Modulation of mitochondrial activity by S-nitrosoglutathione reductase in Arabidopsis thaliana transgenic cell lines

Autor(es)

Frungillo, Lucas ^[1] ; Palamim de Oliveira, Jusceley Fatima ^[1] ; Saviani, Elzira Elisabeth ^[1] ; Oliveira, Halley Caixeta ^[1] ; Carmen Martinez, M. ^[2] ; Salgado, Ione ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Inst Biol, Dept Biol Vegetal, BR-13083970 Campinas, SP - Brazil

^[2] Univ Autonoma Barcelona, Fac Biociencies, Dept Bioquim & Biol Mol, E-08193 Barcelona - Spain

• Tipo de documento: Artigo Científico
• Fonte: BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS; v. 1827, n. 3, p. 239-247, MAR 2013.
• Citações Web of Science: 19

Resumo

The enzyme S-nitrosoglutathione reductase (GSNOR) has an important role in the metabolism of S-nitrosothiols (SNO) and, consequently, in the modulation of nitric oxide (NO)-mediated processes. Although the mitochondrial electron transport chain is an important target of NO, the role of GSNOR in the functionality of plant mitochondria has not been addressed. Here, we measured SNO content and NO emission in Arabidopsis thaliana cell suspension cultures of wild-type (WT) and GSNOR overexpressing (GSNOR(OE)) or antisense (GSNOR(AS)) transgenic lines, grown under optimal conditions and under nutritional stress. Respiratory activity of isolated mitochondria and expression of genes encoding for mitochondrial proteins were also analyzed. Under optimal growth conditions, GSNOR(OE) had the lowest SNO and NO levels and GSNOR(AS) the highest, as expected by the GSNO-consuming activity of GSNOR. Under stress, this pattern was reversed. Analysis of oxygen uptake by isolated mitochondria showed that complex I and external NADH dehydrogenase activities were inhibited in GSNOR(OE) cells grown under nutritional stress. Moreover, GSNOR(OE) could not increase alternative oxidase (AOX) activity under nutritional stress. GSNOR(AS) showed constitutively high activity of external NADH dehydrogenase, and maintained the activity of the uncoupling protein (UCP) under stress. The alterations observed in mitochondrial protein activities were not strictly correlated to changes in gene expression, but instead seemed to be related with the SNO/NO content, suggesting a post-transcriptional regulation. Overall, our results highlight the importance of GSNOR in modulating SNO and NO homeostasis as well mitochondrial functionality, both under normal and adverse conditions in A. thaliana cells. (C) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/11636-5 - Sinalização do óxido nítrico (NO) na resposta de defesa de plantas ao ataque de patógenos: análise da expressão gênica, produção de compostos secundários e bioenergética mitocondrial
• Beneficiário: Ione Salgado
• Linha de fomento: Auxílio à Pesquisa - Regular