INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Modifications on root mitochondria during dark-induced senescence
BARTOLI, CARLOS GUILLERMO; FANELLO, DIEGO; GUIAMET, JUAN JOSÉ
Congreso; 8th International Conference for Plant Mitochondria Biology; 2013
Senescence traditionally refers to degradative processes in leaves and mainly in chloroplast. Studies about modifications in plant root metabolism and mitochondrial associated activities during senescence are scarce. The experiments of this work are attempted to study mitochondria modifications during plant development. Arabidopsis thaliana plants with a targeting signal to mitochondria fused to YFP were used. This plant were cultivated in a hydroponic system at 22°C, 150 μmole m-2 s-1 (PPFD) and de 8/16 h light/darkness photoperiod. Seven weeks-old plants were induced to senesces under darkness for 10 days. Roots of darkened plant showed a detention of growth whereas control plants under light continued growing. Respiration rate was 70% less in roots of darkened plants compared with those of control plants. Epiflorescence and confocal images showed a remarkable decrease (46%) in the total pool of mitochondria (YFP labeled mitochondria) and even highest decrease (92%) in the active pool of mitochondria (Mitotracker red labeled mitochondria). Moreover, size distribution changed with senescence since roots of darkened plants presented increased proportion of larger mitochondria with decreased in the proportion of small ones compare with control plants. Western blot analysis showed lower mitochondrial protein in darkened plants compared with control plants. These results suggest a declining of activity and structural changes in root chondriome during senescence.