Location: Corn, Soybean and Wheat Quality Research
Project Number: 5082-22000-001-000-D
Project Type: In-House Appropriated
Start Date: May 22, 2017
End Date: May 9, 2022
Objective:
1. Monitor and identify emerging insect-transmitted pathogens of maize and soybean using standard and bioinformatics-based approaches, and develop management strategies. Sub-objective 1.A: Identification and diagnosis of viruses and virus populations in maize. Sub-objective 1.B: Develop tools to characterize emerging maize-infecting viruses. Sub-objective 1.C: Characterize role of E. coryli in damage caused by BMSB.
2. Identify virus factors important for pathogenesis, transmission and host interactions, and develop virus systems for gene discovery and functional analysis in maize and other cereals. Sub-objective 2A: Characterize Maize chlorotic dwarf virus factors important for pathogenesis and interactions with plant hosts. Sub-objective 2B: Develop systems for working with full-length infectious cDNAs of maize viruses. Sub-objective 2C: Define insect vector interactions with plant host and viral pathogens.
3. Identify and characterize mechanisms of action of genetic loci for virus resistance in maize. Sub-objective 3A: Identify and characterize loci providing tolerance/resistance to MCMV in maize and sorghum. Sub-objective 3B: Characterize interactions among potyviruses, MCMV and virus resistance/tolerance in maize. Sub-objective 3C: Characterize and map novel soybean quantitative trait loci (QTL) for host plant resistance to brown marmorated stinkbug (BMSB).
4. Characterize pathogen vectoring relationships of and between emerging insect pests and vectors of maize pathogens using comparative genetic and genomic analyses to identify factors that can be disrupted for disease control.
Approach:
Developing control strategies for insect-transmitted diseases requires knowledge about the pathogen, crop host, disease vector, and interactions among them and with the environment. Under Objective 1 we will combine standard serological and molecular approaches for diagnostics with next generation sequencing (NGS) approaches to identify and define population structures for emerging insect-vectored pathogens of maize and soybean. We will use this information to develop targeted molecular and serological diagnostics for emerging diseases, identify virus vectors and identify other factors important for disease development and spread. The identity and populations of yeast of yeast transmitted to soybean by brown marmorated stink bug (BMSB) will be defined using NGS, and traditional plant pathological approaches will be used to determine its role in damage caused by the stink bug. Under Objective 2, molecular biological and biochemical approaches will be used to virual protein structure and function for Maize chlorotic dwarf virus. Molecular biological approaches will be used to develop and improve infectious cloned cDNAs for maize infecting viruses. For Objective 3, methods we previously developed for phenotypic analysis of plant responses to Maize chlorotic mottle virus and BMSB will be used to map resistance in biparental and association mapping populations using molecular and NGS approaches for genotyping. Interactions between known maize potyvirus resistance genes and potyvirus isolates will be assessed in near isogenic lines carrying defined resistance genes and alleles using the development of symptoms and virus titer in inoculated plants. NGS genomic and transcriptomic analyses of leafhoppers feeding on healthy and virus-infected plants under different environmental conditions will be used to develop comparisons of leafhopper species.
