Bulked Segregant RNA-Seq Reveals Distinct Expression Profiling in Chinese Wheat Cultivar Jimai 23 Responding to Powdery Mildew.

Wheat powdery mildew, caused byBlumeria graminisf. sp.tritici(Bgt), is one of the most destructive fungal diseases threatening global wheat production. Host resistance is well known to be the most efficient method to control this disease. However, the molecular mechanism of wheat powdery mildew resistance (Pm) is still unclear. To analyze the molecular mechanism ofPm, we used the resistant wheat cultivar Jimai 23 to investigate its potential resistance components and profiled its expression in response to powdery mildew infection using bulked segregant RNA-Seq (BSR-Seq). We showed that thePmof Jimai 23 was provided by a single dominant gene, tentatively designatedPmJM23, and assigned it to the documentedPm2region of chromosome 5DS. 3,816 consistently different SNPs were called between resistant and susceptible parents and the bulked pools derived from the combinations between the resistant parent Jimai23 and the susceptible parent Tainong18. 58 of the SNPs were assigned to the candidate region ofPmJM23. Subsequently, 3,803 differentially expressed genes (DEGs) between parents and bulks were analyzed by GO, COG and KEGG pathway enrichment. The temporal expression patterns of associated genes followingBgtinoculation were further determined by RT-qPCR. Expression of six disease-related genes was investigated duringBgtinfection and might serve as valuable genetic resources for the improvement of durable resistance toBgt.