Identifying candidate genes for the resistance to sharp eyespot in wheat by meta-QTL analysis and gene expression
摘要
Wheat sharp eyespot is a soil-borne fungal disease and causes severe yield reduction in wheat worldwide. Identifying candidate genes and enhancing the resistance to sharp eyespot in wheat varieties are effective ways to control the disease. In this study, we performed meta-analysis to identify 7 high potential MQTL by integrating 80 initial QTL related to wheat sharp eyespot resistance. The average confidence interval (CI) of these MQTL was refined to 7.29 cM, representing a 1.95-fold increase in resolution compared to the initial QTL. Notably, the genetic distance of MQTL5 was condensed to less than 1 cM. A total of 275 high confidence annotated genes were obtained as candidate genes within these 7 MQTL by bioinformatic interrogation. GO and KEGG analyses revealed that these genes enriched most significantly in the plant-pathogen interaction pathway. Based on the analysis of qRT-PCR, we further screened out 6 candidate genes showed differential expression between resistant (CI12633 and Niavt14) and susceptible (Yu49 and EM23) cultivars after pathogen inoculation. These candidates include genes encoding an endo-1,3-β-glucanase-like protein (TraesCS6B02G138300), a calmodulin-binding family protein (TraesCS6B02G137500), a short-chain dehydrogenase reductase (TraesCS2D02G058400), two NBS-LRR proteins (TraesCS7D02G106100 and TraesCS7D02G106200), and a kinase family protein (TraesCS2B02G537200). All candidate genes were upregulated in resistant cultivars after Rhizoctonia cerealis infection. Our findings provide a principled foundation for marker-assisted selection and the elucidation of molecular resistance mechanisms in wheat defense against R. cerealis.