IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CADMIUM TOXICITY IN TRANSGENIC TOBACCO CATALASE-DEFICIENT PLANTS
Autor/es:
IANNONE MF; BOCCARDO NA; DE GYLDENFELDT E; GROPPA MD; BENAVIDES MP
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión Anual de la Sociedad Argentina de investigación Bioquimica y Biología Molecular; 2012
Resumen:
Cadmium is a toxic pollutant that produces oxidative stress in several plants species. The aim of this work was to evaluate Cd toxicity in transgenic tobacco catalase-deficient (CAT1AS) and wild type plants (SR1). Plants of 45 d were treated for 8, 13, 25 days with 100 µM or 500 µM CdCl2. At day 25, CAT1AS plants accumulated more Cd than SR1 and showed smaller growth. At 25 d, iron and nitrates content decreased only in SR1 plants treated with 500 μM Cd. Chlorophyll content was reduced in both lines but more markedly in SR1. This was correlated with an increased expression of cp1, a senescence-associated gene. Ascorbate peroxidase (APOX), catalase (CAT) and guaiacol peroxidase (GPOX) activities significantly increased with 500 μM Cd in both lines, except for CAT activity, that was undetectable in CAT1AS. At 25 d, CAT1AS plants counterbalanced their CAT deficiency by increasing the basal GPOX and APOX activities. In SR1 plants, 100 µM Cd augmented cell death, electrolyte leakage, and decreased polyamines (PAS) content at 25 d. SR1 plants treated with 500 μM Cd recovered cell viability and this could be due to the increase of the antioxidant enzymes activities, GSH and PAS content. Only CAT1AS plants increased proline content at all evaluated times. These results show that CAT1AS plants are able to activate different alternative defence mechanisms against Cd toxicity compared to SR1.