Involvement of nitrate reductase (NR) in osmotic stress-induced NO generation of Arabidopsis thaliana L. roots
Involvement of nitrate reductase (NR) in osmotic stress-induced NO generation of Arabidopsis thaliana L. roots
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DOI：
10.1016/j.jplph.2009.08.013
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发表时间：
2010-01-01
影响因子：
4.3
通讯作者：
Erdei, Laszlo
中科院分区：
文献类型：
--
作者：
Kolbert, Zsuzsanna;Ortega, Leandro;Erdei, Laszlo
一氧化氮（NO）无疑是一种潜在的信号分子，参与多种发育过程和应激反应。尽管我们对NO在生理和应激反应中的作用有广泛的了解，但这种气体分子的来源仍然没有得到解决。本研究的目的是调查潜在的作用，硝酸还原酶（NR）作为来源的NO积累的野生型和NR缺陷型nia 1，nia 2突变体拟南芥植物根系在渗透胁迫条件下的聚乙二醇（PEG 6000）处理诱导。在野生型和NR-缺陷植物中，渗透胁迫的效果检测到初生根（PR）长度的减少。我们发现，渗透胁迫诱导的侧根（LR）的起始在野生型，但不是在NR-突变体植物。高水平的NO的形成发生在Col-1植物的根作为PEG处理的效果。哺乳动物一氧化氮合酶（NOS）抑制剂N-G-单甲基-L-精氨酸（L-NMMA）对LR的启动和NO的产生没有影响，而硝酸还原酶（NR）抑制剂钨酸盐则抑制了渗透胁迫诱导的后期NO的积累，并轻微降低了LR的发展。在nia 1、nia 2根中，PEG处理诱导了NO的产生，但随后抑制了NO的产生。我们的结论是，PEG诱导的NO生成的第一阶段是不依赖于NOS样或NR活性。这也表明，在渗透胁迫诱导的NO形成的后期阶段，根中NR的活性是必需的。(C)2009年Elsevier GmbH。All rights reserved.
Nitric oxide (NO) is undoubtedly a potential signal molecule in diverse developmental processes and stress responses. Despite our extensive knowledge about the role of NO in physiological and stress responses, the source of this gaseous molecule is still unresolved. The aim of this study was to investigate the potential role of nitrate reductase (NR) as the source of NO accumulation in the root system of wild-type and NR-deficient nia1, nia2 mutant Arabidopsis plants under osmotic stress conditions induced by a polyethylene glycol (PEG 6000) treatment. Reduction of primary root (PR) length was detected as the effect of osmotic stress in wild-type and NR-deficient plants. We found that osmotic stress-induced lateral root (LR) initiation in wild-type, but not in NR-mutant plants. High levels of NO formation occurred in roots of Col-1 plants as the effect of PEG treatment. The mammalian nitric oxide synthase (NOS) inhibitor N-G-monomethyl-L-arginine (L-NMMA) had no effect on LR initiation or NO generation, while tungstate, an NR inhibitor, inhibited the later phase of osmotic stress-induced NO accumulation and slightly decreased the LR development. In nia1, nia2 roots, the PEG treatment induced the first phase of NO production, but later NO production was inhibited. We conclude that the first phase of PEG-induced NO generation is not dependent on NOS-like or NR activity. it is also suggested that the activity of NR in roots is required for the later phase of osmotic stress-induced NO formation. (C) 2009 Elsevier GmbH. All rights reserved.