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Oral: Plant Resistance


Understanding quantitative disease resistance in rice: defense response gene regulation and promoter patterns
B. TONNESSEN (1), R. Mauleon (2), N. Alexandrov (2), J. Leach (3) (1) Colorado State University, U.S.A.; (2) International Rice Research Institute, Philippines; (3) Colorado State University, U.S.A.

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The potential yield of rice worldwide is reduced by one third due to disease. The extensive work in breeding rice varieties that harbor resistance genes has helped to mitigate this damage. The method is effective, but the selective pressure of a single host resistance gene can be overcome after only a few generations. Enhancing the expression of basal defense response (DR) genes that are activated against a broad spectrum of pathogens could be a more sustainable approach to breeding for resilience. DR gene promoters can affect timing and intensity of expression, and rice varieties with good basal resistance have been shown to contain polymorphisms that are beneficial in the activation of the defense response. Recently, the genomes of a diverse panel of 3000 rice varieties were sequenced. This information, along with transcriptomic analyses of resistant interactions, were utilized in this study to uncover the genome-wide patterns in DR gene promoters. These patterns are potential cis-elements, and DR gene-specific combinations of these elements in multiple loci infers their functionality in fine-tuning regulation during a resistant host-pathogen interaction. These results could refine marker assisted breeding for a stable, broad spectrum resistance.