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Loss-of-function of an Arabidopsis NADPH pyrophosphohydrolase, AtNUDX19, impacts on the pyridine nucleotides status and confers photooxidative stress tolerance.
- Source :
-
Scientific reports [Sci Rep] 2016 Nov 22; Vol. 6, pp. 37432. Date of Electronic Publication: 2016 Nov 22. - Publication Year :
- 2016
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Abstract
- 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 <superscript>+</superscript> and NAD <superscript>+</superscript> 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.
- Subjects :
- Antioxidants metabolism
Arabidopsis physiology
Arabidopsis radiation effects
Cell Nucleus metabolism
Cell Nucleus radiation effects
Gene Expression Regulation, Plant radiation effects
Oxidation-Reduction radiation effects
Photosynthesis radiation effects
Phylogeny
Pyrophosphatases chemistry
Pyrophosphatases genetics
Salicylic Acid metabolism
Nudix Hydrolases
Adaptation, Physiological radiation effects
Arabidopsis enzymology
Light
Loss of Function Mutation genetics
Nucleotides metabolism
Oxidative Stress radiation effects
Pyridines metabolism
Pyrophosphatases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 2045-2322
- Volume :
- 6
- Database :
- MEDLINE
- Journal :
- Scientific reports
- Publication Type :
- Academic Journal
- Accession number :
- 27874073
- Full Text :
- https://doi.org/10.1038/srep37432