The bHLH family member ZmPTF1 regulates drought tolerance in maize by promoting root development and abscisic acid synthesis
The bHLH family member ZmPTF1 regulates drought tolerance in maize by promoting root development and abscisic acid synthesis
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bHLH家族成员ZmPTF1通过促进根系发育和脱落酸合成来调节玉米的耐旱性
DOI：
10.1093/jxb/erz307
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发表时间：
2019-10-01
影响因子：
6.9
通讯作者：
Zhang, Juren
中科院分区：
文献类型：
--
作者：
Li, Zhaoxia;Liu, Can;Zhang, Juren
干旱胁迫是限制玉米生产的最重要的环境胁迫。ZmPTF1是一种磷饥饿诱导的碱性螺旋-环-螺旋(BHLH)转录因子，与玉米的根发育和耐低磷有关。本研究以玉米ZmPTF1高表达品系和突变体为材料，研究了ZmPTF1的表达、耐旱性及其机制。ZmPTF1被发现是根发育、ABA合成、信号转导和抗旱性的正向调节因子。ZmPTF1还与9-cis-EPOXYCAROTENOID双加氧酶(NCED)、C-重复结合因子(CBF4)、ATAF2/NAC081、NAC30等转录因子启动子中的G-box元件结合，并作为这些基因表达的正调控因子。显著上调的NCED导致脱落酸(ABA)合成增加，并激活ABA信号通路。上调的转录因子层次化地调节与根发育、逆境反应和转录调节修饰有关的基因的表达。根系的改善、ABA含量的增加以及ABA、CBF4、ATAF2和NAC30介导的胁迫反应增强了ZmPTF1高表达品系的耐旱性，而突变体则表现出相反的趋势。这项研究描述了一个用于转基因育种的有用基因，并帮助我们了解bHLH蛋白在植物根发育和逆境反应中的作用。
Drought stress is the most important environmental stress limiting maize production. ZmPTF1, a phosphate starvation-induced basic helix-loop-helix (bHLH) transcription factor, contributes to root development and low-phosphate tolerance in maize. Here, ZmPTF1 expression, drought tolerance, and the underlying mechanisms were studied by using maize ZmPTF1 overexpression lines and mutants. ZmPTF1 was found to be a positive regulator of root development, ABA synthesis, signalling pathways, and drought tolerance. ZmPTF1 was also found to bind to the G-box element within the promoter of 9-cis-epoxycarotenoid dioxygenase (NCED), C-repeat-binding factor (CBF4), ATAF2/NAC081, NAC30, and other transcription factors, and to act as a positive regulator of the expression of those genes. The dramatically upregulated NCEDs led to increased abscisic acid (ABA) synthesis and activation of the ABA signalling pathway. The up-regulated transcription factors hierarchically regulate the expression of genes involved in root development, stress responses, and modifications of transcriptional regulation. The improved root system, increased ABA content, and activated ABA-, CBF4-, ATAF2-, and NAC30-mediated stress responses increased the drought tolerance of the ZmPTF1 overexpression lines, while the mutants showed opposite trends. This study describes a useful gene for transgenic breeding and helps us understand the role of a bHLH protein in plant root development and stress responses.