Electron microscopic analysis of the H2O2 accumulation preceding hypersensitive cell death induced by an incompatible strain of Pseudomonas avenae in cultured rice cells
Electron microscopic analysis of the H2O2 accumulation preceding hypersensitive cell death induced by an incompatible strain of Pseudomonas avenae in cultured rice cells
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DOI：
10.1046/j.1464-6722.2001.00087.x
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发表时间：
2002-01-01
影响因子：
4.9
通讯作者：
Isogai, A
中科院分区：
文献类型：
--
作者：
Iwano, M;Che, FS;Isogai, A
用不亲和品系感染培养的水稻细胞会引起寄主的过敏反应，而亲和品系感染不会产生这种反应。在细胞死亡之前，不相容的麦长管霉菌株诱导培养的水稻细胞产生H_2O_2。为了研究过氧化氢产生部位的分布，培养的水稻细胞在被Ce3+溶液感染后孵育。利用配有变压扫描电子显微镜(VP-SEM)的能量色散X射线微区分析(EDX)对反应产物Ce(OH)(2)OOH进行了检测。我们确定过氧化氢的积累是一种局部反应，在细胞表面出现一个圆形区域，仅占感染细胞总数的10%到15%。横切面观察到Ce3+沉积到乳头的质膜、乳头的细胞壁和细菌周围。此外，使用β-1，3-葡聚糖抗体的免疫金电子显微镜显示，在H_2O_2的生成部位也发生了盔状糖的合成。因此，过氧化氢起到了抗菌剂的作用，作为细胞壁交联剂的底物。我们的检测系统采用了装有扫描电子显微镜的EDX系统；该程序将有助于研究氧化猝发在植物-病原菌相互作用中的功能和机制。
Infection of cultured rice cells with an incompatible strain of Pseudomonas avenae induces a hypersensitive reaction of the host, while compatible strain infection produces no such reaction. The induction of H2O2 generation in cultured rice cells by the incompatible strain of P. avenae precedes cell death. To examine the distribution of H2O2 generation sites, cultured rice cells were incubated following infection with a cerium solution. Detection of the reaction product, Ce(OH)(2)OOH, was performed using energy disperse X-ray microanalysis (EDX) fitted with a variable-pressure scanning electron microscope (VP-SEM). We determined that H2O2 accumulation is a local response, appearing as a circular region on the cell surface of only 10% to 15% of the total infected cells. Observation of cross-sections localized cerium deposition to the plasma membranes of papillae, in the cell walls of a papilla and around the bacterium. Furthermore, immuno-gold electron microscopy using antibodies for beta-1,3-glucan suggested that callose synthesis also occurs at the generation site of H2O2. Therefore, H2O2 functions as an antibacterial agent, serving as a substrate for cell wall cross-linking. Our detection system employs an EDX system fitted with SEM; this procedure will be useful to examine the function and mechanism of oxidative bursts in plant-pathogen interactions.