Identification of a candidate rice blast resistance gene, Pior4(t), in an introgression line of Oryza rufipogon using CRISPR/Cas9-mediated genome editing

Le résumé fourni par la source

Resistance breeding for rice blast is an economic strategy for protecting rice crops against this disease. Genes with nucleotide-binding site leucine-rich repeat (NBS-LRR) structures are known to contribute to disease resistance. Here, we identified a candidate resistance gene, named Pior4(t), associated with leaf and panicle blasts in an introgression line carrying the chromosome 4 segment of wild rice (Oryza rufipogon Griff.) backcrossed with the cultivar ‘Nipponbare’ (Oryza sativa L.). Mapping analysis based on leaf blast severity confirmed that Pior4(t) was localized in the 177-kb NBS-LRR cluster region. To identify the Pior4(t) sequence, mutant lines were generated by knocking out a candidate NBS-LRR gene in a homozygous line carrying Pior4(t), M18, using CRISPR/Cas9-mediated genome editing. Leaf blast resistance was lost in the mutant lines lacking the corresponding Os04g0620950 N-terminal sequence of the M18 line. The result suggested that the counterpart NBS-LRR gene in the M18 line is involved in resistance to leaf blast. Pior4(t) showed homology to Pi63 in the resistant cultivar ‘Kahei’, and an NBS-LRR gene in the resistant cultivar ‘Mine-haruka’ carrying Pi39(t). These results suggest that the NBS-LRR gene is a candidate gene of Pior4(t) and is present on the long arm of chromosome 4.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.