Bacterial lipopolysaccharides induce defense responses associated with programmed cell death in rice cells
Bacterial lipopolysaccharides induce defense responses associated with programmed cell death in rice cells
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DOI：
10.1093/pcp/pcl019
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发表时间：
2006-11-01
影响因子：
4.9
通讯作者：
Shibuya, Naoto
中科院分区：
文献类型：
--
作者：
Desaki, Yoshitake;Miya, Ayako;Shibuya, Naoto
病原体相关分子模式（pathogen-associated molecular pattern，PAMP）识别在植物和动物的天然免疫应答中起着重要的作用。来自革兰氏阴性菌的脂多糖（LPS）是典型的PAMP分子，在植物中具有诱导防御相关反应的作用，包括抑制植物过敏反应、诱导植物防御基因的表达和系统抗性等。然而，关于这些细胞反应背后的精确分子机制的细节，例如参与LPS分子的感知和转导的分子机制，在很大程度上仍然未知。此外，LPS对植物的生物活性迄今仅在双子叶植物中报道，因此没有关于它们在单子叶植物中的功能的信息。在我们目前的研究中，我们报告了各种细菌的LPS制剂，包括植物病原体和非病原体，可以诱导水稻细胞的防御反应，包括活性氧的产生和防御基因的表达。此外，对两种PAMPs（LPS和几丁质寡糖）诱导的基因表达的整体分析也揭示了这些因素诱导的基因应答之间的密切相关性。这表明在其相应受体的下游存在信号级联的收敛。此外，我们表明，LPS诱导的水稻细胞的防御反应与程序性细胞死亡（PCD），这是一个发现，以前没有报道的功能作用，这些分子在植物细胞。有趣的是，在培养的拟南芥细胞中没有检测到LPS诱导的PCD。
PAMP (pathogen-associated molecular pattern) recognition plays an important role during the innate immune response in both plants and animals. Lipopolysaccharides (LPS) derived from Gram-negative bacteria are representative of typical PAMP molecules and have been reported to induce defense-related responses, including the suppression of the hypersensitive response, the expression of defense genes and systemic resistance in plants. However, the details regarding the precise molecular mechanisms underlying these cellular responses, such as the molecular machinery involved in the perception and transduction of LPS molecules, remain largely unknown. Furthermore, the biological activities of LPS on plants have so far been reported only in dicots and no information is thus available regarding their functions in monocots. In our current study, we report that LPS preparations for various becteria, including plant pathogens and non-pathogens, can induce defense responses in rice cells, including reactive oxygen generation and defense gene expression. In addition, global analysis of gene expression induced by two PAMPs, LPS and chitin oligosaccharide, also reveals a close correlation between the gene responses induced by these factors. This indicates that there is a convergence of signaling cascades downstream of their corresponding receptors. Furthermore, we show that the defense responses induced by LPS in the rice cells are associated with programmed cell death (PCD), which is a finding that has not been previously reported for the functional role of these molecules in plant cells. Interestingly, PCD induction by the LPS was not detected in cultured Arabidopsis thaliana cells.