1a.Objectives (from AD-416)
The objective of the proposed research that will be conducted at the FDWSRU is to utilize high throughput virus-induced gene silencing (VIGS) assays to investigate the role of genes necessary for resistance towards Asian Soybean Rust (ASR).
1b.Approach (from AD-416)
Genes targeted for silencing will be selected based upon information garnered from soybean gene expression studies, resistance gene mapping studies, and soybean orthologs of key defense regulators in Arabidopsis. Using the VIGS vectors these candidate genes will be silenced, or "turned off", in soybean plants that display resistance towards select isolates of ASR. Silenced plants will then be evaluated for a breakdown of resistance by challenging the plants with the pathogen and scoring for the development of disease.
Conserved soybean genes suspected to play a role in resistance towards soybean rust caused by the fungus, Phakopsora pachyrhizi, were targeted for analysis using virus-induced gene silencing in soybean plants carrying the Rpp2 resistance gene. Several genes common to all soybean accession were found to be essential for resistance, including genes that are involved in signaling, secondary metabolism, and gene transcription. Metabolic pathways and gene networks that operate downstream of the genes identified are currently being targeted, as well as other resistance genes that confer resistance towards specific isolates of P. pachyrhizi. This project was monitored by meeting with collaborators semiannually, and by numerous e-mails and telephone calls to plan activities and discuss data.