作者:中科院西北生态环境资源研究所石玉兰、兰州大学生科院安黎哲
标题:Integrated regulation triggered by a cryophyte ω-3 desaturase gene confers multiple-stress tolerance in tobacco
主题:ω-3脂肪酸去饱和酶在植物胁迫耐受中的功能
期刊:Journal of Experimental Botany
影响因子:5.354
检测指标:Ca2+
Ca2+流实验方法:一周龄烟草幼苗,15%PEG6000和200mM NaCl瞬时胁迫处理,检测距离根尖300-400微米的点。
Ca2+流实验测试液成份: 0.05 mM CaCl2, 0.1 mM KCl, 0.1 mM MES, pH6.0
作者:中科院西北生态环境资源研究所石玉兰、兰州大学生科院安黎哲
英文摘要
ω-3 fatty acid desaturases (FADs) are thought to contribute to plant stress tolerance mainly through linolenic acid (C18:3)-induced membrane stabilization, but a comprehensive analysis of their roles in stress adaptation is lacking.
Here, we isolated a microsomal ω-3 FAD gene (CbFAD3) from a cryophyte (Chorispora bungeana) and elucidated its functions in stress tolerance. CbFAD3, exhibiting a high identity to Arabidopsis AtFAD3, was up-regulated by abiotic stresses. Its functionality was verified by heterogonous expression in yeast. Overexpression of CbFAD3 in tobacco constitutively increased C18:3 in both leaves and roots, which maintained the membrane fluidity, and enhanced plant tolerance to cold, drought, and salt stresses.
Notably, the constitutively increased C18:3 induced a sustained activation of plasma membrane Ca2+-ATPase, thereby, changing the stress induced Ca2+ signaling. The reactive oxygen species (ROS) scavenging system, which was positively correlated with the level of C18:3, was also activated in the transgenic lines.
Microarray analysis showed that CbFAD3-overexpressing plants increased the expression of stressresponsive genes, most of which are affected by C18:3, Ca2+, or ROS. Together, CbFAD3 confers tolerance to multiple stresses in tobacco through the C18:3-induced integrated regulation of membrane, Ca2+, ROS, and stress-responsive genes. This is in contrast with previous observations that simply attribute stress tolerance to membrane stabilization.
中文摘要(谷歌机翻译)
ω-3脂肪酸去饱和酶(FADs)被认为主要通过亚麻酸(C18:3)诱导的膜稳定作用促进植物抗逆性,但缺乏对其在胁迫适应中的作用的综合分析。
在这里,我们从冷冻植物(Chorispora bungeana)中分离出微粒体ω-3 FAD基因(CbFAD3),并阐明其在胁迫耐受中的功能。表现出与拟南芥AtFAD3高度同一性的CbFAD3被非生物胁迫上调。其功能通过酵母中的异源表达来验证。烟草中CbFAD3的过量表达在叶和根中组成性地增加了C18:3,这保持了膜的流动性,并增强了植物对冷,干旱和盐胁迫的耐受性。
值得注意的是,组成型增加的C18:3诱导质膜Ca2+-ATPase的持续活化,从而改变应激诱导的Ca2+信号传导。与C18:3水平正相关的活性氧(ROS)清除系统也在转基因系中被激活。
微阵列分析显示过表达CbFAD3的植物增加了应激反应基因的表达,其中大多数受C18:3,Ca2+或ROS的影响。 CbFAD3一起通过C18:3诱导的膜,Ca2+,ROS和应激反应基因的整合调节赋予对烟草中多种胁迫的耐受性。这与先前的观察结果形成对比,之前的观察结果仅仅将压力耐受性归因于膜稳定。
Ca2+ fluxes in root tips treated with 15% PEG or 200 mM NaCl (n=10 ten-day-old seedling roots).