Osmotic stress-induced polyamine oxidation mediates defence responses and reduces stress-enhanced grapevine susceptibility to Botrytis cinerea
Osmotic stress-induced polyamine oxidation mediates defence responses and reduces stress-enhanced grapevine susceptibility to Botrytis cinerea
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DOI：
10.1093/jxb/ert351
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发表时间：
2014-01-01
影响因子：
6.9
通讯作者：
Aziz, Aziz
中科院分区：
文献类型：
--
作者：
Hatmi, Saloua;Trotel-Aziz, Patricia;Aziz, Aziz
非生物因子诱导的渗透胁迫可以影响植物的免疫反应和对病原菌侵染的抗性。在这项研究中，聚乙二醇（PEG）和蔗糖诱导的渗透胁迫对多胺（PA）的稳态和基础免疫反应在葡萄藤苗灰霉病菌感染前后的影响进行了测定。药理学方法也被解决，以评估渗透胁迫诱导的PA氧化的防御反应的调节和葡萄藤对B的敏感性的贡献。灰叶在渗透胁迫或病原体感染后，PA稳态与二胺氧化酶（CuAO）和PA氧化酶（PAO）的活性增强以及1，3-二氨基丙烷的产生有关。这些反应包括主要芪类植物抗毒素、白藜芦醇和e-葡萄糖苷的积累和基因转录物的上调，所述基因转录物包括STS（芪合酶）、PR-2（α-1，3-葡聚糖酶）、PR 3 -4c（酸性几丁质酶IV）和PR-5（奇异果甜蛋白样蛋白），以及参与脱落酸生物合成的NCED 2。同时还表明，叶片预先暴露于渗透胁迫，然后接种B。灰葡萄表现为PA积累增强和CuAO和PAO活性减弱。这与感染后植物抗毒素的产生和防御和应激相关基因的转录水平受损以及对B的易感性增强是一致的。灰叶药理实验表明，在渗透胁迫条件下，CuAO和PAO参与PA稳态和防御反应的调节。在干旱胁迫下，CuAO和PAO的特异性抑制强烈减弱了B引发的防御反应的诱导。灰霉病菌感染和增强对病原体的易感性。综上所述，本研究揭示了PA催化剂通过调节葡萄藤在渗透胁迫后和/或B后的免疫应答对抗性状态的贡献。灰霉病
Abiotic factors inducing osmotic stress can influence the plant immune response and resistance to pathogen infections. In this study, the effect of polyethylene glycol (PEG)- and sucrose-induced osmotic stress on polyamine (PA) homeostasis and the basal immune response in grapevine plantlets before and after Botrytis cinerea infection was determined. Pharmacological approaches were also addressed to assess the contribution of osmotic stress-induced PA oxidation to the regulation of defence responses and the susceptibility of grapevine to B. cinerea. Following osmotic stress or pathogen infection, PA homeostasis was linked to enhanced activity of diamine oxidases (CuAO) and PA oxidases (PAO) and the production of 1,3-diaminopropane. These responses paralleled the accumulation of the main stilbenic phytoalexins, resveratrol and e-viniferin and upregulation of gene transcripts including STS (a stilbene synthase), PR-2 (a -1,3-glucanase), PR3-4c (acidic chitinase IV), and PR-5 (a thaumatin-like protein), as well as NCED2 involved in abscisic acid biosynthesis. It was also demonstrated that leaves pre-exposed to osmotic stress and later inoculated with B. cinerea showed enhanced PA accumulation and attenuation of CuAO and PAO activities. This was consistent with the impaired production of phytoalexins and transcript levels of defence- and stress-related genes following infection, and the enhanced susceptibility to B. cinerea. Pharmacological experiments revealed that, under osmotic stress conditions, CuAO and PAO were involved in PA homeostasis and in the regulation of defence responses. Specific inhibition of CuAO and PAO in osmotically stressed leaves strongly attenuated the induction of defence responses triggered by B. cinerea infection and enhanced susceptibility to the pathogen. Taken together, this study reveals a contribution of PA catabolism to the resistance state through modulation of immune response in grapevine following osmotic stress and/or after B. cinerea infection.