Systemic acquired resistance in Arabidopsis requires salicylic acid but not ethylene
Systemic acquired resistance in Arabidopsis requires salicylic acid but not ethylene
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DOI：
10.1094/mpmi-8-0863
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发表时间：
1995-11-01
影响因子：
3.5
通讯作者：
Ryals, J
中科院分区：
文献类型：
--
作者：
Lawton, K;Weymann, K;Ryals, J
系统获得性抗性（systemic acquired resistance，SAR）是植物对坏死性病原菌侵染的一种可诱导的抗性反应。在诱导的植物中，SAR不仅对诱导的病原菌，而且对其他无关病原菌提供广谱的保护。水杨酸（salicylic acid，SA）和SAR基因的表达在SAR的启动和维持中起着重要作用。我们描述了表达编码水杨酸羟化酶的细菌nahG基因的转基因拟南芥植物的特征，所述水杨酸羟化酶是一种能够代谢SA的酶。该基因的强的组成型表达防止病原体诱导的SA积累和外源SA对SAR的激活，我们表明，在拟南芥SAR可以诱导接种假单胞菌注射器pv。番茄对抗感染的挑战接种霜霉寄生，这种反应是废除在转基因，nahG表达拟南芥，但不是在乙烯不敏感的突变体。这些实验支持SA在SAR中的关键作用，并表明乙烯敏感性不是SAR诱导所必需的。NahG拟南芥植物对于旨在了解SA在植物抗病机制中的作用的未来研究将是重要的。
Systemic acquired resistance (SAR) is an inducible plant response to infection by a necrotizing pathogen, In the induced plant, SAR provides broad-spectrum protection against not only the inducing pathogen, but also against other, unrelated pathogens, Both salicylic acid (SA) and SAR-gene expression have been implicated as playing important roles in the initiation and maintenance of SAR, Here, we describe the characterization of transgenic Arabidopsis plants that express the bacterial nahG gene encoding salicylate hydroxylase, an enzyme that can metabolize SA, Strong, constitutive expression of this gene prevents pathogen-induced accumulation of SA and the activation of SAR by exogenous SA, We show that SAR in Arabidopsis can be induced by inoculation with Pseudomonas syringe pv. tomato against infection by a challenge inoculation with Peronospora parasitica, This response is abolished in transgenic, nahG-expressing Arabidopsis, but not in ethylene-insensitive mutants. These experiments support the critical role of SA in SAR and show that ethylene sensitivity is not required for SAR induction, The NahG Arabidopsis plants will be important for future studies aimed at understanding the role of SA in plant disease resistance mechanisms.