MENDEZ andrea Analia Elena
congresos y reuniones científicas
Redox imbalance as growth inhibitor during metal stress in plants
AAE MENDEZ; LB PENA; RA BARCIA; SM GALLEGO
Congreso; 12th PhD Student Conference of Plant Experimental Biology; 2014
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.