BECAS
MENDEZ andrea Analia Elena
congresos y reuniones científicas
Título:
Redox imbalance as growth inhibitor during metal stress in plants
Autor/es:
AAE MENDEZ; LB PENA; RA BARCIA; SM GALLEGO
Lugar:
Olomouc
Reunión:
Congreso; 12th PhD Student Conference of Plant Experimental Biology; 2014
Resumen:
Abiotic stress is greately associated with plant
growth inhibition and redox cell imbalance. In the present work, we have
investigated in which way oxidative posttranslational modifications (PTM) of
proteins related to cell cycle may be implicated in post-germinative root
growth reduction caused by cadmium, by methyl viologen (MV) and by hydrogen
peroxide (H2O2) in wheat seedlings. Although cadmium is considered a redox
inactive metal, reactive oxygen species were detected in the apex root of
metal-treated seedlings. Oxidative stress hastened cells displacement from the
cell division zone to elongation /differentiation zone, resulting in a
shortened meristem. The number of cells in the proliferation zone was lower
after MV, H2O2 and 10uM Cd2+ treatments compared to control. All treatments
increased protein carbonylation. Although no modification in total
Ub-conjugated proteins was detected, oxidative treatments reduced cyclinD and
CDKA protein ubiquitination, concomitantly with a decrease in expression of
cyclinD/CDKA/Rb/E2F-regulated genes. We postulate that ROS and oxidative PTM
could be a part of a general mechanism, specifically affecting G1/S transition
and progression through S phase. This would rapidly block cell cycle
progression and would allow the cellular defense system to be activated.