A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis
A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis
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胡杨中的一种新型 bHLH 转录因子 PebHLH35 通过调节拟南芥的气孔发育、光合作用和生长而赋予其耐旱性
DOI：
10.1016/j.bbrc.2014.05.139
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发表时间：
2014-07-18
影响因子：
3.1
通讯作者：
Yin, Weilun
中科院分区：
文献类型：
--
作者：
Dong, Yan;Wang, Congpeng;Yin, Weilun
植物碱性螺旋-环-螺旋（bHLH）转录因子参与了植物的多种生理过程，包括调节植物对各种非生物胁迫的反应。然而，很少有干旱响应的bHLH家族成员在杨树已被报道。本研究从胡杨中克隆了一个新的bHLH基因（PebHLH 35）。在胡杨中的表达分析表明PebHLH 35受到干旱和脱落酸的诱导。使用PebHLH 35-GFP融合的亚细胞定位研究表明，该蛋白质定位于细胞核。与载体对照植物相比，拟南芥中PebHLH 35的异位过表达导致了更长的主根，更多的叶子，以及在良好浇水条件下更大的叶面积。值得注意的是，PebHLH 35过表达株系表现出对水分亏缺胁迫的耐受性增强。这一发现得到了解剖和生理分析的支持，结果表明气孔密度、气孔开度、蒸腾速率和水分散失减少，叶绿素含量和光合速率较高。我们的研究结果表明，PebHLH 35功能作为一个积极的调节干旱胁迫反应，通过调节气孔密度，气孔开度，光合作用和生长。(C)2014 Elsevier Inc. All rights reserved.
Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth. (C) 2014 Elsevier Inc. All rights reserved.