INVESTIGADORES
GRAS Diana Ester
artículos
Título:
Arabidopsis thaliana SURFEIT1-like genes link mitochondrial function to early plant development and hormonal growth responses
Autor/es:
GRAS DE; MANSILLA, N; RODRIGUEZ C; WELCHEN E; GONZALEZ, DH
Revista:
PLANT JOURNAL
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2020
ISSN:
0960-7412
Resumen:
Mutations in SURFEIT1 (SURF1) genes affect cytochrome c oxidase (COX) levels in different prokaryotic and eukaryotic organisms. In this work, we describe that Arabidopsis thaliana has two genes that potentially encode SURF1 proteins, due to a duplication that took place in Brassicaceae. Both genes encode mitochondrial proteins and mutation of one of them, AtSURF1a, causes embryonic lethality. Mutation of AtSURF1b, instead, causes defects in hypocotyl elongation under conditions that stimulate growth, such as low light intensity, increased ambient temperature and incubation with glucose. Mutants in AtSURF1b show reduced expression of the auxin reporter DR5:GUS and increased levels of the gibberellin reporter GFP-RGA, suggesting that auxin and gibberellin homeostasis are affected. In agreement with this, the growth defects caused by AtSURF1b mutation can be overcome by treatment with indole-3-acetic acid and gibberellin A3, and also by increasing the expression of the auxin biosynthesis gene YUC8 or the transcription factor PIF4, which shows lower abundance in AtSURF1b deficient plants. Mutants in AtSURF1b display lower COX levels, higher alternative oxidase and superoxide levels, and increased expression of genes that respond to mitochondrial dysfunction. Decreased hypocotyl growth and DR5:GUS expression can be reversed by treatment with reduced glutathione, suggesting that redox changes, probably related to mitochondrial dysfunction, are responsible for the effect of AtSURF1b deficiency on hormone responses. The results indicate that changes in AtSURF1b affect mitochondrial function and reactive oxygen species production, which, in turn, impinges on a growth regulatory circuit that involves auxin, gibberellins and the transcription factor PIF4.