Location: Horticultural Crops Research
2009 Annual Report
The overall goal of our research is to identify the genetic mechanisms that enable oomycete pathogens to overcome host defenses, using the soybean pathogen Phytophthora sojae as a model.
Three small RNA libraries from P. infestans, P. sojae and P. ramorum were produced and sequenced. Two small RNA size classes, with peaks at 21 and 25 nucleotides, were identified in each library. In other species, multiple size classes are reflective of distinct biogenesis pathways. These peaks were identified in analyses of both total reads and unique sequences. A database and genome viewer were developed to facilitate analysis of the small RNA component in Phytophthora. Putative RNA silencing proteins were tentatively identified in the P. sojae, P. infestans, and P. ramorum genomes, with known, functional DCL, RDR, AGO from plants, animals, fungi and protists as query sequences. The identification of two predicted DCL proteins in Phytophthora immediately suggests that the two small RNA size classes identified in the small RNA libraries sequenced to date could be formed through distinct DCL functions. Cloning and sequencing of mRNA and DNA for DCL and RDR are in progress.
This project addresses CSREES goal #3: To enhance protection and safety of the Nations agriculture and food supply under the category of “Fundamental research: Research testing scientific hypotheses and providing basic knowledge that enables advances in applied research and from which major conceptual breakthroughs are expected to occur.” It addresses the following program priority of 51.0 Microbial Genomics (B): Functional Genomics of Microorganisms: “1) Characterization of mechanisms of pathogenicity by microorganisms”.
Methods of ADODR monitoring included meetings, e-mail or other types of written correspondence.