小麦耐盐基因TaAT1的优异等位变异挖掘OA

TaAT1 is a key gene encoding an atypical G protein γ subunit(Gγ)that is involved in salt stress tolerance regulation in wheat.To identify its superior allelic variations,we constructed a mutant library of the wheat cultivar Jing 411 using ethyl methanesulfonate(EMS),γ-rays,and high-energy carbon ion irradiation,with wild-type Jing 411 as the control.Through salt stress evaluation at the seedling stage,mutation site validation,and transcriptome analysis,we obtained the mutant line je0088 with significantly improved salt tolerance.This mutant exhibited substantially enhanced salt tolerance compared with the wild type,and its main agronomic traits including plant architecture and growth duration remained stable.Sequencing verification confirmed that the mutant carried only a premature stop mutation(c.285G>A)in TaAT1-7A,suggesting that this site is a key functional locus regulating salt tolerance.Transcriptomic GO enrichment analysis revealed that differentially expressed genes(DEGs)in the aboveground tissues of the mutant were mainly enriched in the photosystem II and carbon fixation,whereas DEGs in roots were enriched in transmembrane transport activity and microtubule motor activity.KEGG analysis showed that aboveground DEGs were concentrated in photosynthesis and carbon fixation pathways,while root DEGs were mainly involved in phenylpropanoid biosynthesis,starch and sucrose metabolism,and glutathione metabolism.This study provides new gene targets and elite germplasm resources for molecular breeding of salt-tolerant wheat,and lays a foundation for dissecting the molecular mechanism of TaAT1-mediated salt stress tolerance.