八种食用豆耐热基因家族的比较基因组学解析与耐热性评价指标初探OA

With global warming,high temperature has emerged as one of the principal abiotic stresses constraining the yield and quality of food legumes.To decipher the genetic basis underlying heat tolerance in food legumes,eight representative legume species with high-quality genome assemblies(chickpea,pigeonpea,pea,common bean,adzuki bean,faba bean,mung bean and cowpea)were selected.Through integrated comparative genomics,promoter cis-element analysis,and evolutionary analyses,this study systematically characterized the gene family composition,transcriptional regulation pattern,and inter-specific conservation of heat-tolerance genes(HSF,HSP20,HSP60,HSP70,HSP90),and elucidated the intrinsic associations among these heat-tolerance gene density,GC content,and ecotypic differentiation.The results demonstrated that heat-season legumes(adzuki bean,mung bean,cowpea and pigeonpea)exhibited significantly higher densities of heat-tolerance genes compared to warm-and cool-season legumes.The GC contents of HSF and HSP20 gene families were markedly lower in cool-season legumes,indicating stronger directional selection has acted on GC content in response to thermal stress.The promoter regions of these heat-tolerance genes universally harbored light-,hormone-and stress-responsive cis-elements,whose distribution patterns were highly conserved across the eight legume species.Synteny analyses further revealed that all identified heat-tolerance genes were under purifying selection,reflecting their functional conservation during evolution.Ten HSP20 members with high GC content were prioritized as key candidate genes,and several of these genes were confirmed to be heat-inducible,representing high-priority targets for heat-tolerance breeding.Collectively,this study provides valuable gene resources and reliable molecular markers for food legumes improvement,while offering scientific guidance for rational crop variety deployment and cultivation zoning in the context of global climate change.