Cao H, Glazebrook J, Clarke J D, Volko S, Dong X
Department of Botany, Duke University, Durham, North Carolina 27708-1000, USA.
Cell. 1997 Jan 10;88(1):57-63. doi: 10.1016/s0092-8674(00)81858-9.
The Arabidopsis NPR1 gene controls the onset of systemic acquired resistance (SAR), a plant immunity, to a broad spectrum of pathogens that is normally established after a primary exposure to avirulent pathogens. Mutants with defects in NPR1 fail to respond to various SAR-inducing treatments, displaying little expression of pathogenesis-related (PR) genes and exhibiting increased susceptibility to infections. NPR1 was cloned using a map-based approach and was found to encode a novel protein containing ankyrin repeats. The lesion in one npr1 mutant allele disrupted the ankyrin consensus sequence, suggesting that these repeats are important for NPR1 function. Furthermore, transformation of the cloned wild-type NPR1 gene into npr1 mutants not only complemented the mutations, restoring the responsiveness to SAR induction with respect to PR-gene expression and resistance to infections, but also rendered the transgenic plants more resistant to infection by P. syringae in the absence of SAR induction.
拟南芥NPR1基因控制系统获得性抗性（SAR）的起始，系统获得性抗性是一种植物免疫反应，针对多种病原体，通常在初次接触无毒病原体后建立。NPR1有缺陷的突变体对各种诱导SAR的处理无反应，病程相关（PR）基因几乎不表达，且对感染的易感性增加。利用基于图谱的方法克隆了NPR1基因，发现其编码一种含有锚蛋白重复序列的新型蛋白质。一个npr1突变等位基因中的损伤破坏了锚蛋白共有序列，表明这些重复序列对NPR1功能很重要。此外，将克隆的野生型NPR1基因转化到npr1突变体中，不仅弥补了突变，恢复了对SAR诱导的反应能力，包括PR基因表达和对感染的抗性，而且使转基因植物在没有SAR诱导的情况下对丁香假单胞菌感染更具抗性。
