Enhanced expression of EsWAX1 improves drought tolerance with increased accumulation of cuticular wax and ascorbic acid in transgenic Arabidopsis.
Enhanced expression of EsWAX1 improves drought tolerance with increased accumulation of cuticular wax and ascorbic acid in transgenic Arabidopsis.
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DOI：
10.1016/j.plaphy.2013.11.028
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Lin Zhu;Jiansheng Guo;Jian Zhu;Cheng Zhou
中科院分区：
文献类型：
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作者：
Lin Zhu;Jiansheng Guo;Jian Zhu;Cheng Zhou
干旱可以激活植物的多种胁迫反应，例如气孔关闭、角质层蜡和抗坏血酸（AsA）的积累，这些反应与耐旱性的提高有关。本研究从Eutrema salsugineum中分离和鉴定了一个新的MYB基因EsWAX1。EsWAX1包含一个全长1068 bp的开放阅读框（ORF），编码355个氨基酸。干旱胁迫和 ABA 处理可以快速诱导 EsWAX1 的转录水平，表明 EsWAX1 可能作为响应干旱胁迫的正调节因子。 EsWAX1 的异位表达通过调节几个蜡相关基因（如 CER1、KCS2 和 KCR1）的表达来增加角质层蜡的积累。扫描电子显微镜进一步揭示了转基因拟南芥植物叶片近轴表面上更高密度的蜡晶体结构。此外，在 EsWAX1 过表达品系中，几个 AsA 生物合成基因（VTC1、GLDH 和 MIOX4）的表达显着上调，这些转基因植物的总 AsA 含量比 WT 植物高约 23-27%。然而，EsWAX1的高水平表达严重扰乱了植物的正常生长发育。为了减少 EsWAX1 过度表达对植物生长的负面影响，我们产生了由胁迫诱导的 RD29A 启动子驱动表达 EsWAX1 的转基因拟南芥植物。我们的数据表明RD29A::EsWAX1转基因植物比野生型植物具有更强的干旱胁迫耐受性。总而言之，EsWAX1基因是一种潜在的调节因子，可用于通过基因操作提高植物的耐旱性。
Drought can activate several stress responses in plants, such as stomatal closure, accumulation of cuticular wax and ascorbic acid (AsA), which have been correlated with improvement of drought tolerance. In this study, a novel MYB gene, designed asEsWAX1, was isolated and characterized from Eutrema salsugineum.EsWAX1contained a full-length open reading frame (ORF) of 1068 bp, which encoding 355 amino acids. Transcript levels ofEsWAX1were quickly inducible by drought stress and ABA treatment, indicating thatEsWAX1may act as a positive regulator in response to drought stress. Ectopic expression ofEsWAX1increased accumulation of cuticular wax via modulating the expression of several wax-related genes, such asCER1, KCS2andKCR1. Scanning electron microscopy further revealed higher densities of wax crystalline structures on the adaxial surfaces of leaves in transgenic Arabidopsis plants. In addition, the expression of several AsA biosynthetic genes (VTC1, GLDHandMIOX4) was significantly up-regulated inEsWAX1-overexpressing lines and these transgenic plants have approximately 23–27% more total AsA content than WT plants. However, the high-level expression ofEsWAX1severely disrupted plant normal growth and development. To reduce negative effects ofEsWAX1over-expression on plant growth, we generated transgenicArabidopsisplants expressingEsWAX1driven by the stress-inducibleRD29Apromoter. Our data indicated theRD29A::EsWAX1transgenic plants had greater tolerance to drought stress than wild-type plants. Taken together, theEsWAX1gene is a potential regulator that may be utilized to improve plant drought tolerance by genetic manipulation.