Overexpression of a bHLH1 Transcription Factor of Pyrus ussuriensis Confers Enhanced Cold Tolerance and Increases Expression of Stress-Responsive Genes.
Overexpression of a bHLH1 Transcription Factor of Pyrus ussuriensis Confers Enhanced Cold Tolerance and Increases Expression of Stress-Responsive Genes.
复制标题
乌苏里梨 bHLH1 转录因子的过表达可增强其耐冷性并增加应激反应基因的表达
DOI：
10.3389/fpls.2016.00441
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发表时间：
2016
影响因子：
5.6
通讯作者：
Zhang SL
中科院分区：
文献类型：
--
作者：
Jin C;Huang XS;Li KQ;Yin H;Li LT;Yao ZH;Zhang SL
碱性螺旋-环-螺旋(BHLH)转录因子参与多种生理生化过程。然而，关于bHLH在耐冷性中的作用的知识仍然知之甚少。本研究从乌苏里梨中分离到一个PubHLH1基因，并对其在耐寒中的功能进行了研究。在低温、盐和脱水条件下，PubHLH1的表达上调，在低温条件下诱导的表达最强。PubHLH1具有反式激活活性，定位于胞核。PubHLH1在转基因烟草中的异位表达增强了烟草对低温胁迫的耐受性。与野生型(WT)相比，转基因品系具有更高的存活率、更高的叶绿素含量、更高的脯氨酸含量、更低的电解质渗漏率和更低的丙二醛含量。此外，在低温胁迫下，与ROS清除、调节和胁迫防御相关的8个基因的转录水平在转基因植株中高于野生型植株。综上所述，这些结果表明，PubHLH1在耐冷性中发挥了关键作用，至少在一定程度上促进了应激反应基因的激活。
The basic helix-loop-helix (bHLH) transcription factors are involved in arrays of physiological and biochemical processes. However, knowledge concerning the functions of bHLHs in cold tolerance remains poorly understood. In this study, a PubHLH1 gene isolated from Pyrus ussuriensis was characterized for its function in cold tolerance. PubHLH1 was upregulated by cold, salt, and dehydration, with the greatest induction under cold conditions. PubHLH1 had the transactivational activity and localized in the nucleus. Ectopic expression of PubHLH1 in transgenic tobacco conferred enhanced tolerance to cold stress. The transgenic lines had higher survival rates, higher chlorophyll, higher proline contents, lower electrolyte leakages and MDA when compared with wild type (WT). In addition, transcript levels of eight genes associated with ROS scavenging, regulation, and stress defense were higher in the transgenic plants relative to the WT under the chilling stress. Taken together, these results demonstrated that PubHLH1 played a key role in cold tolerance and, at least in part, contributed to activation of stress-responsive genes.