Identification and Functional Analyses of Resistance Genes to the Bacterial Pathogen Pst3000 in Rice-Arabidopsis FOX Lines

Abstract

About 13,000 full-length cDNAs of rice were mixed and ligated to an expression vector cassette and introduced into Arabidopsis by Agrobacterium-mediated transformation to generate Rice-Arabidopsis FOX (full-length over-expressor) lines. T2 seedlings from approximately 20,000 FOX lines were screened for resistance to a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000 (Pst3000) by dip inoculation. Finally, 78 resistant lines were selected. The rice cDNAs identified by this procedure are being re-transformed into Arabidopsis and rice for overexpression and further screening to confirm the disease-resistant phenotypes. At present, at least 25 rice cDNAs endowed resistance to Pst3000 to Arabidopsis. One of the genes encoding a novel Receptor-Like Cytoplasmic Kinase, when overexpressed in rice, enabled resistance to both Xanthomonas oryzae, the pathogen that causes Rice Blight and Magnaporthe grisea, the pathogen that causes Rice Blast. Arabidopsis plants overexpressing the same gene that were inoculated with Pst3000 showed an upregulated ET/JA pathway.