共 54 条
Alternative Oxidase Alleviates Mitochondrial Oxidative Stress during Limited Nitrate Reduction in Arabidopsis thaliana
被引:1
作者:
Otomaru, Daisuke
[1
]
Ooi, Natsumi
[1
,2
]
Monden, Kota
[1
]
Suzuki, Takamasa
[3
]
Noguchi, Ko
[4
]
Nakagawa, Tsuyoshi
[1
]
Hachiya, Takushi
[1
]
机构:
[1] Shimane Univ, Interdisciplinary Ctr Sci Res, Dept Mol & Funct Genom, 1060 Nishikawatsu Cho, Matsue, Shimane 6908504, Japan
[2] Nara Inst Sci & Technol, Div Biol Sci, 8916-5 Takayama, Ikoma, Nara 6300192, Japan
[3] Chubu Univ, Coll Biosci & Biotechnol, 1200 Matsumoto Cho, Kasugai, Aichi 4878501, Japan
[4] Tokyo Univ Pharm & Life Sci, Dept Life Sci, 1432-1 Horinouchi, Hachioji, Tokyo 1920392, Japan
基金:
日本学术振兴会;
关键词:
alternative oxidase;
mitochondrial dysfunction stimulon;
nitrate reduction;
oxidative stress;
NAC TRANSCRIPTION FACTOR;
RESPIRATORY-CHAIN;
GENE-EXPRESSION;
IDENTIFICATION;
ASSIMILATION;
PATHWAYS;
GROWTH;
LONG;
ROOT;
PHOTOSYNTHESIS;
D O I:
10.3390/biom14080989
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
The conversion of nitrate to ammonium, i.e., nitrate reduction, is a major consumer of reductants in plants. Previous studies have reported that the mitochondrial alternative oxidase (AOX) is upregulated under limited nitrate reduction conditions, including no/low nitrate or when ammonium is the sole nitrogen (N) source. Electron transfer from ubiquinone to AOX bypasses the proton-pumping complexes III and IV, thereby consuming reductants efficiently. Thus, upregulated AOX under limited nitrate reduction may dissipate excessive reductants and thereby attenuate oxidative stress. Nevertheless, so far there is no firm evidence for this hypothesis due to the lack of experimental systems to analyze the direct relationship between nitrate reduction and AOX. We therefore developed a novel culturing system for A. thaliana that manipulates shoot activities of nitrate reduction and AOX separately without causing N starvation, ammonium toxicity, or lack of nitrate signal. Using shoots processed with this system, we examined genome-wide gene expression and growth to better understand the relationship between AOX and nitrate reduction. The results showed that, only when nitrate reduction was limited, AOX deficiency significantly upregulated genes involved in mitochondrial oxidative stress, reductant shuttles, and non-phosphorylating bypasses of the respiratory chain, and inhibited growth. Thus, we conclude that AOX alleviates mitochondrial oxidative stress and sustains plant growth under limited nitrate reduction.
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