Elicitor-induced activation of phospholipases plays an important role for the induction of defense responses in suspension-cultured rice cells.
Elicitor-induced activation of phospholipases plays an important role for the induction of defense responses in suspension-cultured rice cells.
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DOI：
10.1093/pcp/pci065
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发表时间：
2005-04
影响因子：
4.9
通讯作者：
T. Yamaguchi;E. Minami;J. Ueki;N. Shibuya
中科院分区：
文献类型：
--
作者：
T. Yamaguchi;E. Minami;J. Ueki;N. Shibuya
N - 乙酰壳寡糖激发子诱导水稻细胞产生的活性氧（ROS）呈双相性，这与磷脂酶C（PLC）和磷脂酶D（PLD）的激活有关。在ROS产生的第一阶段，观察到这两种酶均被激活，但在第二阶段反应中，仅PLD的激活较为明显。PLD的激活与其向细胞膜的募集有关。这些磷脂酶的酶促产物，二酰甘油（DG）和磷脂酸（PA），自身即可诱导ROS的产生。此外，添加这些脂质可弥补环己酰亚胺对ROS产生第二阶段的抑制作用，这表明在ROS产生的第二阶段涉及PLD或相关蛋白质的合成。在无激发子存在的情况下，DG和PA也能诱导激发子响应基因的表达。它们自身虽不能诱导植物抗毒素的生物合成，但能显著增强激发子诱导的植物抗毒素积累。此外，1 - 丁醇对PLD的抑制作用会抑制激发子诱导的植物抗毒素积累，这表明PLD及其反应产物PA参与了植物抗毒素生物合成的诱导过程。这些结果表明，磷脂信号传导，尤其是PLD及其产物PA介导的信号传导，在植物防御反应中具有重要意义。
Biphasic generation of reactive oxygen species (ROS) induced by N-acetylchitooligosaccharide elicitor in rice cells was associated with the activation of phopholipase C (PLC) and phospholipase D (PLD). The activation of both enzymes was observed for the first phase of ROS generation, but only the activation of PLD was evident for the second response. Activation of PLD was associated with its recruitment to the membrane. Enzymatic products of these phospholipases, diacylglycerol (DG) and phosphatidic acid (PA), could induce ROS generation by themselves. Moreover, the addition of these lipids compensated the inhibition of the second phase of ROS generation by cycloheximide, indicating the involvement of the synthesis of PLD or related proteins in the second phase of ROS generation. DG and PA also induced the expression of elicitor-responsive genes in the absence of the elicitor. They could not induce phytoalexin biosynthesis by themselves but greatly enhanced the elicitor-induced phytoalexin accumulation. Further, the inhibition of PLD by 1-butanol inhibited the elicitor-induced phytoalexin accumulation, indicating the involvement of PLD and its reaction product, PA, in the induction of phytoalexin biosynthesis. These results indicated the importance of phospholipid signaling, especially by PLD and its product PA, in plant defense responses.