Nitric oxide increases mitochondrial respiration in a cGMP-dependent manner in the callus from Arabidopsis thaliana

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• 作者：Xiaomin Wang ; Jisheng Li ; Jie Liu ; Wenliang He ; Yurong Bi
• 关键词：Alternative pathway ; Arabidopsis ; cGMP ; Cytochrome pathway ; Mitochondria ; Nitric oxide
• 刊名：Nitric Oxide
• 出版年：2010
• 出版时间：1 November 2010
• 年：2010
• 卷：23
• 期：3
• 页码：242-250
• 全文大小：961 K

文摘

Nitric oxide (NO) acts as a key molecule in many physiological processes in plants. In this study, the roles of NO in mitochondrial respiration were investigated in the calli from wild-type Arabidopsis and NO associated 1 mutant (Atnoa1) which has a reduced endogenous NO level. Long-term exposure of wild-type Arabidopsis callus to sodium nitroprusside (SNP) increased mitochondrial respiration in both cytochrome and alternative pathways. In Atnoa1 callus, the capacity of both the cytochrome pathway and the alternative pathway was lower than that in wild-type callus. Further study indicated that NO enhanced the transcript abundance of genes encoding mitochondrial respiration-chain proteins as well as the protein expression of the NADH-ubiquinone reductase 75 kDa subunit and the alternative oxidase 1/2 in wild-type and Atnoa1 calli. 2-Phenyl-4,4,5,5-tetremethy-limidazolinone-1-oxyl-3-oxide (PTIO), a NO scavenger, inhibited the effects of NO in both calli. Co-incubation of callus with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a guanylate cyclase inhibitor, also abolished NO effects. The membrane-permeable cGMP analog 8Br-cGMP mimicked NO effects. Moreover, the alternative pathway showed a higher sensitivity to the cellular cGMP changes than the cytochrome pathway did in gene transcription, protein expression and O₂ consumption. Taken together, NO could enhance mitochondrial respiration in both cytochrome and alternative pathways in a cGMP-dependent manner in Arabidopsis.