Overexpression of AHL20 Negatively Regulates Defenses in Arabidopsis
Overexpression of AHL20 Negatively Regulates Defenses in Arabidopsis
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DOI：
10.1111/j.1744-7909.2010.00969.x
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发表时间：
2010-09-01
影响因子：
11.4
通讯作者：
Feng, Na
中科院分区：
文献类型：
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作者：
Lu, Haibin;Zou, Yan;Feng, Na
植物能够识别入侵的病原微生物，并通过感知病原体相关分子模式(PAMPs)来激活天然免疫反应。PAMP触发的免疫(PTI)对于植物对潜在病原菌的抗性是至关重要的。尽管PTI被激活的机制已经被深入研究，但植物到底是如何防止不受调控的免疫反应的还不太清楚。在这里，我们提供了AHL20，一个含有DNA结合蛋白的AT挂钩蛋白，负向调节PTI的证据。稳定转基因AHL20的过表达抑制了PAMP诱导的拟南芥中NHO1和FRK1的表达。同样，亲缘关系密切的家族成员AHL19、AHL15和AHL27在原生质体中的瞬时表达也阻断了PAMP诱导的基因表达。AHL20高表达植株对丁香假单胞菌强毒力表现出较强的敏感性。这些结果表明，AHL蛋白在植物免疫中起着重要作用。
Plants are equipped to recognize invading pathogenic microbes and activate innate immune responses by sensing pathogen-associated molecular patterns (PAMPs). PAMP-triggered immunity (PTI) is critical for plant resistance to potential pathogens. Although the mechanism by which PTI is activated has been intensively studied, exactly how plants prevent unregulated immune responses is less well understood. Here we provide evidence that AHL20, an AT-hook containing DNA-binding protein, negatively regulates PTI. Overexpression of AHL20 as a stable transgene suppressed PAMP-induced NHO1 and FRK1 expression in Arabidopsis plants. Similarly, transient expression of the closely related family members AHL19, AHL15, and AHL27 in protoplasts also blocked PAMP-induced gene expression. The AHL20 overexpression plants displayed greater susceptibility to virulent Pseudomonas syringae bacteria. These results indicate that AHL proteins play an important role in plant immunity.