Two promoter regions confer heat-induced activation of SlDREBA4 in Solanum lycopersicum
Two promoter regions confer heat-induced activation of SlDREBA4 in Solanum lycopersicum
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番茄中两个启动子区域赋予 SlDREBA4 热诱导激活作用
DOI：
10.1016/j.bbrc.2020.01.153
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发表时间：
2020-04-09
影响因子：
3.1
通讯作者：
Zhao, Kai
中科院分区：
文献类型：
--
作者：
Deng, Ming Hua;Lv, Jun Heng;Zhao, Kai
脱水响应元件结合（DREB）转录因子与脱水响应元件（DRE）结合激活下游功能基因的表达，从而提高植物对非生物胁迫如热的抗性。然而，DREB基因在高温下的上游调控机制尚不清楚。从番茄中分离到一个DREBA 4亚家族转录因子（SlDREBA 4），该转录因子具有热响应性和提高番茄的耐热性。在这项研究中，启动子截短实验进行，以验证β-葡萄糖醛酸苷酶（GUS）酶活性和GUS基因表达水平的变化，在转基因植物与不同长度的启动子片段在热下，并确定特定区域的启动子，响应于热。结果表明，GUS报告基因在转全长启动子的Microtom植株的组织中组成型表达，在根、茎、叶的输导组织以及花和果实的萼片中表达量较高。在热处理条件下，转全长启动子基因植株组织中GUS酶活性和GUS基因表达水平均有所提高。启动子缺失分析鉴定了负责启动子对热的响应的两个正调控区（-1095至-730 bp和-162至-38 bp）。这些结果表明，热休克元件（HSE）和MYC识别序列可能在热诱导激活SlDREBA 4启动子协同。(C)2020爱思唯尔公司All rights reserved.
Dehydration-responsive element binding (DREB) transcription factors activate the expression of downstream functional genes in combination with a dehydration-responsive element (DRE), and thereby improve the resistance of plants to abiotic stresses such as heat. However, the upstream regulatory mechanism of DREB genes under heat is unclear. A DREBA4 subfamily transcription factor (SlDREBA4), which is heat-responsive and improves heat resistance, was isolated from Solanum lycopersicum 'Microtom'. In this study, promoter truncation experiments were performed to verify changes in beta-glucuronidase (GUS) enzyme activity and GUS gene expression levels in transgenic plants with different lengths of promoter fragments under heat and to identify specific regions in the promoter that respond to heat. Our results showed that the GUS reporter gene was constitutively expressed in tissues of the full-length promoter transgenic 'Microtom' plants, with higher expression in conducting tissues of root, stem, and leaf, as well as sepals of flowers and fruits. Under heat treatment, GUS enzyme activity and GUS gene expression levels in tissues of the full-length promoter transgenic plants increased. Promoter deletion analysis identified two positive regulatory regions (-1095 to -730 bp and -162 to -38 bp) responsible for the promoter's response to heat. These results indicated that the heat shock element (HSE) and MYC recognition sequences may cooperate in heat-induced activation of SlDREBA4 promoter. (C) 2020 Elsevier Inc. All rights reserved.