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POSTERS: Plant defense response

Generation of Xanthomonas oryzae PthXo1 mutants to gain insight into TALE-dependent Xo1-mediated resistance in rice
Teddy Borland - Colorado State University. Lindsay Triplett- Connecticut Agricultural Experiment Station, Jan Leach- Colorado State University, Alejandra Huerta- Colorado State University

Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, produces Transcription Activator-Like Effectors (TALEs) that activate target gene expression in the plant by binding to gene promoter regions. To circumvent pathogen infection, plants have evolved TALE-associated resistance, including loss of susceptibility, dominant TALE-dependent, and dominant transcription-independent resistance. The recently described Xo1 gene from rice is included the latter category. Little is known about this type of resistance. To understand the mechanism of Xo1, which is independent of gene activation, we created mutations in the surface-exposed amino acids of PthXo1, a TALE which induces resistance in a rice variety carrying Xo1, Carolina Gold. The wild-type alleles triggered resistance when inoculated to Carolina Gold, while the variants lost resistance triggering ability. Our results suggest that the surface exposed amino acids of PthXo1 are critical for triggering Xo1-mediated resistance and give a deeper insight into the mechanism governing non-transcriptional resistance in rice.