Subcellular localization of H2O2 in plants. H2O2 accumulation in papillae and hypersensitive response during the barley-powdery mildew interaction
Subcellular localization of H2O2 in plants. H2O2 accumulation in papillae and hypersensitive response during the barley-powdery mildew interaction
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DOI：
10.1046/j.1365-313x.1997.11061187.x
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发表时间：
1997-06-01
期刊：
影响因子：
7.2
通讯作者：
Collinge, DB
中科院分区：
文献类型：
--
作者：
ThordalChristensen, H;Zhang, ZG;Collinge, DB
活性氧（AOS）被认为在植物中具有重要作用，特别是在植物与病原体的相互作用中。它们被认为参与信号转导、细胞壁强化、超敏反应（HR）和植物抗菌素的产生，并具有直接的抗菌作用。由于目前的方法不足以在完整的植物组织中定位AOS，因此大多数研究都是使用细胞悬浮培养/激发子系统进行的。在过氧化物酶存在的情况下，3,3-二氨基联苯胺（DAB）一旦与H2O2接触，就会发生瞬间的局部聚合，研究发现，通过让叶片吸收这种底物，可以在亚细胞水平上对H2O2进行体内和原位检测。该方法成功地检测了与白粉病真菌相互作用的大麦叶片发育中的乳突和周围的晕（细胞壁附着）以及整个细胞中的H2O2。由此可见，接种后6 h可在原代胚管下的表皮细胞壁中检测到H2O2，接种后15 h可在附着胞下检测到H2O2。接种后15 h可最早观察到与HR相关的表皮细胞H2O2， H2O2首先出现在下面的叶肉细胞附着区，最终在整个表皮细胞中检测到H2O2。此外，观察到乳头和HR细胞中的蛋白质是交联的，这一过程被认为是由H2O2推动的。这种交联加强了对抗，可能有助于阻止病原体。
Active oxygen species (AOS) are believed to have important roles in plants in general and in plant-pathogen interactions in particular. They are believed to be involved in signal transduction, cell wall reinforcement, hypersensitive response (HR) and phytoalexin production, and to have direct antimicrobial effects. Since current methods are inadequate for localizing AOS in intact plant tissue, most studies have been conducted using cell suspension culture/elicitors systems. 3,3-diaminobenzidine (DAB) polymerizes instantly and locally as soon as it comes into contact with H2O2 in the presence of peroxidase, and it was found that, by allowing the leaf to take up this substrate, in-vivo and in-situ detection of H2O2 can be made at subcellular levels. This method was successfully used to detect H2O2 in developing papillae and surrounding haloes (cell wall appositions) and whole cells of barley leaves interacting with the powdery mildew fungus. Thus, H2O2 can be detected in the epidermal cell wall subjacent to the primary germ tube from 6 h after inoculation, and subjacent to the appressorium from 15 h. The earliest time point for observation of H2O2 in relation to epidermal cells undergoing HR is 15 h after inoculation, first appearing in the zones of attachment to the mesophyll cells underneath, and eventually in the entire epidermal cell. Furthermore, it was observed that proteins in papillae and HR cells are cross-linked, a process believed to be fuelled by H2O2. This cross-linking reinforces the apposition, presumably assisting the arrest of the pathogen.