Systemic acquired resistance (SAR) is a potent innate immunity system in plants that is induced through the salicylic acid-mediated pathway. N-cyanomethyl-2-chloroisonicotinamide (NCI) is able to induce a broad range of disease resistance in tobacco and rice and induces SAR marker gene expression without SA accumulation in tobacco. To clarify the detailed mode of action of NCI, we analyzed its ability to induce defense gene expression and resistance in Arabidopsis mutants that are defective in various defense signaling pathways. Wild-type Arabidopsis treated with NCI exhibited increased expression of several pathogenesis-related genes and enhanced resistance to the bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. NCI induced disease resistance and PR gene expression in NahG transgenic plants, but not in the npr1 mutant. NCI could induce PR gene expression in the etr1-1, ein2-1 and jar1-1 mutants. Thus, NCI activates SAR, independently from ethylene and jasmonic acid, by stimulating the site between SA and NPR1.

中文翻译：

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N-氰基甲基-2-氯异烟酰胺在无水杨酸积累的拟南芥中诱导系统获得性抗药性。

系统获得性抗性（SAR）是植物中有效的先天免疫系统，可通过水杨酸介导的途径诱导。N-氰基甲基-2-氯异烟酰胺（NCI）能够在烟草和水稻中诱导广泛的抗病性，并诱导SAR标记基因表达而在烟草中不积累SA。为了阐明NCI的详细作用方式，我们分析了其在各种防御信号通路中存在缺陷的拟南芥突变体中诱导防御基因表达和抗性的能力。用NCI处理的野生型拟南芥表现出几种发病相关基因的表达增加，并且对细菌病原体丁香假单胞菌pv的抵抗力增强。番茄DC3000。NCI在NahG转基因植物中诱导了抗病性和PR基因表达，但在npr1突变体中却没有。NCI可以在etr1-1，ein2-1和jar1-1突变体中诱导PR基因表达。因此，NCI通过刺激SA和NPR1之间的位点，独立于乙烯和茉莉酸来激活SAR。