Gene Pool Screening for Development of Phytophthora Resistance
Genetic Improvement of Fruits and Vegetables
2013 Annual Report
1a.Objectives (from AD-416):
Utilizing results of our prior research in potato where we described the role of xyloglucan-specific endoglucanase genes and xylogucan-specific endoglucanase inhibitor proteins (XEGIP) in Phytophthora host-pathogen interaction, we will identify, characterize and clone XEGIP encoding genes in the Phytophthora resistant pepper CM 334 and evaluate their efficacy against Phytophthora species infection in transgenic tomato and potato. We expect that the XEGIP gene pool from pepper line CM334 will be a valuable resource for developing potential resistance to Phytophthora infestans, and P. capsici in tomato, and to P. infestans and P. erythroseptica in potato.
1b.Approach (from AD-416):
ARS has acquired the basic genetic knowledge of XEGIP encoding genes in potato. This information will be used by both parties to jointly identify potential XEGIP encoding genes in pepper. The Cooperator has access to the CM334 pepper line and control plants, and has samples that have been inoculated with P. capsici. The Cooperator will identify genomic and/or cDNA clones of pepper XEGIP genes for use in transgenic tomato and potato development. XEGIP gene expression studies will also be performed by real–time PCR or microarray analysis.
Plants have many methods for reducing damage caused by disease and stress. Plants can produce inhibitor proteins that counteract the microbial enzymes that allow for plant infections. Recently discovered inhibitor proteins termed XEGIPs are now being shown to protect the plants. Inhibitor protein genes found in potato and tomato, have now been found in pepper, which is related to potato and tomato. They are quite similar, indicating that when a function is found for a potato XEGIP there may be a similar gene with a similar function in pepper. Multiple inhibitor protein genes have now been found in pepper, and they will be analyzed further to determine their function. This information will be used by breeders and other scientists to improve disease resistance.