Han Fangxu, Wang Peiyi, Chen Xi, Zhao Huanhuan, Zhu Qianya, Song Yitong, Nie Yumeng, Li Yue, Guo Meina, Niu Shihui
National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Hortic Res. 2023 Jun 20;10(8):uhad130. doi: 10.1093/hr/uhad130. eCollection 2023 Aug.
The proper response to various abiotic stresses is essential for plants' survival to overcome their sessile nature, especially for perennial trees with very long-life cycles. However, in conifers, the molecular mechanisms that coordinate multiple abiotic stress responses remain elusive. Here, the transcriptome response to various abiotic stresses like salt, cold, drought, heat shock and osmotic were systematically detected in () seedlings. We found that four transcription factors were commonly induced by all tested stress treatments, while and were highly up-regulated and co-expressed. Unexpectedly, the exogenous hormone treatment assays and the content of the endogenous hormone indicates that the upregulation of and are mediated by ethylene. Time-course assay showed that the treatment by ethylene immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), activated the expression of and within 8 hours. We further confirm that the PtNAC3 can directly bind to the promoter region and form a cascade. Overexpression of enhanced unified abiotic stress tolerance without growth penalty in transgenic and promoted reproductive success under abiotic stress by shortening the lifespan, suggesting it has great potential as a biological tool applied to plant breeding for abiotic stress tolerance. This study provides novel insights into the hub nodes of the abiotic stresses response network as well as the environmental adaptation mechanism in conifers, and provides a potential biofortification tool to enhance plant unified abiotic stress tolerance.
对各种非生物胁迫做出适当反应对于植物克服其固着性以生存至关重要，尤其是对于具有非常长生命周期的多年生树木。然而，在针叶树中，协调多种非生物胁迫反应的分子机制仍然不清楚。在这里，系统地检测了（）幼苗对盐、冷、干旱、热休克和渗透等各种非生物胁迫的转录组反应。我们发现，所有测试的胁迫处理均共同诱导了四种转录因子，而和被高度上调并共同表达。出乎意料的是，外源激素处理试验和内源激素含量表明，和的上调是由乙烯介导的。时间进程分析表明，乙烯直接前体1-氨基环丙烷-1-羧酸（ACC）处理在8小时内激活了和的表达。我们进一步证实，PtNAC3可以直接结合到启动子区域并形成一个级联。在转基因中过表达增强了统一的非生物胁迫耐受性而不影响生长，并通过缩短寿命促进了非生物胁迫下的繁殖成功，这表明它作为一种应用于植物非生物胁迫耐受性育种的生物学工具具有巨大潜力。这项研究为针叶树中非生物胁迫反应网络的枢纽节点以及环境适应机制提供了新的见解，并提供了一种潜在的生物强化工具来增强植物统一的非生物胁迫耐受性。
