Effects of feeding Spodoptera littoralis on lima bean leaves.: III.: Membrane depolarization and involvement of hydrogen peroxide
Effects of feeding Spodoptera littoralis on lima bean leaves.: III.: Membrane depolarization and involvement of hydrogen peroxide
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DOI：
10.1104/pp.105.071993
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发表时间：
2006-03-01
期刊：
影响因子：
7.4
通讯作者：
Boland, W
中科院分区：
文献类型：
--
作者：
Maffei, ME;Mithöfer, A;Boland, W
为了应对草食动物（Spodoptera littoralis）的攻击，利马豆（Phaseolus lunatus）叶片产生的过氧化氢（H2O2）浓度高于机械损伤（MD）叶片。细胞和亚细胞定位分析表明，H2O2主要定位于MD和草食损伤区，并遍布静脉和组织。尽管共聚焦激光扫描显微镜分析也显示H2O2存在于线粒体/过氧化物酶体中，但在面向细胞间隙的海绵状细胞和叶肉细胞的细胞壁中，H2O2优先被发现。HW后超氧化物歧化酶的基因和酶活性的增加与共聚焦激光扫描显微镜的数据一致。在MD处理后，额外施用H2O2促进了瞬时跨膜电位（V-m）去极化，其中aV(m)去极化率高于HW叶片。在表达Ca2（+）感应aequorin系统的转基因大豆（Glycine max）悬浮细胞中，H2O2添加量的增加与细胞质钙([Ca2（+)](cyt)）浓度的升高相关。在MD和HW叶片中，H2O2也触发了[Ca2(+)] cyt的增加，但在添加外源H2O2后，MD诱导的[Ca2(+)] cyt的增加比HW叶片更明显。结果清楚地表明，HW引起的V-m去极化使青豆叶片的膜电位更正，降低了叶片对信号分子的反应能力。
In response to herbivore (Spodoptera littoralis) attack, lima bean (Phaseolus lunatus) leaves produced hydrogen peroxide (H2O2) in concentrations that were higher when compared to mechanically damaged (MD) leaves. Cellular and subcellular localization analyses revealed that H2O2 was mainly localized in MD and herbivore-wounded (HW) zones and spread throughout the veins and tissues. Preferentially, H2O2 was found in cell walls of spongy and mesophyll cells facing intercellular spaces, even though confocal laser scanning microscopy analyses also revealed the presence of H2O2 in mitochondria/peroxisomes. Increased gene and enzyme activations of superoxide dismutase after HW were in agreement with confocal laser scanning microscopy data. After MD, additional application of H2O2 prompted a transient transmembrane potential (V-m) depolarization, with aV(m) depolarization rate that was higher when compared to HW leaves. In transgenic soybean (Glycine max) suspension cells expressing the Ca2(+)-sensing aequorin system, increasing amounts of added H2O2 correlated with a higher cytosolic calcium ([Ca2(+)](cyt)) concentration. In MD and HW leaves, H2O2 also triggered the increase of [Ca2(+)] cyt, but MD-elicited [Ca2(+)](cyt) increase was more pronounced when compared to HW leaves after addition of exogenous H2O2. The results clearly indicate that V-m depolarization caused by HW makes the membrane potential more positive and reduces the ability of lima bean leaves to react to signaling molecules.