作物学报2025，Vol.51Issue(4)：873-887,15.DOI:10.3724/SP.J.1006.2025.41068
大麦HvMYB2分子特性及响应干旱胁迫的功能分析
Molecular characteristics and functional analysis of HvMYB2 in response to drought stress in barley
摘要
Abstract
Drought is one of the most critical environmental stresses affecting global agricultural production,severely impairing crop growth and yield.Identifying drought-resistant genes in wild barley holds significant potential for the utilization of arid and semi-arid lands in northwest China.This study focused on the molecular characterization of the HvMYB2 gene and its functional role under drought stress.A 912 bp coding sequence(CDS)of HvMYB2 was amplified from the drought-tolerant wild barley EC_S1,encoding a protein of 303 amino acids.Conserved structure analysis revealed that HvMYB2 is an R2R3-type MYB tran-scription factor containing two HTH_MYB domains,and it was predicted to localize in the nucleus.Phylogenetic analysis showed that HvMYB2 shares the highest homology(87.5%)with wheat PIMP1.Expression pattern analysis indicated that HvMYB2 is most highly expressed in the shoots at the seedling stage.Under drought stress,HvMYB2 expression was significantly upregulated in the drought-tolerant wild barley EC_S1.Arabidopsis thaliana plants overexpressing HvMYB2 exhibited enhanced drought tolerance,characterized by higher relative water content,increased chlorophyll a and b levels,and reduced relative electrical con-ductivity.Additionally,these plants displayed lower stomatal conductance under drought conditions compared to wild-type plants.Conversely,silencing HvMYB2 in barley significantly reduced drought tolerance,resulting in greater water loss,increased cell damage,and higher stomatal conductance.These results suggest that HvMYB2 positively regulates drought tolerance in barley by modulating stomatal closure.Protein interaction predictions indicated that HvMYB2 may form a complex with the transcription factors HvMYB27 and HvMYB29 to regulate downstream gene expression.Promoter analysis of HvMYB2 revealed the presence of multiple drought-responsive and hormone-regulated elements.Notably,the insertion of a 181 bp specific fragment in the HvMYB2 promoter of wild barley significantly enhanced its transcription under drought conditions,potentially contributing to the strong drought tolerance observed in EC_S1.These findings provide new insights into the role of HvMYB2 in plant drought tolerance mechanisms and offer a valuable genetic resource for improving drought tolerance in barley.关键词
野生大麦/MYB转录因子/干旱胁迫/基因克隆/VIGS沉默Key words
wild barley/MYB transcription factor/drought stress/gene cloning/VIGS引用本文复制引用
王林,陈晓雨,张文梦龙,汪思琦,程冰云,程靖秋,潘锐,张文英..大麦HvMYB2分子特性及响应干旱胁迫的功能分析[J].作物学报,2025,51(4):873-887,15.基金项目
本研究由国家自然科学基金面上项目(32372052)和长江大学大学生创新创业项目(Yz2023206)资助. This study was supported by the National Natural Science Foundation of China(32372052)and the College Students'Innovative Entrepre-neurial Training Plan Program in Yangtze University(Yz2023206). （32372052）
