Wheat bHLH-type transcription factor gene TabHLH1 is crucial in mediating osmotic stresses tolerance through modulating largely the ABA-associated pathway
Wheat bHLH-type transcription factor gene TabHLH1 is crucial in mediating osmotic stresses tolerance through modulating largely the ABA-associated pathway
复制标题
DOI：
10.1007/s00299-016-2036-5
复制
发表时间：
2016-08
影响因子：
6.2
通讯作者：
Tongren Yang;Sufei Yao;Lin Hao;Yuanyuan Zhao;Wenjing Lu;K. Xiao
中科院分区：
文献类型：
--
作者：
Tongren Yang;Sufei Yao;Lin Hao;Yuanyuan Zhao;Wenjing Lu;K. Xiao
小麦bHLH家族基因TabHLH1对干旱和盐分胁迫反应灵敏，并在很大程度上通过与ABA相关的途径在介导对上述胁迫的耐受性中发挥重要调节作用。在本研究中，我们研究了编码小麦bHLH型转录因子(TF)蛋白的基因TabHLH1在介导植物对渗透胁迫的适应中的作用。TabHLH1蛋白含有一个保守的碱性-螺旋-环-螺旋(BHLH)结构域，与植物的相应结构域相同。在模拟干旱胁迫、盐胁迫和外源脱落酸(ABA)胁迫下，TabHLH1在根和叶中的转录本被诱导。在聚乙二醇模拟干旱胁迫和盐胁迫处理下，与野生型相比，高表达TabHLH1的烟草幼苗表现出更好的生长和渗透胁迫相关性状，表现出生物量的增加和叶片失水率(WLR)的降低。转基因植株在干旱胁迫、盐胁迫和外源ABA胁迫下均表现出促进气孔关闭的作用，在渗透胁迫条件下提高了脯氨酸和可溶性糖的含量，降低了过氧化氢(H_2O_2)的含量，表明TabHLH1介导的渗透调节物质积累和细胞内ROS的平衡参与了干旱胁迫和盐胁迫的耐性。在渗透胁迫和外源ABA条件下，分别编码ABA受体和SnRK2家族激酶基因NtPYL12和NtSAPK2；1在过量表达TabHLH1的品系中表达上调，它们的过度表达改变了植物在干旱和高盐胁迫下的气孔运动、叶片WLR和生长特征，表明这些ABA信号基因是由小麦TabHLH1基因介导的，参与调控植物对模拟干旱和盐分胁迫的反应。我们的研究表明，TabHLH1基因在植物对渗透胁迫的耐受性中发挥关键作用，主要是通过依赖于ABA的途径。
Key messageWheat bHLH family geneTabHLH1is responsive to drought and salt stresses, and it acts as one crucial regulator in mediating tolerance to aforementioned stresses largely through an ABA-associated pathway.AbstractOsmotic stresses are adverse factors for plant growth and crop productivity. In this study, we characterized TabHLH1, a gene encoding wheat bHLH-type transcription factor (TF) protein, in mediating plant adaptation to osmotic stresses. TabHLH1 protein contains a conserved basic-helix-loop-helix (bHLH) domain shared by its plant counterparts. Upon PEG-simulated drought stress, salt stress, and exogenous abscisic acid (ABA), the TabHLH1 transcripts in roots and leaves were induced. Under PEG-simulated drought stress and salt stress treatments, the tobacco seedlings with TabHLH1 overexpression exhibited improved growth and osmotic stress-associated traits, showing increased biomass and reduced leaf water loss rate (WLR) relative to wild type (WT). The transgenic lines also possessed promoted stomata closure under drought stress, salt stress, and exogenous ABA and increased proline and soluble sugar contents and reduced hydrogen peroxide (H2O2) amount under osmotic stress conditions, indicating that TabHLH1-mediated osmolyte accumulation and cellular ROS homeostasis contributed to the drought stress and salt stress tolerance. NtPYL12 and NtSAPK2;1, the genes encoding ABA receptor and SnRK2 family kinase, respectively, showed up-regulated expression in lines overexpressing TabHLH1 under osmotic stress and exogenous ABA conditions; overexpression of them conferred plants modified stomata movement, leaf WLR, and growth feature under drought and high salinity, suggesting that these ABA-signaling genes are mediated by wheat TabHLH1 gene and involved in regulating plant responses to simulated drought and salt stresses. Our investigation indicates that the TabHLH1 gene plays critical roles in plant tolerance to osmotic stresses largely through an ABA-dependent pathway.