Nitric oxide regulates mitochondrial biogenesis in plants

Abstract

The site of nitric oxide (NO) production in mitochondrial cytochrome c oxidase and the role of NO in mitochondrial biogenesis are not known in plants. By imposing osmotic stress and recovery on Arabidopsis seedlings we investigated the site of NO production and its role in mitochondrial biogenesis. Osmotic stress reduced growth and mitochondrial number while increasing NO production. During the recovery phase the mitochondrial number increased and this increase was higher in wild type and the high NO‐producing Pgb1 silencing line in comparison to the NO‐deficient nitrate reductase double mutant (nia1/nia2). Application of nitrite stimulated NO production and mitochondrial number in the nia1/nia2 mutant. Osmotic stress induced COX6b−3 and COA6‐L genes encoding subunits of COX. The mutants cox6b‐3 and coa6‐l were impaired both in NO production and mitochondrial number during stress to recovery suggesting the involvement of these subunits in nitrite‐dependent NO production. Transcripts encoding the mitochondrial protein import machinery showed reduced expression in cox6b‐3 and coa6‐l mutants. Finally, COX6b‐3 and COA6‐L interacted with the VQ27 motif‐containing protein in the presence of NO. The vq27 mutant was impaired in mitochondrial biogenesis. Our results suggest the involvement of COX derived NO in mitochondrial biogenesis.

Large-Scale Identification and Characterization Analysis of VQ Family Genes in Plants, Especially Gymnosperms

“…Similarly, monocotyledonous and dicotyledonous plants have their own independent and intersecting branches (Figure S6), which is consistent with previous research [3]. Interestingly, among widely expressed VQ genes, we found that four genes (GbVQ3, GbVQ12, GbVQ33, and GbVQ34) in Ginkgo biloba, one gene (TcVQ2) in Taxus chinensis, and three genes (PtVQ29, PtVQ30, and PtVQ58) in Pinus tabulaeformis were clustered with AtVQ14, AtVQ9, and AtVQ5 (Figure S6), which were reported as influencing seed development, mediating salinity stress responses, and regulating plant defense, respectively [5,22,26]; three genes (GbVQ26, GbVQ27, and GbVQ29) found in Ginkgo biloba, three genes (TcVQ13, TcVQ14, and TcVQ15) in Taxus chinensis, and three genes (PtVQ37, PtVQ38, and PtVQ39) in Pinus tabulaeformis were clustered with AtVQ22, AtVQ27, and AtVQ28 (Figure S6), which are related to plant defense and growth [18,48,49]. Among them, GbVQ29, TcVQ13, and PtVQ38 are the only VQ genes in the collinear block shared by these gymnosperms, which indicates that these genes have a very conservative, important role and status in seed plants.…”