IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Nitric oxide is required for the auxin-induced activation of NADPH-dependent thioredoxin reductase (NTR) and protein denitrosylation during root growth responses in Arabidopsis
Autor/es:
CORREA ARAGUNDE NATALIA; CEJUDO FRANCISCO; LAMATTINA LORENZO
Revista:
ANNALS OF BOTANY
Editorial:
OXFORD UNIV PRESS
Referencias:
Lugar: Oxford; Año: 2015 vol. 116 p. 695 - 702
ISSN:
0305-7364
Resumen:
Auxin is the main plant morphogen controlling root development inplants. In this work it is shown that auxin and nitric oxide (NO) induce the activationof NADPH-dependent thioredoxin reductase (NTR), and that this activity isrequired for root growth responses in Arabidopsisthaliana. Pharmacological andgenetical approaches were used in this work. Arabidopsisthaliana seedlings weretreated with auxin with or without the NTR inhibitors auranofin (ANF)and 1-chloro-2, 4-dinitrobenzene (DCNB). NTR activity, lateral root (LR)formation and S-nitrosothiol content was measured in roots. ProteinS-nitrosylation was analyzed by the biotin switch method in Arabidopsis wildtype and double mutant ntra ntrb. The auxin-mediated inductionof NTR activity is inhibited by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(CPTIO), suggesting that NO is downstream of auxin in this regulatory pathway.The NTR inhibitors ANF and DCNB inhibit auxin-mediated activation of NTR and LRformation. Moreover, ANF and DCNB also inhibit auxin-induced DR5::GUS and BA3::GUSgene expression, suggesting that the auxin signaling pathway is compromisedwithout a full NTR activity. The treatment of roots with ANF and DCNB increasestotal nitrosothiols (SNO) content and protein S-nitrosylation, suggesting arole of the NTR-thioredoxin (Trx)-redox system in protein denitrosylation. Inagreement with these results, the level of S-nitrosylated proteins is increasedin the Arabidopsis double mutant ntrantrb as compared to the wild type. These results support to the notionthat NTR is involved in protein denitrosylation during auxin-mediated rootdevelopment.