Li X, Zhang Y, Clarke J D, Li Y, Dong X
Developmental, Cell, and Molecular Biology Group, Department of Botany, Duke University, Durham, North Carolina 27708-1000, USA.
Cell. 1999 Aug 6;98(3):329-39. doi: 10.1016/s0092-8674(00)81962-5.
Systemic acquired resistance (SAR) is a plant immune response induced after a local infection by necrotizing pathogens. The Arabidopsis NPR1 gene is a positive regulator of SAR, essential for transducing the SAR signal salicylic acid (SA). Mutations in the NPR1 gene abolish the SA-induced expression of pathogenesis-related (PR) genes and resistance to pathogens. To identify additional regulators of SAR, we screened for suppressors of npr1-1. In the npr1-1 background, the sni1 (suppressor of npr1-1, inducible 1) mutant shows near wild-type levels of PR1 expression and resistance to pathogens after induction. Restoration of SAR in npr1-1 by the recessive sni1 mutation indicates that wild-type SNI1 may function as a negative regulator of SAR. We cloned the SNI1 gene and found that it encodes a leucine-rich nuclear protein.
系统获得性抗性（SAR）是植物在被坏死性病原体局部感染后诱导产生的一种免疫反应。拟南芥NPR1基因是SAR的正向调节因子，对于转导SAR信号水杨酸（SA）至关重要。NPR1基因突变会消除SA诱导的病程相关（PR）基因的表达以及对病原体的抗性。为了鉴定SAR的其他调节因子，我们筛选了npr1-1的抑制子。在npr1-1背景下，sni1（npr1-1的抑制子，可诱导1）突变体在诱导后显示出接近野生型水平的PR1表达和对病原体的抗性。隐性sni1突变在npr1-1中恢复SAR表明野生型SNI1可能作为SAR的负调节因子发挥作用。我们克隆了SNI1基因，发现它编码一种富含亮氨酸的核蛋白。
