State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
Plant Physiol. 2010 Apr;152(4):2222-31. doi: 10.1104/pp.109.151803. Epub 2010 Feb 17.
Pathogen-associated molecular patterns (PAMPs) trigger plant defenses when perceived by surface-localized immune receptors. PAMP-triggered immunity (PTI) plays a vital role in the resistance of plants to numerous potential pathogens. MicroRNA (miRNA) biogenesis is known to be important for PTI, but miRNA species involved in this process have not been fully explored. Here we show that the Arabidopsis (Arabidopsis thaliana) miRNA effector protein, Argonaute1 (AGO1), is required for a number of PTI responses including PAMP-induced callose deposition, gene expression, and seedling growth inhibition. Deep sequencing of AGO1-bound small RNAs led to the identification of a number of miRNAs that are up- or down-regulated by flg22, a well-studied PAMP. Overexpression of selected miRNAs in stable transgenic plants demonstrated that miR160a positively regulate PAMP-induced callose deposition, whereas miR398b and miR773 negatively regulate PAMP-induced callose deposition and disease resistance to bacteria, suggesting a complexity of the miRNA regulation in plant innate immunity.
病原体相关分子模式（PAMPs）被表面定位的免疫受体感知时，会触发植物防御。病原体触发的免疫（PTI）在植物对许多潜在病原体的抗性中起着至关重要的作用。已知 microRNA（miRNA）生物发生对于 PTI 很重要，但参与该过程的 miRNA 种类尚未得到充分探索。在这里，我们表明拟南芥（Arabidopsis thaliana）miRNA 效应蛋白 Argonaute1（AGO1）对于许多 PTI 反应是必需的，包括 PAMP 诱导的胼胝质沉积、基因表达和幼苗生长抑制。AGO1 结合的小 RNA 的深度测序导致鉴定了许多 miRNA，这些 miRNA 被 flg22 上调或下调，flg22 是一种研究充分的 PAMP。在稳定的转基因植物中过表达选定的 miRNA 表明，miR160a 正向调节 PAMP 诱导的胼胝质沉积，而 miR398b 和 miR773 负向调节 PAMP 诱导的胼胝质沉积和对细菌的抗病性，表明 miRNA 在植物先天免疫中的调控具有复杂性。
