Localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells to Pseudomonas syringae pv phaseolicola
Localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells to Pseudomonas syringae pv phaseolicola
复制标题
DOI：
10.1105/tpc.9.2.209
复制
发表时间：
1997-02-01
期刊：
影响因子：
11.6
通讯作者：
Mansfield, JW
中科院分区：
文献类型：
--
作者：
Bestwick, CS;Brown, IR;Mansfield, JW
活性氧过氧化氢（H2O2）通过与氯化铈反应产生电子致密的过氢氧化铈沉积物而被细胞化学检测到。在未接种的生菜叶子中，H2O2 通常存在于木质部导管的次生增厚壁内。接种 Pseudomonas syringae pv Phaseolicola 的野生型细胞引起快速过敏反应 (HR)，在此过程中，在附着细菌附近的植物细胞壁中发现 H2O2 高度局部积累。定量分析表明，在这个非宿主抗性的例子中，经历 HR 的细胞接种后 5 至 8 小时之间发生了长时间的 H2O2 爆发。对野生型菌株和非致病性 hrpD 突变体的反应中发生的细胞壁改变和乳头沉积与 H2O2 的强烈染色无关，除非反应细胞正在进行 HR。用于分解 H2O2 的过氧化氢酶处理几乎完全消除了染色，但 3-氨基-1,2,4-三唑（过氧化氢酶抑制剂）并不影响检测到的 H2O2 的分布模式。抑制植物过氧化物酶（使用氰化钾和叠氮化钠）比抑制中性粒细胞样 NADPH 氧化酶（使用二亚苯基碘鎓氯化物）更能减少 H2O2 的产生。结果表明，CeCl3 与过量的 H2O2 发生反应，而过量的 H2O2 在细胞壁中发生的交联反应中不会快速代谢；在植物-细菌相互作用的早期阶段如此过量的H2O2仅在HR期间产生。 H2O2 的高度局部积累与其作为抗菌剂的直接作用以及作为细菌附着部位局部膜损伤的原因一致。
The active oxygen species hydrogen peroxide (H2O2) was detected cytochemically by its reaction with cerium chloride to produce electron-dense deposits of cerium perhydroxides. In uninoculated lettuce leaves, H2O2 was typically present within the secondary thickened walls of xylem vessels. inoculation with wild-type cells of Pseudomonas syringae pv phaseolicola caused a rapid hypersensitive reaction (HR) during which highly localized accumulation of H2O2 was found in plant cell walls adjacent to attached bacteria. Quantitative analysis indicated a prolonged burst of H2O2 occurring between 5 to 8 hr after inoculation in cells undergoing the HR during this example of non-host resistance. Cell wall alterations and papilla deposition, which occurred in response to both the wild-type strain and a nonpathogenic hrpD mutant, were not associated with intense staining for H2O2, unless the responding cell was undergoing the HR. Catalase treatment to decompose H2O2 almost entirely eliminated staining, but 3-amino-1,2,4-triazole (catalase inhibitor) did not affect the pattern of distribution of H2O2 detected. H2O2 production was reduced more by the inhibition of plant peroxidases (with potassium cyanide and sodium azide) than by inhibition of neutrophil-like NADPH oxidase (with diphenylene iodonium chloride). Results suggest that CeCl3 reacts with excess H2O2 that is not rapidly metabolized during cross-linking reactions occurring in cell walls; such an excess of H2O2 in the early stages of the plant-bacterium interaction was only produced during the HR. The highly localized accumulation of H2O2 is consistent with its direct role as an antimicrobial agent and as the cause of localized membrane damage at sites of bacterial attachment.