Cadmium induces different biochemical responses in wild type and catalase-deficient tobacco plants

IANNONE MF; GROPPA MD; BENAVIDES MP

ENVIRONMENTAL AND EXPERIMENTAL BOTANY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 109 p. 201 - 211

0098-8472

The response of tobacco (Nicotiana tabacum L.) wild type SR1 and catalase-deficient CAT1AS plants wasevaluated after exposure to CdCl2. CAT1AS plants accumulated more Cd than SR1 plants, and this wasassociated with reduced growth, but higher chlorophyll content and cell viability. Despite catalase defi-ciency, CAT1AS plants did not accumulate more H2O2than the wild line when exposed to Cd, probably dueto the fact that CAT1AS plants counterbalanced their catalase deficiency by increasing the constitutiveguaiacol peroxidase and ascorbate peroxidase activities and by reducing the basal NADPH oxidase-likeenzyme activity. Both lines could activate their antioxidant system upon Cd stress, although the stressresponse pathways showed wide differences in the mineral and nitrogen metabolism, since the wild-typeline had reduced nitrates and iron content, while CAT1AS maintained the same level of nitrates and Fethan that of non-treated plants, and responded with a significant increase in proline. The results showedthat, unlike previous reports using other type of stress with the same line plants, catalase did not play acrucial role in protecting against Cd toxicity and CAT1AS plants, compared to SR1, were able to activatealternative defence mechanisms against Cd toxicity.