High-affinity salicylic acid-binding protein 2 is required for plant innate immunity and has salicylic acid-stimulated lipase activity
High-affinity salicylic acid-binding protein 2 is required for plant innate immunity and has salicylic acid-stimulated lipase activity
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DOI：
10.1073/pnas.0307162100
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发表时间：
2003-12-23
影响因子：
11.1
通讯作者：
Klessig, DF
中科院分区：
文献类型：
--
作者：
Kumar, D;Klessig, DF
水杨酸（SA）是植物天然免疫信号的重要激素。在这里，我们提出了SA结合蛋白2（SABP 2），烟草蛋白，存在于低丰度和特异性结合SA具有高亲和力的纯化和表征。序列分析预测SABP 2是属于α/β折叠水解酶超家族的脂肪酶。证实了这一预测，重组SABP 2对几种合成底物表现出脂肪酶活性。此外，这种脂肪酶活性受到SA结合的刺激，并可能产生脂质衍生的信号。SABP 2表达的沉默抑制了对烟草花叶病毒的局部抗性，SA诱导的病程相关1（PR-1）基因表达，以及系统获得性抗性的发展。总之，这些结果表明SABP 2是植物免疫应答所需的SA受体。我们进一步提出，SABP 2属于一个大类的配体刺激的水解酶参与应激介导的信号转导。
Salicylic acid (SA) is a critical hormone for signaling innate immunity in plants. Here we present the purification and characterization of SA-binding protein 2 (SABP2), a tobacco protein that is present in low abundance and specifically binds SA with high affinity. Sequence analysis predicted that SABP2 is a lipase belonging to the alpha/beta fold hydrolase super family. Confirming this prediction, recombinant SABP2 exhibited lipase activity against several synthetic substrates. Moreover, this lipase activity was stimulated by SA binding and may generate a lipid-derived signal. Silencing of SABP2 expression suppressed local resistance to tobacco mosaic virus, induction of pathogenesis-related 1 (PR-1) gene expression by SA, and development of systemic acquired resistance. Together, these results suggest that SABP2 is an SA receptor that is required for the plant immune response. We further propose that SABP2 belongs to a large class of ligand-stimulated hydrolases involved in stress hormone-mediated signal transduction.