa.12040


Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: From Dr. McNellis' program, a paper was published describing project findings regarding apple tree rootstock effects on apple tree resistance to fire blight disease in the journal BMC Genomics, which is a venue where other plant genomics researchers will see the results. Our findings described in the journal indicate that particular genes in apple trees can be used as indicators of resistance status to fire blight, and can be used as predictors of fire blight resistance status. The results also conclusively show effects of rootstock genotype on the disease resistance status of apple scions. Our publication provides this information to interested parties in a peer-reviewed journal format. In addition, results were presented at the national meeting of the American Phytopathological Society in Providence, RI, regarding the potential role of quorum sensing in fire blight disease processes in apple, and the role of plastoquinone antioxidants in the progression of fire blight disease in apple trees. From Dr. Isard's program, The Integrated Aerobiology Modeling System to forecast the aerial movement of soybean rust, P. pachyrhizi, in the U.S., Mexico and Canada has been operated with international observation network information as part of the ipmPIPE from 2005 to present. Predictions of distribution and timing of disease matched field observations and soybean rust has not been detected in PA. Smartphone applications have been developed and deployed as a "push" technology to enable Extension specialist to input observations from the field and to reach crop consultants and growers with pest decision support information in a real-time framework. Products include maps created by day degree, infection and atmospheric transport models. The site includes a publicly available map with summarized data and products. The PIPE system has recently achieved sustainability based on a business model by which the corn and soybean industries and grower organizations support monitoring and information dissemination activities of interest to all stakeholders. From Dr. Uddin's program, an epidemiological study on gray leaf spot of perennial ryegrass was conducted to determine the effects of intermittent and interrupted leaf wetness periods on gray leaf spot of perennial ryegrass turf. The study revealed that higher frequencies and durations of dry periods in the free moisture regime significantly reduced gray leaf spot disease. There were strong relationships between frequency or duration of dry periods and the rate of decrease of disease incidence or severity. The results were disseminated to golf course industry through presentations in trade conferences and industry expositions. Additionally, the information was made available to turfgrass managers through regional meetings, including presentation of posters and flyers. Presentation of the results was also made at the national meeting of the American Phytopathological Society. From Dr. Gildow's program, viral mechanisms of evolution in host were analyzed and discovered. PARTICIPANTS: Timothy McNellis serves as lead investigator for fire blight projects, including graduate and undergraduate student training in fire blight disease studies. He is assisted by Senior Research Assistant Judith Sinn, working on fire blight disease resistance research and genetics of Erwinia amylovora pathogenicity in apple. Graduate student Laura Ramos is doing her doctoral research in Dr. McNellis' laboratory, studying the genetic basis of pathogenicity in the fire blight bacterium Erwinia amylovora. Graduate student Xin Lin is doing her Ph.D. degree research with Dr. McNellis studying plant genetics related to bacterial disease resistance. Scott A. Isard, P.I. on the aerobiology forecasting work, identifies research objectives, seeks research funding, and guides graduate students and research staff in developing and conducting experiments. Marcelo Chamecki, Assistant Professor in Meteorology, collaborates on studies of wheat stem rust spread. Julie Golod, Project Assistant, has been the National Coordinator of the PIPE. Simone Gleischer and Ying Pan have participated as graduate student in the project. PSU undergraduate student Kehui Zhang served as summer intern on the project in 2012. Dr. Wakar Uddin is the principal investigator for the epidemiology of turfgrass disease project, including graduate student training in turfgrass disease management studies. Research Assistant Brian Aynardi, assists Dr. Uddin in turfgrass disease research projects. Graduate student Yinfei Li, is a Graduate Research Assistant, focusing her doctoral research on epidemiology, particularly evaluating the factors influencing the development of gray leaf spot of perennial ryegrass turf. Graduate Alamgir Rahman's doctoral research involves induced system resistance in gray leaf spot pathosystem. In Dr. Marilyn Roossinck's program, Dr. Justin Pita was the postdoctoral researcher working on viral endosymbiosis. TARGET AUDIENCES: Researchers in fire blight basic biology were served by Dr. McNellis' part of the project, and apple growers and pear growers will potentially be served by the project as we develop new ways to try to control fire blight disease. Dr. Isard's IPMPIPE and associated IAMS model outputs are used by Extension specialists, crop consultants, and soybean, wheat, and corn growers in the U.S., Canada and Mexico to assist with in-season management of rusts on soybean and cereal crops. Turfgrass managers in golf course industry, sports fields, landscape, and sod producers are the primary audience in Dr. Uddin's portion of this project. Researchers and county extension specialists were also served by the project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
From Dr. McNellis' program, the findings of this project show that rootstocks can help to control fire blight disease in apple trees. Previously, this possibility was hypothesized based on anecdotal evidence, but our research results now indicate this occurs with statistical support. The knowledge generated about quorum sensing and fire blight could be developed into new control measures to try to stop Erwinia amylovora from colonizing apples and pears. From Dr. Isard's program, the PIPE has had a major impact in reducing sprays applied for Asian soybean rust. PIPE increased producers' profits by between $11 and $299 million in 2005 and ca. $200 million/yr over the subsequent 5 years. It provided benefits to U.S. agencies and producers through a better understanding of the movement of migratory or invasive pests. From Dr. Uddin's program, the results of this study provides information on turfgrass canopy moisture management in ryegrass fairways in golf courses, sports fields, landscape, and sod production fields. Efficient use of water and proper irrigation scheduling to reduce the periods of heavy moisture in turfgrass canopy will help the turf managers manage gray leaf spot disease, as part of an integrated disease management strategy. Additionally, this will help maximize the effects of the chemical use to control the disease, particularly in golf course industry. From Dr. Roossinck's program, two papers are now in press on the newest studies of Cucumber mosaic virus variation in plants, as it correlates with pathogenicity. CMV-Fny, a high virulence strain with very heterogeneous populations, was compared with CMV-LS, a low virulence, low mutation frequency stain. The genetic basis of virulence and variation were both mapped to RNA 2 of the virus, with involvement of the 2b gene. The 2b gene was also implicated in controlling fixation of newly developed variants as the virus evolves. This work improves our understanding of the underlying mechanisms that can lead to virus virulence.

Publications

  • Chamecki, M., N. S. Dufault, and S. A. Isard. 2012. Atmospheric dispersion of wheat rust spores: a new theoretical framework to interpret field data and estimate downwind dispersion. Journal of Applied Meteorology and Climatology. http://journals.ametsoc.org/doi/pdf/10.1175/JAMC-D-11-0172.1.
  • Cilia, M., K. A. Peter, M. S. Bereman, K. Howe, T. Fish, D. Smith, F. Gildow, M. J. MacCoss, T. W. Thannhauser, and S. M. Gray. 2012. Discovery and targeted LC-MS/MS of purified polerovirus reveals differences in the virus-host interactome associated with altered aphid transmission. PloS ONE 7(10): e48177. http://dx.doi.org/10.1371/journal.pone.0048177.
  • Lee, S. A., B. Lehman, H. K. Ngugi, and T. W. McNellis. 2012. Requirement for a gene encoding a predicted acyl carrier protein for full virulence of the fire blight pathogen Erwinia amylovora. American Phytopathological Society Annual Meeting. Providence RI. August 4-8, 2012. (Abstract 540-P). http://www.apsnet.org/meetings/Documents/2012_Meeting_Abstracts/aps12 abP540.htm.
  • Pan, Y., S. A. Isard, and M. Chamecki. 2012. Dispersion of heavy particles emitted from area sources in the unstable atmospheric boundary layer. Boundary Layer Meteorology (In Press).
  • Pita, J. S. and M. J. Roossinck. 2012. Mapping viral functional domains for genetic diversity in plants. Journal of Virology (Accepted for Publication).
  • Pita, J. S. and M. J. Roossinck. 2012. Fixation of emerging inter-viral recombinants in Cucumber mosaic virus populations. Journal of Virology (Accepted for Publication).
  • Jensen, P. J., N. Halbrendt, G. Fazio, I. Makalowska, N. Altman, C. Praul, S. N. Maximova, H. K. Ngugi, R. M. Crassweller, J. W. Travis, and T. W. McNellis. 2012. Rootstock-regulated gene expression patterns associated with fire blight resistance in apple. BMC Genomics 13:9.
  • Singh D. K., T. N. Laremore, P. B. Smith, S. N. Maximova, T. W. McNellis. 2012. Plastoquinone partitioning in the chloroplast affects disease resistance in apple. American Phytopathological Society Annual Meeting. Providence RI. August 4-8, 2012. (Abstract 545-P). http://www.apsnet.org/meetings/Documents/2012_Meeting_Abstracts/aps12 abP545.htm.
  • Sutrave, S., C. Scoglio, S. A. Isard, J. M. S. Hutchinson, and K. A. Garrett. 2012. Identifying Highly Connected Counties Compensates for Resource Limitations when Evaluating National Spread of an Invasive Pathogen. PLoS ONE 7: e37793. http://dx.doi.org/10.1371/journal.pone.0037793.