Progress 09/01/09 to 08/31/14
Outputs
Target Audience: The target audience included peer scientists, postdocs, graduate and undergraduate students, as well as professionals in the apple industry. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? We have trained the following three graduate students: Fan Yang, In-Young Kim, and Nichole Busdieker, along with postdoctoral research associate, M. Awais Khan, along with an undergraduate student Edward Northrup. Professional development for PI, Schuyler Korban, and Co-PIs, Youfu "Frank" Zhao, George Sundin, Kevin Kim, Larry Pusey, Hyungsoo Choi, and Lea Nogueira. How have the results been disseminated to communities of interest? Reports have been disseminated via scientific publications, as well as via apple grower conferences and meetings, as well as to private industry via oral communication. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We have dissected the genetic basis of fire blight resistance in apple using both QTL and genome-wide association mapping. Based on an F1 progeny of the apple 'Coop 16' x 'Coop 17' and a genome wide association study (GWAS) mapping population of Malus accessions (species, old and new cultivars and selections), new QTLs and associations have been identified. A total of three QTLs for resistance to fire blight, with above 95% significant LOD threshold value of 2.5, have been identified on linkage groups (LGs) 02, 06, and 15 of the apple genome with phenotypic variation explained (PVE) values of 14.7, 20.1, and 17.4, respectively. Although elevated p-values with signals for marker-trait associations are observed for some linkage groups, these are not found to be significant. However, a total of 34 significant associations, with p-values >0.02, have been detected including eight for lesion length at 7 days following inoculation (PL1), 14 for lesion length at 14 days following inoculation (PL2), and 12 for shoot length. In our effort to identify synthetic compounds that can control fire blight disease, we conducted a microarray analysis of Erwinia amylovora treated with synthetic compounds 3 and 9 identified a total of 588 significantly differentially expressed genes. Among them, 95 and 78 genes were activated and suppressed by both compounds, respectively, when compared with the dimethylsulphoxide (DMSO) control. The expression of the majority of T3SS genes in Erwinia amylovora, including hrpL and the avrRpt2 effector gene, was suppressed by both compounds. Compound 3 also suppressed the expression of amylovoran precursor and biosynthesis genes. However, both compounds induced significantly the expression of glycogen biosynthesis genes and siderophore biosynthesis, regulatory and transport genes. Furthermore, many membrane, lipoprotein and exported protein-encoding genes were also activated by both compounds. Similar expression patterns were observed for compounds 1, 2, and 4. Using crab apple flower as a model, compound 3 was capable of reducing disease development in pistils. These results suggest a common inhibition mechanism shared by salicylidene acylhydrazides and indicate that small molecule inhibitors that disable T3SS function could be explored to control fire blight disease. A "proof of concept" of the successful use of a microencapsulated biocontrol agent, E325, against Erwinia amylovora, was developed and could serve as a model for further studies on the development of effective plant disease management strategies. Controlled release of E325 was achieved by separately adjusting alginate concentrations in the shell and core solutions, and by modifying the AMC size. Viability of E325 was monitored via fluorescent staining, revealing either lack of or minimal stress during or after encapsulation. Proliferation of E325 within AMCs, followed by their subsequent release and colonization activities within confines of apple flowers were studied under different encapsulation conditions using rfp-labeled E325 to obtain highly promising results.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Khan, M.A., Olsen, K.O., Sovero, V., Kushad, M.M. and Korban, S.S. Fruit quality traits have played critical roles in domestication of the apple. The Plant Genome 7: doi:10.3835/plantgenome2014.04.0018.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, F., Korban, S.S., Pusey, P.L., Elofsson, M., Sundin, G.W. and Zhao, Y. Small-molecule inhibitors suppress the expression of both type III secretion and amylovoran biosynthesis genes in Erwinia amylovora. Molecular Plant Pathology 15: 4457.
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Progress 09/01/12 to 08/31/13
Outputs
Target Audience: The target audience include peer scientists, postdoctoral research associates, graduate and undergraduate students, and the apple industry Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? We have trained agraduate student, Fan Yang, and postdoctoral research associate, M. Awais Khan, along with an undergraduate student Edward Northrup. Professional development for PI, Schuyler Korban, and Co-PIs, Youfu Frank Zhao, George Sundin, Kevin Kim, Larry Pusey, Hyungsoo Choi, and Lea Nogueira. How have the results been disseminated to communities of interest? Reports have been disseminated via scientific publications, as well as via apple grower conferences and meetings, as well as to private industry via oral communication. What do you plan to do during the next reporting period to accomplish the goals? Continue to conduct additional experiments, analyze data, and prepare manuscripts for publication.
Impacts
What was accomplished under these goals?
We have dissected the genetic basis of fire blight resistance in apple using both QTL and genome-wide association mapping. Based on an F1 progeny of the apple ‘Coop 16’ x ‘Coop 17’ and a genome wide association study (GWAS) mapping population of Malus accessions (species, old and new cultivars and selections), new QTLs and associations have been identified. A total of three QTLs for resistance to fire blight, with above 95% significant LOD threshold value of 2.5, have been identified on linkage groups (LGs) 02, 06, and 15 of the apple genome with phenotypic variation explained (PVE) values of 14.7, 20.1, and 17.4, respectively. Although elevated p-values with signals for marker-trait associations are observed for some linkage groups, these are not found to be significant. However, a total of 34 significant associations, with p-values >0.02, have been detected including eight for lesion length at 7 days following inoculation (PL1), 14 for lesion length at 14 days following inoculation (PL2), and 12 for shoot length. In our effort to identify synthetic compounds that can control fire blight disease, we conducted a microarray analysis of Erwinia amylovora treated with synthetic compounds 3 and 9 identified a total of 588 significantly differentially expressed genes. Among them, 95 and 78 genes were activated and suppressed by both compounds, respectively, when compared with the dimethylsulphoxide (DMSO) control. The expression of the majority of T3SS genes in E. amylovora, including hrpL and the avrRpt2 effector gene, was suppressed by both compounds. Compound 3 also suppressed the expression of amylovoran precursor and biosynthesis genes. However, both compounds induced significantly the expression of glycogen biosynthesis genes and siderophore biosynthesis, regulatory and transport genes. Furthermore, many membrane, lipoprotein and exported protein-encoding genes were also activated by both compounds. Similar expression patterns were observed for compounds 1, 2 and 4. Using crab apple flower as a model, compound 3 was capable of reducing disease development in pistils. These results suggest a common inhibition mechanism shared by salicylidene acylhydrazides and indicate that small molecule inhibitors that disable T3SS function could be explored to control fire blight disease.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Khan, M.A., Y. Zhao, and S.S. Korban. Identification of genetic loci associated with fire blight resistance in Malus through combined use of QTL and association mapping. Physiologia Plantarum 148:344353.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2013
Citation:
Yang, F., S.S. Korban, P.L. Pusey, M. Elofsson, G. W. Sundin, and Y. Zhao. Small molecule inhibitors suppress expression of both type III secretion and amylovoran biosynthesis genes in Erwinia amylovora. Molecular Plant Pathology DOI: 10.1111/mpp.12064.
- Type:
Book Chapters
Status:
Submitted
Year Published:
2013
Citation:
Korban, S.S., Y. Han, J. Wu, and S. Zhang. Map-based cloning in apple and pear. In: A. Dinghra and K. Evans (eds.) Genomics, Genetics and Breeding of Fruit Trees. Springer-Science, New York.
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: 1) Identified a total of 12,000 new apple Single Nucleotide Polymorphism (SNP) markers from expressed sequence tag (EST) sequences; this has been submitted to the Genome Database for Rosaaceae (GDR); 2) Constructed a new 1,536 apple EST-derived SNP GoldenGate genotyping platform; 3) A global apple consensus map was constructed; 4) A 'proof of concept' of the successful use of a microencapsulated biocontrol agent, E325, against Erwinia amylovora was achieved; 5) Presented scientific papers at the Annual Meetings of the American Society for Horticultural Science in Miami, FL; 6) A total of nine grower training sessions in Michigan and New York and four sessions targeting industry fruit Extension workers were given on fire blight management including biological control and responding to streptomycin resistance; 7) Seven Extension newsletter articles were written and disseminated via web and grower magazines; 8) A total of four educational videos on fire blight have been completed, and will be posted on Youtube. These include the following videos: (a) Biological control of fire blight; (b) Early season biology of the fire blight pathogen Erwinia amylovora; (c) Fire blight: Pruning shoot blight strikes; and (d) Fire blight : Shoot blight development. PARTICIPANTS: The following individuals worked on this project: PIs - Korban, S.S., Zhao, Y., Nogueira, L., Kim, K., Choi, H., Sundin, G. and Pusey, P.L. Partner organizations include the University of Illinois, USDA-ARS, and Michigan State University. The following personnel were also involved: Postdoctoral research associate: M. Awais Khan; Graduate students: Dongping Wang, Nicole Busdieker; Lab resesearch assistant: Gayle McGhee; Laboratory resarch technician: Gail Ehret; and Undergraduate student: Edward Northrup. TARGET AUDIENCES: This project is targeted toward peer scientists, the apple industry, apple growers, apple grower organizations, and the chemical and formulations industries. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
To identify genes for resistance for fire blight (incited by Erwinia amylovora) from our apple mapping population, we searched for new molecular markers, single nucleotide polymorphism (SNP), from expressed sequence tags (ESTs). In total, 37,807 SNPs were identified with an average of one SNP every 187 bp from a total of 6,888 unique EST contigs. A total of 12,299 SNPs, representing 6,525 contigs, fit the selected criterion of ≥ 60 bp sequences flanking a SNP position. Of these, 1,411 SNPs were validated using four apple genotypes. These SNPs were used to construct a 1,536 apple SNP GoldenGate genotyping platform that was used to screen our apple mapping population following greenhouse inoculation of plants with E. amylovora. Moreover, this SNP platform was also used to construct a new dense genetic map for apple, and a global consensus map was then established by combining this new map with four other existing maps of apple. To determine the role(s) of the amyR gene in E. amylovora virulence, we pursued phenotypic characterization of a mutant strain as well as overexpression of amyR in a wild-type (WT) strain of E. amylovora. It was revealed that amyR acts as a general suppressor of virulence factors, and thus of overall virulence in host plants. Consistent with amylovoran production, an inverse correlation was observed between in vitro expression of amyR and that of amylovoran biosynthetic genes. However, both the amyR knockout mutant and over-expression strains showed reduced levan production, another exopolysaccharide produced by E. amylovora. Virulence assays demonstrated that while the amyR mutant was capable of inducing higher disease symptoms than that of the WT strain, those strains over-expressing amyR did not incite disease on apple shoots or leaves, and only caused mild disease symptoms on immature pear fruits. Microarray studies revealed that amylovoran biosynthesis and related membrane protein-encoding genes were highly expressed in the amyR mutant, but down-regulated in amyR over-expression strains in vitro. In our continued effort to microencapsulate the biocontrol agent Pantoea agglomerans strain E325 (E325), viability of E325 was monitored via fluorescent staining revealing either lack of or minimal stress during or after encapsulation. Proliferation of E325 within alginate microcapsules (AMCs), followed by their subsequent release, under different encapsulation conditions, and colonization activities within confines of apple flowers were studied using rfp-labeled E325. Highly promising results were obtained. In other short-term fire blight control methods, we evaluated the efficacy of experimental antibiotics and biological control agents for blossom blight control. This work confirmed the efficacy of two formulations of the experimental antibiotic kasugamycin for blossom blight control under Michigan conditions. Levels of control were similar to those observed with streptomycin. Additional experimental treatments using bacterial and yeast antagnoist biological control agents resulted in increased control compared to nontreated trees; however, these materials were not as effective as kasugamycin or streptomycin.
Publications
- Khan, M.A., Han, Y., Zhao, Y., Trogio, M. and Korban, S.S. 2012. A multi-population consensus genetic map reveals inconsistent marker order among maps likely attributed to structural variations in the apple genome. PLoSOne 7(11): e47864. doi:10.1371/journal.pone.0047864
- Khan, M.A., Han, Y., Zhao, Y.F. and Korban, S.S. 2012. A high-throughput apple SNP genotyping platform using the GoldenGateTM assay. Gene 494:196-201.
- Khan, M.A., Zhao, Y. and Korban, S.S. 2012. Molecular mechanisms of fire blight resistance in Rosaceae. Plant Molecular Biology Reporter 30: 247-260.
- Wang, D., Korban, S.S., Pusey, P.L. and Zhao, Y. 2012. AmyR is a novel negative regulator of amylovoran production in Erwinia amylovora. PLoSOne 7(9): e45038. Doi:10.1371/journal.pone.0045038.
- Kim I.-Y., Pusey, P.L., Zhao, Y., Korban, S.S., Choi, H. and Kim, K. 2012. Controlled release of Pantoea agglomerans E325 for biocontrol of fire blight disease of apple. Journal of Controlled Release 161: 109-115.
- Wang, D., Qi, M., Calla, B., Korban, S.S., Clough, S.J., Sundin, G.W., Toth, I. and Zhao, Y. 2012. Genome-wide identification of genes regulated by the Rcs phosphorelay system in Erwinia amylovora. Molecular Plant-Microbe Interactions 25: 6-17.
- McGhee, G.C., Sundin, G.W. and Ehret, G.R. 2012. Applications of Actigard as a drench and foliar spray in the control of fire blight, 2011. Plant Dis. Mgmt. Rep. 6:PF011.
- Sundin, G.W., Ehret, G.R., Forton, T.T. and McGhee, G.C. 2012. Fire blight control on Jonathan apple with Kasumin in 2011. Plant Dis. Mgmt. Rep. 6:PF004.
- Sundin, G.W., Ehret, G.R., McGhee, G.C. and Lesniak, K.E. 2012. Efficacy of Westbridge Blossom Protect and Apogee in controlling fire blight on 'Jonathan' apple, 2011. Plant Dis. Mgmt. Rep. 6:PF005.
- Han Y., Vimolmangkang, S., Soria-Guerra, R.E. and Korban, S.S. 2012. Introduction of apple ANR genes into tobacco inhibits expression of both CHI and DFR genes in flowers and leading to loss of anthocyanin. Journal of Experimental Botany 63: 2437-2447.
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: 1. Collected disease rating data on our apple mapping population, consisting of 120 seedlings of the cross Coop 17 x Coop 16, following two sets of inoculations with a suspension culture of Erwinia amylovora. This experiment was conducted in the greenhouse. 2. Collected disease rating data on a Malus core collection, consisting of 170 Malus accessions, following one set of inoculation with a suspension culture of Erwinia amylovora. This experiment was conducted in the greenhouse. 3. Presented scientific papers at conferences in Poland and U.S. 4. Completed one PhD Thesis and one M.S. Thesis 5. Publications noted below. PARTICIPANTS: The following individulas have worked on this project: PIs, Korban, S.S., Zhoa, Y., Nogueira, L., Kim, K., Choi, H., Sundin, G. and Pusey, P.L. Partner organizations include the University of Illinois, USDA-ARS, and Michigan State University. The following personnel were also involved: Postdoctoral research associates - M. Awais Khan and Danman Zheng; Graduate students: Dongping Wang and Nicole Busdieker TARGET AUDIENCES: This project is targeted towards peer scientists, the apple industry, apple grower organizations, and the chemical and formulations industries. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
To identify genes involved in response to the fire blight pathogen Erwinia amylovora in apple (Malus x domestica), expression profiles were investigated using an apple oligo (70-mer) array representing 40,000 genes. Blossoms of a fire blight susceptible apple cultivar Gala were collected from trees growing in the orchard, placed on a tray in the laboratory, and spray-inoculated with a suspension of E. amylovora at a concentration of 108 cfu/ml. Uninoculated detached flowers served as controls at each time point. Expression profiles were captured at three different time points post-inoculation at 2, 8, and 24 h, along with those at 0 h (un-inoculated). Over the three time points post-inoculation, 365 genes were commonly up-regulated and 374 genes were commonly down-regulated. Both sets of genes were classified based on their functional categories. The majority of up-regulated genes were involved in metabolism, signal transduction, signaling, transport, and stress response. We have also comparatively characterized the Erwinia RcsC and its homologs from various enterobacteria. Our results showed that expression of Erwinia rcsC gene suppressed amylovoran production in various amylovoran over-producing wild type (WT) or mutant strains, indicating net phosphatase activity of the Erwinia RcsC. Domain swapping experiments indicated that replacement of the E. coli RcsC sensor domain by those of Erwinia and Yersinia partially restored virulence of the Erwinia rcsC mutant; whereas chimeric constructs containing the sensor domain of E. coli RcsC could not rescue virulence of the Erwinia rcsC mutant on apple. To investigate whether there is a correlation between E. amylovora virulence and levels of virulence gene expression, four wildtype strains (Ea1189, Ea273, Ea110, and CFBP1430), widely used in studies of E. amylovora pathogenesis, have been analyzed and compared. E. amylovora strains Ea273 and Ea110 elicited higher severity of disease symptoms than those of Ea1189 and CFBP1430 on apple cv. Golden Delicious and G16 apple root stock plants but not on susceptible Gala plants. In addition, Ea273 and Ea110 elicited severe hypersensitive responses within shorter periods of time at lower inoculum concentrations than those of Ea1189 and CFBP1430 on tobacco plants. Further molecular analyses have revealed that amylovoran production and expression of both amylovoran (amsG) and T3SS (dspE and hrpL) genes were significantly higher in Ea273 and Ea110 than those in Ea1189 and CFBP1430. As we pursue microencapsulation of the biocontrol agent Pantoea agglomerans strain E325 (E325), an antagonist of E. amylovora, we have been able to design and fabricate uniform core-shell alginate microcapsules (AMCs), 60-300 μm in diameter, to encapsulate E325 within the core, along with nutrients, to preserve viability and promote proliferation. Controlled release of E325 was achieved by separately adjusting alginate concentrations in the shell and of core solutions, and by modifying sizes of AMCs. Continued experiments on this are under way.
Publications
- Sarowar, S., Zhao, Y., Soria-Guerra, R.E., Ali, S., Zheng, D., Wang, D. and Korban, S.S. 2011. Expression profiles of differentially regulated genes during early stages of apple flower infection with Erwinia amylovora. Journal of Experimental Botany 62: 4851-4861.
- Wang, D., Korban, S.S., Pusey, L. and Zhao, Y. 2011. Characterization of the RcsC sensor kinase from Erwinia amylovora and other enterobacteria. Phytopathology 101: 710-717. This is a Cover Page article.
- Khan, M.A., Han, Y., Zhao, Y.F., and Korban, S.S. 2011. A high-throughput apple SNP genotyping platform using the GoldenGateTM assay. Gene (In Press).
- Khan, M.A., Zhao, Y. and Korban, S.S. 2011. Molecular mechanisms of fire blight resistance in Rosaceae. Plant Molecular Biology Reporter DOI 10.1007/s11105-011-0334-1 (In Press).
- Wang, D., Korban, S.S., Clough, J.S., Calla, B., Sundin, G. and Zhao, Y. 2011. Regulatory network of amylovora biosynthesis in Erwinia amylovora. Acta Horticulturae 896: 195-202.
- Sarowar, S., Guerra, R., Wang, D., Zheng, D., Korban, S.S. and Zhao, Y. 2011. Transcriptome analysis of apple blossoms after challenge with the fire blight pathogen Erwinia amylovora. Acta Horticulturae 896: 245-251.
- Khan, M.W. and Korban, S.S. 2011. SNP discovery using apple ESTs from public database and experimental validation. Abstracts of the American Society of Plant Biology - P15039.
- Busdieker N. 2011. Welfare effects of new fire blight control methods on the U.S. apple industry. M.S. Thesis, University of Illinois (Completed).
- Wang, D. 2011. Regulation of amylovoran biosynthesis in Erwinia amylovora. Ph.D. Thesis, University of Illinois (Completed).
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: To develop biological methods of control of Erwinia amylovora, 16 small molecule chemicals reported to be effective against type III secretion systems (T3SS) of enterobacteria have been selected and tested. Among these, three strongly inhibited the hypersensitive response (HR) and another weakly inhibited HR on tobacco. Several promoter-GFP plasmids (hrpL, dspE, hrpN, and hrpA) and type three secretion mutants (hrpA, dspE, hrpN and hrpL) have been constructed. Testing of these chemical compounds on gene expression and protein secretion is underway. To improve stability of the biocontrol agent Pantoea agglomerans E325 in formulations used for fire blight management, an osmoadaptation approach, by combining saline stress and osmolyte amendment in the bacterial growth medium, was used. This approach significantly improved survival of E325 during freeze-drying and subsequent storage. The effect of osmoadaptation on survival of E325 on apple blossom surfaces under dry conditions in the U.S. was studied. Although this did not change bacterial survival on surfaces of blossom stigmas, osmoadapted E325 was more tolerant of osmotic pressure in sugar-rich nectaries where infection occurs. To develop a micro-/nano-delivery system for fire blight control agents (FBCAs), experiments were conducted to identify the appropriate material for encapsulation. Alginate has been identified as a candidate material for encapsulating FBCAs. Moreover, processing protocols to fabricate alginate microcapsules (AMCs) suitable for encapsulating FBCAs have been established. Using these protocols, AMCs of different sizes have been fabricated and successfully used to encapsulate E325. In vitro release of E325 encapsulated in AMC have been conducted. To pursue genomic analysis of genes and/or quantitative trait loci (QTL) associated with fire blight resistance, a replicated apple planting of 118 segregating individuals from a mapping population of Co-op 16 X Co-op 17 along with the two parents were grafted and grown in the greenhouse. Young shoots were inoculated with E. amylovora strain EA 273. After three days, disease progress (lesion length) was measured at three time points, and lesion length data were subjected to ANOVA. Moreover, SNPs were identified from Malus EST sequences by aligning sequences from 14 Malus genotypes. About 53,000 SNPs were identified, and sequences of corresponding SNPs were annotated. High-quality SNPs with similarity to disease-related genes were given priority for designing a SNP genotyping assay. To assess economic benefits of biocontrol methods and of developing new fire blight resistant apples, an extensive literature review and a collection of background information in collaboration with apple growers have been done, and a formulation model is being developed. Outreach programs for comprehensive management systems of fire blight are underway. Dr. Sundin delivered eight presentations to growers and one presentation to extension agents on fire blight management that included information on biotechnology and novel methods for control. He also wrote four articles for MSU IPM CAT Alert newsletter and conducted 13 on-farm site visits with growers. PARTICIPANTS: The following have worked on the project: PIs: Korban, S.S.; Zhao, Y.; Nogueira, L.; Kim, K.; Choi, H.; Sundin, G.W.; and Pusey, P.L. Collaborator: Tim Smith. Partner Organizations: University of Illinois, Michigan State University, USDA-ARS, and Washington State University. Training and Professional Development Provided To: Postdoctoral research Associates M. Awais Khan, Sujon Sarwar, and Danman Zhengand; Graduate Students Dongping Wang and Nichole Busdieker; and Undergraduate Student Hao Feng. TARGET AUDIENCES: This work is targeted towards peer scientists, apple industry, apple growers organizations, apple growers, as well as the chemical and formulations industry. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The T3SS system is a potent virulence mechanism shared by a broad spectrum of pathogenic gram-negative bacteria that infect both plant and mammalian hosts by injecting effector proteins into host cells. Identification of small molecule inhibitors, virulence inhibitors known to be effective against mammalian pathogens, are also effective against Erwinia amylovora, indicating type III secretion system is a universal target for developing novel antibacterial agents. This is the first such study conducted on plant pathogenic enterobacteria. The osmoadaptation approach used in this project significantly improved survival of E325 during freeze-drying and subsequent storage prior to applying it in the orchard. This modified protocol has prompted a change in the commercial production and formulation of E325. The first effort on developing a micro-/nano-delivery system for fire blight control agents has led to promising results in encapsulating the biological control agent E325. In addition, preliminary studies indicate that controlled release of E325 from AMCs is achievable under laboratory conditions. Genomic analysis of fire blight resistance genes is underway, and a Single Nucleotide Polymorphism (SNP) chip enriched for sequences involved in disease resistance is being developed. A first formulation model to study the economic benefits of biocontrol methods for fire blight and the development of fire blight resistant apple cultivars is being developed. We are currently working on a partial equilibrium model for the apple industry, based on a surplus maximization approach. This would provide the best opportunity to carefully evaluate the impact of the biocontrol and genomic technologies. The details of the model thus far, including prices, costs, and fire blight specifics, are based on previous research and discussions with individuals in the apple industry. The model will be fine-tuned once we incorporate data from the apple industry, via surveys and information from other industry sources. Once technology specific data are gathered, we will be able to build that into the model to evaluate the full effect that these technologies will have on the apple industry. This will aid in promoting these technologies to apple growers. Outreach efforts to educate growers on fire blight control management systems and biotechnology have been developed and these grass roots efforts have been promoted in three U.S. states. These grower meetings were located in Michigan (5), New York (2), and Wisconsin (1). In addition, a poster was presented in Michigan detailing problems with streptomycin resistance in E. amylovora and the need for alternate control methodologies. A project website is under construction, http://fireblight.nres.uiuc.edu/index.html, and will become live shortly.
Publications
- Wang, D., Korban, S.S. and Zhao, Y. F. 2010. Molecular signature of differential virulence in natural isolates of Erwinia amylovora. Phytopathology 100:192-198.
- Sarowar, S., Zhao, Y.F., Guerra, R., Ali, S., Zheng, D., Wang, D. and Korban, S.S. 2010. Expression profiles of differentially regulated genes during Erwinia amylovora infection of apple blossoms. Genome (Accepted).
- Sarowar, S., Guerra, R., Wang, D., Zheng, D.M., Korban, S.S. and Zhao, Y.F. 2010. Transcriptome analysis of apple blossom following challenge with the fire blight pathogen Erwinia amylovoran wild type and mutant strains. Acta Horticulturae (Accepted).
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