Loss-of-function of an Arabidopsis NADPH pyrophosphohydrolase, AtNUDX19, impacts on the pyridine nucleotides status and confers photooxidative stress tolerance.
Loss-of-function of an Arabidopsis NADPH pyrophosphohydrolase, AtNUDX19, impacts on the pyridine nucleotides status and confers photooxidative stress tolerance.
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DOI：
10.1038/srep37432
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发表时间：
2016-11-22
影响因子：
4.6
通讯作者：
Shigeoka S
中科院分区：
文献类型：
--
作者：
Maruta T;Ogawa T;Tsujimura M;Ikemoto K;Yoshida T;Takahashi H;Yoshimura K;Shigeoka S
吡啶核苷酸（如NADP（H））的水平和氧化还原状态调节细胞的氧化还原稳态，这是植物光氧化胁迫反应的关键。然而，人们对它们是如何控制的知之甚少。拟南芥NUDX水解酶AtNUDX 19在体外被鉴定为具有NADPH水解活性，表明该酶是NADPH状态的调节剂。本文中，我们使用AtNUDX 19的功能丧失突变体来检查AtNUDX 19的生理作用。nudx19突变体在正常和强光条件下NADPH水平增加，而NADP+和NAD+水平降低。尽管NADP（H）的氧化还原状态很高，但nudx19突变体对中度光或甲基紫诱导的光氧化胁迫表现出很高的耐受性。这种耐受性可能部分归因于光合作用和抗氧化系统的激活。此外，微阵列分析表明ANUDX 19以负性方式调节水杨酸（SA）反应的作用。事实上，nudx19突变体积累SA，并显示出对激素的高敏感性。我们的研究结果表明，ANUDX 19作为一个NADPH焦磷酸水解酶调节细胞水平和氧化还原状态的吡啶核苷酸和微调光氧化应激反应，通过调节光合作用，抗氧化系统，并可能激素信号。
The levels and redox states of pyridine nucleotides, such as NADP(H), regulate the cellular redox homeostasis, which is crucial for photooxidative stress response in plants. However, how they are controlled is poorly understood. An Arabidopsis Nudix hydrolase, AtNUDX19, was previously identified to have NADPH hydrolytic activity in vitro, suggesting this enzyme to be a regulator of the NADPH status. We herein examined the physiological role of AtNUDX19 using its loss-of-function mutants. NADPH levels were increased in nudx19 mutants under both normal and high light conditions, while NADP+ and NAD+ levels were decreased. Despite the high redox states of NADP(H), nudx19 mutants exhibited high tolerance to moderate light- or methylviologen-induced photooxidative stresses. This tolerance might be partially attributed to the activation of either or both photosynthesis and the antioxidant system. Furthermore, a microarray analysis suggested the role of ANUDX19 in regulation of the salicylic acid (SA) response in a negative manner. Indeed, nudx19 mutants accumulated SA and showed high sensitivity to the hormone. Our findings demonstrate that ANUDX19 acts as an NADPH pyrophosphohydrolase to modulate cellular levels and redox states of pyridine nucleotides and fine-tunes photooxidative stress response through the regulation of photosynthesis, antioxidant system, and possibly hormonal signaling.
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影响因子：
7.4
作者：
HEINEKE, D;RIENS, B;HELDT, HW
通讯作者：
HELDT, HW
DOI：
10.1111/j.2517-6161.1995.tb02031.x
发表时间：
1995-01-01
影响因子：
5.8
作者：
BENJAMINI, Y;HOCHBERG, Y
通讯作者：
HOCHBERG, Y
影响因子：
4.8
作者：
Dunn, CA;O'Handley, SF;Bessman, MJ
通讯作者：
Bessman, MJ
影响因子：
--
作者：
Gunawardana D;Likic VA;Gayler KR
通讯作者：
Gayler KR
影响因子：
11.6
作者：
Kim, Kang-Chang;Lai, Zhibing;Chen, Zhixiang
通讯作者：
Chen, Zhixiang