COVER CROP CASCADES CAN BENEFIT MYCORRHIZAE-ASSOCIATED MAIZE RESISTANCE TO INSECT PESTS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1014767
• Grant No.: 2018-67013-27402
• Project No.: PENW-2017-06145
• Proposal No.: 2017-06145
• Program Code: A1102
• Project Start Date: Jan 1, 2018
• Project End Date: Dec 31, 2021
• Grant Year: 2018

Project Director
Ali, J. G.

Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505

Performing Department
Entomology

Non Technical Summary
A priority area for this program is research investigating how multiple management components can be integrated to enhance plant resilience to stressors and improve productivity. We have preliminary data suggesting that the species of cover crop farmers choose has legacy effects on the subsequent corn crop's resistance to the European corn borer, and that this legacy is mediated by soil fertility and/or mycorrhizal colonization. The goal of this proposal is to discover mechanisms that control the cascade of interactions linking cover crops, soil fertility, and corn pest management.The proposed multidisciplinary team, consisting of a chemical ecologist (Ali), a soil biogeochemist (Kaye), a plant molecular biologist (Ray), and a community ecologist (Murrell), will address the following questions: 1) Do cover crop-induced changes in corn mycorrhizal colonization and soil nutrients affect constitutive and induced corn defenses against a variety of herbivores?; 2) Is the effect of mycorrhizae on corn defense simply caused by increased nutrient uptake?; 3) What effects do cover crop species have on attraction or repellence of corn pests? and 4) How do plants in a field setting respond to herbivore cues when grown after different cover crop species? In greenhouse and field experiments we will evaluate how three cover crop species affect crop plant resistance. We will monitor mycorrhizal colonization, corn chemical response, corn resistance to both above- and belowground pests, and their behavior. This foundational knowledge will advance the prospect that farmers could intentionally select cover crops to affect corn defense against a suite of herbivores.

Animal Health Component

0%

Research Effort Categories

Basic

60%

Applied

30%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	1510	1130	50%
211	0110	1040	50%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
1510 - Corn; 0110 - Soil;

Field Of Science
1040 - Molecular biology; 1130 - Entomology and acarology;

Keywords

arbuscular mycorrhizal fungi

chemical ecology

cover crops

plant resistance

soil ecology

Goals / Objectives
In the long-term our research will inform the use of cover crops as a practice to reduce pesticide use and reduce environmental impacts of agriculture. Currently, our understanding of cover crop-corn pest interactions is insufficient to define this practice precisely. Indeed, this is the premise of our proposal - the research we have proposed expands the applications, benefits and efficacy of cover crop use, ultimately reducing the need to manage corn pests with conventional pesticides, while enhancing our fundamental understanding of plant-microbial-insect interactions.The proposed multidisciplinary team, consisting of a chemical ecologist (Ali), a soil biogeochemist (Kaye), a plant molecular biologist (Ray), and a community ecologist (Murrell), will address the following questions: 1) Do cover crop-induced changes in corn mycorrhizal colonization and soil nutrients affect constitutive and induced corn defenses against a variety of herbivores?; 2) Is the effect of mycorrhizae on corn defense simply caused by increased nutrient uptake?; 3) What effects do cover crop species have on attraction or repellence of corn pests? and 4) How do plants in a field setting respond to herbivore cues when grown after different cover crop species? In greenhouse and field experiments we will evaluate how three cover crop species affect crop plant resistance. We will monitor mycorrhizal colonization, corn chemical response, corn resistance to both above- and belowground pests, and their behavior. This foundational knowledge will advance the prospect that farmers could intentionally select cover crops to affect corn defense against a suite of herbivores.

Project Methods
One hundred and eighty non-genetically modified corn plants will be reared in pots of soil taken from field plots of various cover crop treatments. Field soil will be collected just after cover crops are terminated in spring and before corn is planted. This allows us to examine the soil conditions to which the field corn will be exposed in a controlled environment. Of the 189 corn plants, 36 each will be reared under the following treatments: Soil from field plots with no cover crops, Soil from fallow field plots inoculated with spores of AMF Rhizophagus irregularis, soil from field plots of wheat-triticale, soil from field plots of Austrian winter pea, and soil from field plots of forage. Treatment A was selected to represent a lack of cover crop to affect AMF and soil nutrients. Treatment B will represent the practice of augmenting AMF to soil without a cover crop. Once corn plants have developed to the V3 stage (three leaf stage), twelve plants from each of the five treatments will be infested with five 1st instar ECB larvae. Similarly, twelve plants will be infested with twenty WCR neonates. Leaf tissue will be collected from ECB infested plants 24hrs post infestation while root tissue will be collected from WCR infested plants 72hrs post infestation. Leaf and root tissues will be collected simultaneously from the twelve control plants of each treatment which have not been infested with any herbivore. Performance of insects will be measured by recording the weight and survival of recovered ECB and WCR larvae. We recognize that our proposed assays are optimized for capturing herbivore induced plant responses more so than herbivore growth, therefore we are prepared to repeat a performance trial with extended periods to isolate effects on herbivore performance.All tissues collected with and without herbivory will be flash frozen in liquid nitrogen and placed in separate vials for (i) RNA extraction, (ii) phytohormone analysis, (iii) an assay of defensive proteins, Ribosome-inactivating protein2 (RIP2) and proteinase inhibitors, (iv) measurement of secondary metabolites known to deter herbivores such as DIMBOA, and (v) measurement of a suite of 12 micro- and macronutrients using acid digestion coupled with ICP emission spectroscopy analysis. Transcript abundance of several marker genes involved in plant's direct defenses in corn (i.e., MPI, RIP2) will be measured using the generated cDNA by qRT-PCR (quantitative real-time PCR). Similarly, transcript abundance of 12-oxophytodeanoic acid reductase 7(OPR7) and allene oxide synthase (AOS) involved in jasmonic acid biosynthesis, pathogenesis-related protein 5 (PR5) involved in salicylic acid-mediated defense response, ethylene insensitive protein 2 (EIN2) involved in ethylene-mediated defense response will also be measured. Since availability of phosphorous may impact the MAP-kinase pathway, which is one of the primary signal transduction pathways in plants and is known to be induced by herbivory, we will also measure the RNA levels of MAPKs in these treatments. All of these genes are known to alter their transcript abundance constitutively or upon induction by herbivores. Therefore, any changes in the relative abundance of the transcripts of these genes compared to undamaged controls will provide insight into the regulation of defense-related plant gene expression in response to AMF and cover crop treatment. In the second study, we will utilize the same plant-cover crop-AMF treatments but focus on resolving the global proteomic differences among treatments. Although genomic work is vital to understanding biological function, proteins are the downstream products ultimately shaping our physical world and interactions. Grasping the key functional proteins that distinguish our treatments not only carries information on fundamental plant responses, but also provides us with active plant machinery (proteins) that can be re-introduced and take action in plants. Furthermore, by conducting a network analysis of protein-protein interactions and correlations we can better grasp the unique pathways that regulate plant growth and vitality and its link to the plant defense mechanisms. Although we will resolve transcript abundances of marker genes and its gene products in Experiment 1a, a global proteomic analysis can lead us to plant signaling pathways and novel protein markers that are important bridges between plant growth and plant defense pathways. Although total transcriptional analyses (RNA-seq) have more often been performed in other studies, transcriptional analyses can in some ways be an incomplete substitute for proteomic data because post transcriptional regulation may occur, and gene expression are not always tightly correlated to their protein's abundance. However, such large-scale proteome data are rarely collected. Increased understanding of local and systemic defenses in corn, during above and belowground infestation, can help us interpret additional plant-herbivore interactions as large and complex biological systems having common conserved properties. The main objective of this study will be to generate protein-protein correlations and protein networks that determine which modules in the maize metabolic network are activated and form the bridge between plant growth, plant nutrition and systemic insect resistance in plants. While the other studies focus on plant responses, here we will elucidate insect pest behavior in response to variation in cover crops and AMF, thus directly addressing our other question. Based on our preliminary data demonstrating the potential for cover crop treatments to influence survival and performance of corn pests we will evaluate the cover crop/corn combination for behavioral responses of each pest species. Determination of adult and larval preference for the cover crop/corn combinations will contribute to our efforts to protect plants by identification of which combinations cause either avoidance or attraction. Indeed, many studies show that insect oviposition preference and larval attraction to plants are influenced by the defensive state of their potential host or are related to performance of their offspring. Therefore, we will study the behavioral responses of adult oviposition and larval preference to each cover crop/corn combination and analyze the odor changes associated with such responses. In order to link behavioral responses to signals emitted from host plants, volatiles will be collected from both the roots and shoot of the plants. The VOC signatures will be assessed using GC-MS to test which volatile compounds are changing in response to cover crop and AMF treatments. Plants will be placed in glass guillotine volatile collection chambers for above-belowground sampling. Air will be simultaneously drawn over plant shoots and roots at a rate of 100ml/min through VOC traps. Volatiles will be collected for 24hr after whichtraps will be rinsed with dichloromethane into vials. Compounds will be identified by comparing spectral data with those from commercially available standards and spectra from MS libraries, and confirmed by retention times of authentic standards, if available. In order to test how our results correspond with corn in a field setting, we will conduct an induction assay on maize plants grown in the cover crop treatment plots at the Russell E. Larson Agricultural Research Center at Penn State. Two major challenges arise when studying induced plant defenses in the field. Corn of an organic variety (Masters Choice MC4050) will be planted in the 4 cover crop treatment field. Once the corn has reached V3 stage, in each plot we will damage the leaves of 10 corn plants and apply to the wounds a mixture of volicitin, a well-known elicitor for plant defenses, isolated caterpillar oral secretions, and elicitors from insect frass (recombinant PR4 and EndochitinaseA protein).

Progress 01/01/18 to 12/31/21

Outputs
Target Audience: Nothing Reported Changes/Problems:The biggest issue as for everyone in the world was covid-19.For most of 2020 and the entirety of FY 2021, our research, like those of other laboratories in the U.S., was severely impacted in very difficult ways by the COVID-19 pandemic. Our research team on this project prevailed as best we could throughout this period of limited access to our labs and offices, and constraints on all sorts of research-related abilities, such as acquiring chemical materials, purchasing and delivery of materials essential for our research, and more. Regardless, our group showed tremendous progressin discovery and production of new knowledge about the various insect, insect-plant, plant-insect, and microbe-plant-insect chemical communication systems. What opportunities for training and professional development has the project provided?Covid-19 added additional limitations to our work, from the number of people that were allowed to work together, to the multiple cases among students and lab members and associated quarantine for either positive cases or exposures.The graduate students appointed to work on this grant, have had opportunities to give research talks, and also participate in developmental short courses to utilize machine learning in agriculture. This will enable us to make better use of the metabolite data we are collecting, particularly the volatile organic compound data, in order to better understand how volatile profiles relate to performance of the pest and plants. How have the results been disseminated to communities of interest?Our results are either published or in the process of getting published. Wealso gave talks at national meetings when possible. With the heavy travel restrictions this was very limited. Furthermore, our outreach plans were haulted as a result of increasing cases both summers that we planned to engage with the public. We will continue to publish our findings, and have a few talk scheduled this year that will also enable us to share our findings, if they are not canceled as they have been for the past two years. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? For our evaluations on the impacts of covercrop species on maize larval caterpillars, are now complete the insect behavioral and performance data, as well as plant defense response and hormonal signaling, and it is now published (Davidson et al. 2021). Weare still writing up and submitting our final manuscripts for response to Aphids and corn rootworm, which shouldbe submitted and published later this year.We have also recently published the impacts of covercrop species on maize susceptibility to pathogens (Ray et al. In press). We show cover crop legacy of triticale renders maize plants susceptible to fungal pathogen,Fusarium verticillioides.Our field data is complete and we have foudn very interesting imapcts of insect elicitors on maize under various covercrops. Our behavioral work was also very interesting. we have foudn that the ovipositional behavior of adult Fall Army worm, was not affected by cover crop legacy, but larvae behavior was. Larvae avoided maize plant that were in soil planted after triticale, the plant that they also preformed worse. we saw no affect on aphid behavior, and cornworm data is still beinganalyzed. All of the data is either published or in the process of being submitted for publication.?

Publications

• Type: Journal Articles Status: Published Year Published: 2022 Citation: Mason, C. J., Ray, S., Davidson-Lowe, E., Ali, J. G., Luthe, D. S., & Felton, G. W. Plant nutrition influences resistant maize defense responses to the fall armyworm. Frontiers in Ecology and Evolution, 107.
• Type: Journal Articles Status: Published Year Published: 2022 Citation: Ray, S., Wenner, N. G., Ankoma-Darko, O., Kaye, J. P., Kuldau, G. A., & Ali, J. G. (2022). Cover crop selection affects maize susceptibility to the fungal pathogen Fusarium verticillioides. Pedobiologia, 150806.
• Type: Conference Papers and Presentations Status: Other Year Published: 2022 Citation: Trase, O. & Ali, J. (2021)Investigating the role of soil legacies on root volatile emissions and below ground herbivory in maize.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Pingault, L., Varsani, S., Palmer, N., Ray, S., Williams, W.P., Luthe, D.S., Ali, J.G., Sarath, G. and Louis, J., (2021). Transcriptomic and volatile signatures associated with maize defense against corn leaf aphid. BMC PLANT BIOLOGY, 21(1), pp.1-15.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Davidson-Lowe, E., Ray, S., Murrell, E., Kaye, J., & Ali, J. G. (2021). Cover Crop Soil Legacies Alter Phytochemistry and Resistance to Fall Armyworm (Lepidoptera: Noctuidae) in Maize. ENVIRONMENTAL ENTOMOLOGY 50(4) 958967.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2022 Citation: Davidson-Lowe, E., Trase, O., Zainuddin, N., and Ali, J. Arbuscular mycorrhizal fungi mediate belowground interactions between a specialist root-feeder and its natural enemy. Insects.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2022 Citation: Ray, S., Davidson-Lowe, E., and Ali, J. Proteomic response to herbivory of maize is influenced by cover crop legacy. TBD

Progress 01/01/20 to 12/31/20

Outputs
Target Audience:During the thrid year of our project we experieince significant difficulties due to Covid-19. Our university did not allow undergraduates to return to campus, the local schools shut down in-person teaching, daycares closed and there was significant restrictions for research, lab us, and interactions over all. Thissignificantly impacted our research and progress. we were nto allowed to be in the same lab, greenhouse, or work truck for most of 2020. All of our planned outreach was canceled that summer.We werein the process of developing our strategy for our university agriculutal progress outreach events the summer of 2020 on cover crops to reach and talk with more growers and stakeholders. Changes/Problems:Again, for most of entirety of FY 2020, our research, like those of other laboratories in the U.S., was severely impacted in very difficult ways by the COVID-19 pandemic. Our research teamprevailed as best we could throughout this period of limited access to our labs and offices, and constraints on all sorts of research-related abilities, such as acquiring chemical materials, purchasing and delivery of materials essential for our research, and more. Regardless, our group showed tremendous progress this year in discovery and production of new knowledge about the various insect, insect-plant, plant-insect, and microbe-plant-insect chemical communication systems. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?We had two talks at the virtual Entomology meeting that year. All other plans were canceled due to Covid-19 What do you plan to do during the next reporting period to accomplish the goals?We hope a vaccination is developed available and we can resume work as normal. For now it seems as though it will be necessary for us to request a no cost extension as many issues arose this year.

Impacts
What was accomplished under these goals? For most of entirety of FY 2020, our research, like those of other laboratories in the U.S., was severely impacted in very difficult ways by the COVID-19 pandemic. Our research teamprevailed as best we could throughout this period of limited access to our labs and offices, and constraints on all sorts of research-related abilities, such as acquiring chemical materials, purchasing and delivery of materials essential for our research, and more. Regardless, our group showed tremendous progress this year in discovery and production of new knowledge about the various insect, insect-plant, plant-insect, and microbe-plant-insect chemical communication systems. We worked on publishing papers, many of which will be published 2021 or possible later. We made progress on the volatile analysis of our plant samples, but had significant difficultlies setting up any new experiments.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Ali, J. G., Casteel, C. L., Mauck, K. E., & Trase, O. (2020). Chemical ecology of multitrophic microbial interactions: plants, insects, microbes and the metabolites that connect them. Journal of Chemical Ecology, 46(8), 645-648.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Swyst, I. (My Student) & Ali, J.G. (2020) Arbuscular mycorrhizal fungi alters soybean resistance against herbivores in a feeding guild specific manner. Entomological Society of America. Virtual Meeting  Covid 19.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Davidson-Lowe, E.(My Student), Zainnudin, N., Ali, J.G. (2020). Opening a can of worms: Do AMF alter belowground interactions between plants, root herbivores and their natural enemies? Entomological Society of America. Virtual Meeting  Covid 19.

Progress 01/01/19 to 12/31/19

Outputs
Target Audience: During the second year of this project we have presented our research at multiple national and international meetings, two Universities, and shared our work during a multi-state group NE1501 on chemical ecology. These activities to date all mark audiences made up of mostly research scientists, research professors and extention educators. This represents interaction with mostly research communities. We are in the process of developing our strategy for our university agriculutal progress outreach events the summer of 2020 and a webinar on cover crops to reach and talk with more growers and stakeholders. Now that we have completed research with very promising data we are better alighned to present this work to the greater farming and agricultural communities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? We have provided opportunitiesfor involvement of undergraduate students and graduate students with 10 undergraduates and 5 graduate students being trained.2 graduate students obtained experience in agriculturalsystems as well as managing variety trials and conducting participatory farmresearch. They are also presenting and planning to presentat field days and professional conferences. Graduate students gained training experiences in molecular/chemical assays, and presenting. They have gained skills and experience with molecular and chemcial approaches and coordinating and communicating with farm managers and scientist partners toward experimental evaluations. The students and postdocs have co-authored manuscripts with Ali, and other papers arecurrently in prep. Ali, with one graduate student, started a collaboration to extend the covercrop work with two additional pests and setting up a trial to test if there are prelimary influences on beneficial insects. Participants and Ali are traveling to meetings to present this work this upcoming year. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?Our next steps, involve a processing the large amoutn of data we have accumulated, wiritng up and finializing manuscript for publication. We are still planing on outrech events and a webinar now that we have very promising results in the field and laboratory/greenhouse. We are continuing to move forward with our behavioral assays and are in the process of ramping up our efforts for a second field season and diesgining a system to better evaulate the induced volatiles from these plants.

Impacts
What was accomplished under these goals? Objective 1) Do cover crop-induced changes in corn mycorrhizal colonization and soil nutrients affect constitutive and induced corn defenses against a variety of herbivores? - We have found discovered significant affect of cover crop species on the AMF colonization of corn roots - We have conducted 5 majorlaboratory experiments that have tested the affects of AMF colonization on resitance towards three insect pest species. we find specificity of resistance towards each herbivore based on covercrop species. - We are currently finsihing up or chemical and proteomeanalysis from these experiments to discover the mechanisms of plant resistance this is a veyr large data set with very few studies conducted at this scale. 2) Is the effect of mycorrhizae on corn defense simply caused by increased nutrient uptake?; - We conducted two experiments in the laboratoies at the Land institute, testing nutritioanl affects on insect resistance. we are in the process of shipping these samples to PennState to analyze the volatiles, enzumes, andRNA expressed across these trials. 3) What effects do cover crop species have on attraction or repellence of corn pests? - We have conduct mutliple experiments with oviopositional and larval prefference for corn plant in soil that had either triticale, radish, pea or was fallow. We are finding significant affect on larval preferences for plants that grew after species cover crop species, btu are still working out the best strategy for ovipositional behavior. 4) How do plants in a field setting respond to herbivore cues when grown after different cover crop species? - We conducted our first field experiment this past summer with elicitors for caterpillar pests and trapping the pest on the plant to see affects of each cover crop on corn plant resistance. we found similar trends in the performance of larvae as observed in the laboratory/greenhouse experiements. we are currently processing the secondary chemistry and gene expression from these experiemnts. - For all of the above projects we have either published or are in the process of publishing these rules in peer-reviewed journals.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Ray, S., Helms, A. M., Matulis, N. L., Davidson-Lowe, E., Grisales, W., & Ali, J. G. (2020). Asymmetry in Herbivore Effector Responses: Caterpillar Frass Effectors Reduce Performance of a Subsequent Herbivore. Journal of Chemical Ecology, 46(1), 76-83.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Markovic, Dimitrije, Ilaria Colzi, Cosimo Taiti, Swayamjit Ray, Romain Scalone, Jared Gregory Ali, Stefano Mancuso, and Velemir Ninkovic. "Airborne signals synchronize the defenses of neighboring plants in response to touch." Journal of experimental botany 70, no. 2 (2019): 691-700.
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Davidson-Lowe E, Ray S, Murrell E, Kaye J & Ali JG. (2019) Cover crop legacies alter subsequent AMF colonization and herbivore resistance in maize. Gordon Research Conference for Plant-Herbivore Interactions, Ventura, CA.

Progress 01/01/18 to 12/31/18

Outputs
Target Audience:During the first year of this project we have presented our research at three national and international meetings, three Universities, and shared our work during a multi-state group NE1501 on chemical ecology. These activities to date all mark audiences made up of mostly research scientists, research professors and Extention educators. This represents interaction with mostly research communities. We are in the process of developing our strategy for our universities agriculutalprogress outreach events this summer and a webinar on cover crops to reach and talk with more growers and stakeholders. Now that we have completed research with very promising data we are better alighned to present this work to the greater farming and agricultural communities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We have a PhD student and two postdocs working on this project. we have sent them out to give research talks at various meetings and have enrolled them in adavanced training for chemical ecology and protein analysis. We meet weekly with all personnel involved in the project and give the students and postdocs opportunities to present draft papers and discuss the next steps in both the porject and their professional goals. How have the results been disseminated to communities of interest?We have giventalks and presented papers at both national and international meetings. We are planning to have a special webinar this upcoming fall depending on this season's results. What do you plan to do during the next reporting period to accomplish the goals?We will continue to make progress on the objectives. We will haveour full first setof data from the the field experiements and the proteomic datathis fall. We anticpate at least 2 more publications this year from data already collected.

Impacts
What was accomplished under these goals? The data collected to dateare domonstrating that selection of cover crop species has a species specific effect on pests of corn. It seems as though depending on the cover crop selected you can either attract or repell certain pests and benefit or reduce theperformance of certain pests. These interactions are very significant and the first of their kind. Below is a summary of our early findings and we look forward to go deeper into the mechanisms behind these observations with our proteomic work and our field studies that will take place this feild season and into next year. Plant-AMF Associations: Our data show that plant nitrogen was higher in corn planted after leguminous cover crops (pea and clover) than non-leguminous treatments. In addition, AMF colonization of corn roots is greater in plots previously planted with mycorrhizal cover crops than non-mycorrhizal or no cover crops. AMF colonization is also strongly linked to plant P concentrations , and the N:P ratio in plants is predictive of corn plant height. Many of these AMF-plant relationships were expected based on prior research; our data break new ground by bridging cover crop species' effects on AMF interactions with corn pest. Insect performance and behavior: Our data show caterpillar pest performance was reduced in corn plants grown in Triticale cover crop soil and the damage is greatest on plants that grow in non-mycorrhizal radish cover crop soils. Larvae seem to prefer plants grown in soil from triticale plots while adults prefer to oviposit on radish plants. Belowground we see that corn rootworm larvae grow and survive best on plants that were grown in soil preceded by leguminous cover crops. Plant response: Our results show that plants with both rapid growth and high percent AMF colonization had the strongest total induced defense response (sum all transcripts of defense genes). Furthermore, we see that increases in herbivore-induced defenses in plants have negative consequences for larval development.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Murrell, E. G., Ray, S., Lemmon, M. E., Luthe, D. S., & Kaye, J. P. (2019). Cover crop species affect mycorrhizae-mediated nutrient uptake and pest resistance in maize. Renewable Agriculture and Food Systems, 1-8.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Davidson-Lowe E, Ray S, Murrell E, & Ali JG. Cover-crop facilitated effects on arbuscular mycorrhizal fungi impacts resistance to herbivores from multiple feeding guilds. Oral presentation at the 2018 Annual Meeting of the Entomological Society of America; 2018 Nov 11-14; Vancouver, BC Canada.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Davidson-Lowe E, Ray S, Ali JG. Arbuscular mycorrhizal associations impact plant resistance to a belowground feeding herbivore. Poster presentation at the 2018 Annual Meeting of the International Society of Chemical Ecology; 2018 Aug 12-17; Budapest, Hungary.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Davidson-Lowe E, Ray S, Ali JG. Impact of mycorrhizal associations on plant resistance to a belowground feeding herbivore. Poster presentation at the 21st Biennial Penn State Plant Biology Symposium: Wild and Tamed Phytobiomes; 2018 Jun 19-22; University Park, PA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Davidson-Lowe E, Ray S, Murrell E, Kaye J & Ali JG. Cover crop legacies alter subsequent AMF colonization and herbivore resistance in maize. Poster presentation at the Gordon Research Conference for Plant-Herbivore Interactions; 2019 Feb 24-Mar 1; Ventura, CA.