CYTOCHROME C MODULATES PLANT GROWTHRATE AND THE ACTIVITY OF THE GIBBERELLINPATHWAY

RACCA S; GONZALEZ DH; WELCHEN E

Congreso; LII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB); 2016

We studied the effect of reducing the levels of the mitochondrial electron carrier cytochrome c (CYTc) in plants. Double knockdownmutants in both genes encoding CYTc in Arabidopsis thaliana show a severe delay in vegetative growth and developmental rate.Additionally, CYTc deficiency causes starch and glucose accumulation indicating that these plants accumulate reserves instead ofusing them for growth. Treatment of mutants with the gibberellin GA47abolishes the developmental delay, suggesting that it isassociated to GA deficiency. Transcriptional analyses show that the expression of several genes involved in GA homeostasis is alteredin mutant plants, while the levels of DELLA proteins, repressors of GA signaling, are increased. In addition, plants with increasedCYTc levels show accelerated growth and reduced levels of DELLA proteins. We propose that hormone regulation of growth iscoupled to the activity of components involved in mitochondrial energy metabolism.