Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. SAR requires the signal molecule salicylic acid (SA) and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. Much progress has been made recently in elucidating the mechanism of SAR. Using the model plant Arabidopsis, it was discovered that the isochorismate pathway is the major source of SA during SAR. In response to SA, the positive regulator protein NPR1 moves to the nucleus where it interacts with TGA transcription factors to induce defense gene expression, thus activating SAR. Exciting new data suggest that the mobile signal for SAR might be a lipid molecule. We discuss the molecular and genetic data that have contributed to our understanding of SAR and present a model describing the sequence of events leading from initial infection to the induction of defense genes.

中文翻译：

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全身获得性抵抗。

系统获得性抗药性（SAR）是诱导防御的机制，可赋予针对广泛范围的微生物的长期保护。SAR需要信号分子水杨酸（SA），并与致病相关蛋白的积累相关，而这些蛋白被认为有助于抵抗。最近在阐明SAR机理方面已经取得了很大进展。使用模型植物拟南芥，发现等渗途径是SAR期间SA的主要来源。响应SA，正调节蛋白NPR1移至细胞核，与TGA转录因子相互作用以诱导防御基因表达，从而激活SAR。令人兴奋的新数据表明，SAR的移动信号可能是脂质分子。