Drought is a major environmental factor limiting wheat production worldwide,and developing drought-tolerant cultivars is a central challenge for wheat breeders globally.Therefore,it is important to identify genetic co...Drought is a major environmental factor limiting wheat production worldwide,and developing drought-tolerant cultivars is a central challenge for wheat breeders globally.Therefore,it is important to identify genetic components determining drought tolerance in wheat.In this study,we identified a wheat NAC gene(TaNAC071-A)that is tightly associated with drought tolerance by a genome-wide association study.Knockdown of TaNAC071-A in wheat attenuated plant drought tolerance,whereas its overexpression significantly enhanced drought tolerance through improved water-use efficiency and increased expression of stress-responsive genes.This heightened water-saving mechanism mitigated the yield loss caused by water deficit.Further candidate gene association analysis showed that a 108-bp insertion in the promoter of TaNAC071-A alters its expression level and contributes to variation in drought tolerance among wheat accessions.This insertion contains two MYB cis-regulatory elements(CREs)that can be directly bound by the MYB transcription activator,TaMYBL1,thereby leading to increased TaNAC071-A expression and plant drought tolerance.Importantly,introgression of this 108-bp insertion allele,TaNAC071-AIn-693,into drought-sensitive cultivars could improve their drought tolerance,demonstrating that it is a valuable genetic resource for wheat breeding.Taken together,our findings highlight a major breakthrough in determining the genetic basis underlying phenotypic variation in wheat drought tolerance and showcase the potential of exploiting CRE-containing indels for improving important agronomical traits.展开更多
基金supported by grants from the National Natural Science Foundation of China(31701418 and 32072002)the Natural Science Basic Research Plan in Shaanxi Province of China(2019JCW-18)and the 111 Project from the Ministry of Education of China(B07049).
文摘Drought is a major environmental factor limiting wheat production worldwide,and developing drought-tolerant cultivars is a central challenge for wheat breeders globally.Therefore,it is important to identify genetic components determining drought tolerance in wheat.In this study,we identified a wheat NAC gene(TaNAC071-A)that is tightly associated with drought tolerance by a genome-wide association study.Knockdown of TaNAC071-A in wheat attenuated plant drought tolerance,whereas its overexpression significantly enhanced drought tolerance through improved water-use efficiency and increased expression of stress-responsive genes.This heightened water-saving mechanism mitigated the yield loss caused by water deficit.Further candidate gene association analysis showed that a 108-bp insertion in the promoter of TaNAC071-A alters its expression level and contributes to variation in drought tolerance among wheat accessions.This insertion contains two MYB cis-regulatory elements(CREs)that can be directly bound by the MYB transcription activator,TaMYBL1,thereby leading to increased TaNAC071-A expression and plant drought tolerance.Importantly,introgression of this 108-bp insertion allele,TaNAC071-AIn-693,into drought-sensitive cultivars could improve their drought tolerance,demonstrating that it is a valuable genetic resource for wheat breeding.Taken together,our findings highlight a major breakthrough in determining the genetic basis underlying phenotypic variation in wheat drought tolerance and showcase the potential of exploiting CRE-containing indels for improving important agronomical traits.
