小麦抗白粉病基因TaMlo的优异等位变异挖掘OA

To mine superior allelic variation of the powdery mildew resistance gene TaMlo in wheat,a mutant library of Jing411 generated by ethyl methanesulfonate(EMS),γ-ray and C-ion beam irradiation was used as experimental materials,with wild type Jing411 as the control.Three mutants-designated je0140,je0322 and je0220-with significantly enhanced powdery mildew resistance were screened through inoculation identification,mutation site verification and transcriptome sequencing analysis.The results showed that the powdery mildew resistance of the three mutants was significantly higher than that of the wild-type control,while important agronomic traits such as plant architecture and growth period were stable.Mutation site verification revealed that all three mutants carried a missense mutation on chromosome 4B,while other detected mutations were located in non-coding regions,indicating that this locus on the B genome is a key functional site conferring powdery mildew resistance.GO enrichment analysis showed that differentially expressed genes in je0140 was enriched in calcium signaling and circadian rhythm pathways,those in je0322 were enriched in energy metabolism and redox regulation pathways,and those in je0220 were enriched in cell wall remodeling and material transport pathways.KEGG pathway analysis indicated that differentially expressed genes were mainly enriched in disease resistance-related pathways such as phenylpropanoid biosynthesis,plant-pathogen interaction,plant hormone signal transduction and MAPK signaling.This study provides new molecular targets and elite germplasm resources for wheat powdery mildew resistance breeding,and also lays a theoretical foundation for in-depth analysis of TaMlo gene function.