Role of nitric oxide in hydrogen peroxide-dependent induction of abiotic stress tolerance by brassinosteroids in cucumber
Role of nitric oxide in hydrogen peroxide-dependent induction of abiotic stress tolerance by brassinosteroids in cucumber
复制标题
一氧化氮在黄瓜油菜素类固醇过氧化氢依赖性诱导非生物胁迫耐受性中的作用
DOI：
10.1111/j.1365-3040.2010.02248.x
复制
发表时间：
2011-02-01
影响因子：
7.3
通讯作者：
Yu, Jing-Quan
中科院分区：
文献类型：
--
作者：
Cui, Jin-Xia;Zhou, Yan-Hong;Yu, Jing-Quan
油菜素类固醇(BRs)可以通过触发黄瓜叶片中作为信号分子的过氧化氢的产生来诱导植物对各种非生物胁迫的耐受。一氧化氮(NO)是否也起信号作用，如果是，在BR诱导的应激耐受中，NO和H_2O_2之间的关系尚不清楚。检测NO和H_2O_2在BR诱导耐受中的作用。激光共聚焦显微镜和qRT-PCR分别检测NO积聚和防御相关基因的转录本。24-表油菜素内酯(EBR)处理后，NO含量升高，BR生物合成受到抑制，NO含量降低。NADPH氧化酶抑制剂和活性氧清除剂可阻断EBR诱导的NO生成。另一方面，EBR诱导的H_2O_2生成对NO清除剂或NO生成抑制剂不敏感。清除或抑制NO的产生可抑制EBR诱导的对光氧化和冷胁迫的耐受性，并部分阻断EBR诱导的几种抗氧化酶的表达和活性。另一方面，外源NO前体的预处理既提高了胁迫耐受性，又增加了抗氧化酶的表达。这些结果有力地表明，NO在BR依赖的H_2O_2诱导植物抗逆性中起着重要作用。
Brassinosteroids (BRs) can induce plant tolerance to a variety of abiotic stresses by triggering the generation of H2O2 as a signalling molecule in cucumber leaves. Whether nitric oxide (NO) also plays a signalling role and, if so, what is the relationship between NO and H2O2 in BR-induced stress tolerance are unknown. Involvement of NO and H2O2 in BR-induced tolerance was examined. NO accumulation and defence related gene transcripts were monitored by confocal laser-scanning microscopy and qRT-PCR, respectively. NO content was elevated after treatment with 24-epibrassinolide (EBR) and reduced with the inhibition of BR biosynthesis. EBR-induced NO production was blocked by pre-treatment with inhibitor of NADPH oxidase and a reactive oxygen species scavenger. On the other hand, EBR-induced H2O2 generation was not sensitive to NO scavenger or inhibitor of NO production. Scavenging or inhibition of NO production inhibited EBR-induced tolerance to photo-oxidative and cold stress and partly blocked EBR-induced expression and activities of several antioxidant enzymes. Pre-treatment of the exogenous NO precursor, on the other hand, led to both increased stress tolerance and increased expression of antioxidant enzymes. These results strongly suggest that NO plays an important role in H2O2-dependent induction of plant stress tolerance by BR.