OsNCED5, a 9-cis-epoxycarotenoid dioxygenase gene, regulates salt and water stress tolerance and leaf senescence in rice
OsNCED5, a 9-cis-epoxycarotenoid dioxygenase gene, regulates salt and water stress tolerance and leaf senescence in rice
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DOI：
10.1016/j.plantsci.2019.110188
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发表时间：
2019-10-01
期刊：
影响因子：
5.2
通讯作者：
Liang, Manzhong
中科院分区：
文献类型：
--
作者：
Huang, Yuan;Jiao, Yang;Liang, Manzhong
9-顺式环氧类胡萝卜素双加氧酶（NCED）是脱落酸（ABA）生物合成的限速酶。然而，NCED5调控植物发育和非生物胁迫耐受性的分子机制仍不清楚，特别是在水稻中。在这里，我们证明了水稻NCED基因，OsNCED5，在我们测试的所有组织中表达，并通过暴露于盐胁迫，水分胁迫和黑暗诱导。突变分析表明，nced5突变体降低了ABA水平，降低了对盐和水分胁迫的耐受性，延缓了叶片衰老。然而，OsNCED5过表达增加ABA水平，增强对胁迫的耐受性，并加速叶片衰老。转录本分析表明，OsNCED5调控ABA依赖的非生物胁迫和衰老相关基因的表达。此外，在拟南芥中测试的OsNCED5的异位表达改变了植物的大小和叶片形态，并延迟了种子萌发和开花时间。因此，OsNCED5可能通过调控ABA的生物合成来调节植物的发育和抗逆性。这些发现有助于我们理解NCED调控植物发育和不同作物对非生物胁迫反应的分子机制。
9-cis-epoxycarotenoid dioxygenase (NCED) is a rate-limiting enzyme for abscisic acid (ABA) biosynthesis. However, the molecular mechanisms of NCED5 that modulate plant development and abiotic stress tolerance are still unclear, particular in rice. Here, we demonstrate that a rice NCED gene, OsNCED5, was expressed in all tissues we tested, and was induced by exposure to salt stress, water stress, and darkness. Mutational analysis showed that nced5 mutants reduced ABA level and decreased tolerance to salt and water stress and delayed leaf senescence. However, OsNCED5 overexpression increased ABA level, enhanced tolerance to the stresses, and accelerated leaf senescence. Transcript analysis showed that OsNCED5 regulated ABA-dependent abiotic stress and senescence-related gene expression. Additionally, ectopic expression of OsNCED5 tested in Arabidopsis thaliana altered plant size and leaf morphology and delayed seed germination and flowering time. Thus, OsNCED5 may regulate plant development and stress resistance through control of ABA biosynthesis. These findings contribute to our understanding of the molecular mechanisms by which NCED regulates plant development and responses to abiotic stress in different crop species.