Ranjan Ashish, Vadassery Jyothilakshmi, Patel Hitendra Kumar, Pandey Alok, Palaparthi Ramesh, Mithöfer Axel, Sonti Ramesh V
CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, Andhra Pradesh, India.
Funct Integr Genomics. 2015 May;15(3):363-73. doi: 10.1007/s10142-014-0426-8. Epub 2014 Dec 12.
Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, secretes several cell wall degrading enzymes including cellulase (ClsA) and lipase/esterase (LipA). Prior treatment of rice leaves with purified cell wall degrading enzymes such as LipA can confer enhanced resistance against subsequent X. oryzae pv. oryzae infection. To understand LipA-induced rice defense responses, microarray analysis was performed 12 h after enzyme treatment of rice leaves. This reveals that 867 (720 upregulated and 147 downregulated) genes are differentially regulated (≥2-fold). A number of genes involved in defense, stress, signal transduction, and catabolic processes were upregulated while a number of genes involved in photosynthesis and anabolic processes were downregulated. The microarray data also suggested upregulation of jasmonic acid (JA) biosynthetic and JA-responsive genes. Estimation of various phytohormones in LipA-treated rice leaves demonstrated a significant increase in the level of JA-Ile (a known active form of JA) while the levels of other phytohormones were not changed significantly with respect to buffer-treated control. This suggests a role for JA-Ile in cell wall damage induced innate immunity. Furthermore, a comparative analysis of ClsA- and LipA-induced rice genes has identified key rice functions that might be involved in elaboration of damage-associated molecular pattern (DAMP)-induced innate immunity.
水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae）是水稻细菌性条斑病的病原菌，它能分泌多种细胞壁降解酶，包括纤维素酶（ClsA）和脂肪酶/酯酶（LipA）。用纯化的细胞壁降解酶如LipA预先处理水稻叶片，可增强水稻对随后水稻白叶枯病菌感染的抗性。为了解LipA诱导的水稻防御反应，在酶处理水稻叶片12小时后进行了微阵列分析。结果显示，有867个基因（720个上调，147个下调）受到差异调控（≥2倍）。许多参与防御、应激、信号转导和分解代谢过程的基因上调，而许多参与光合作用和合成代谢过程的基因下调。微阵列数据还表明茉莉酸（JA）生物合成和JA响应基因上调。对LipA处理的水稻叶片中各种植物激素的测定表明，JA-Ile（一种已知的JA活性形式）水平显著增加，而其他植物激素的水平与缓冲液处理的对照相比没有显著变化。这表明JA-Ile在细胞壁损伤诱导的先天免疫中发挥作用。此外，对ClsA和LipA诱导的水稻基因的比较分析确定了可能参与损伤相关分子模式（DAMP）诱导的先天免疫的关键水稻功能。
