1a.Objectives (from AD-416):
Develop soybean with broad resistance to all pests and pathogens using genetics and functional genomics. Special emphasis will be placed upon resistance to fungi and nematodes, as these are the main pests of soybean.
1b.Approach (from AD-416):
There is extensive knowledge of plant defense pathways leading to resistance to a multitude of pathogens, including fungi and bacteria, in the model system Arabidopsis. Especially important are the genes leading to the synthesis of jasmonate-related compounds, salicylic acid, ethylene and genes involve in the hypersensitive response. We propose to move the knowledge of disease resistance obtained using Arabidopsis into soybean to develop soybean with superior resistance to pests and pathogens, especially to fungi and nematodes, the primary biotic causes of yield loss. Over a multi-year period, we propose to identify more than fifty soybean genes homologous to Arabidopsis genes important to defense through comparison of DNA sequences and translated protein sequences, complementation of Arabidopsis mutants, and silencing of the homologous soybean genes.
We cloned more than thirty Arabidopsis genes with functions identified through mutant analysis that are important to the response of Arabidopsis to pathogens. We transformed soybean roots of composite plants with gene over-expression constructs. Two of the Arabidopsis genes decreased the number of mature cyst nematode females by 50% or more and one also decreased the number of galls formed by the root-knot nematode by more than 50%.