Physiological responses of maize to elemental sulphur and cadmium stress

Abstract

The physiological response to application of elemental sulphur (S) and cadmium (Cd) of maize (Zea mays L.) grown for 60 days in pot soil was studied. The S was added into the soil with 2 rates (0 and 50 mmol/kg) and Cd was added in solution in 4 rates (0, 20, 50, 100 mg/kg). All the S and Cd were added before planting. Shoot biomass decreased with the application of Cd to the soil whether S was applied or not. The application of S and Cd to soil led to an increasing accumulation of Cd in the shoots of maize. The concentration of chlorophyll was reduced significantly in Cd-treated plants with or without supplementary S. The content of malondialdehyde (MDA) was increased significantly in treatments with S and Cd, compared to the control. The activity of peroxidases (POD) was increased but catalase (CAT) was decreased in plants treated with Cd, again with or without S, in comparison with control. POD and CAT activities decreased in all the Cd treated plants with S, as compared to the plants without S. The results suggest that Cd reduces the crop growth, concentration of chlorophyll and activity of CAT, but increases the content of MDA and activity of POD. S supplies decrease the content of MDA, activities of POD and CAT, as compared to zero S supplies at the same rate of Cd application.

Oxidative stress and change in plant metabolism of maize (Zea mays L.) growing in contaminated soil with elemental sulfur and toxic effect of zinc

“…However, application of 640 mg/kg S induced a significant increase in POD activity in plants treated with 1000 mg/kg Zn. The reduction of POD activity as a result of application of S was observed in plants grown under conditions of cadmium stress (Cui and Wang 2006). Therefore, POD activity appears to be dependent on the plant species, the metal, the elemental S used for the treatment and the intensity of the stress.…”

“…The chlorophyll (a + b) concentration was determined in 96% ethanol extracts of 0.5 g fresh leaf tissue as described by Cui and Wang (2006).…”

“…Total superoxide dismutase (SOD, EC 1.15.1.1) activity was determined according to Giannopolitis and Ries (1977). Catalase (CAT, EC 1.11.1.6) activity was determined by following the consumption of H 2 O 2 (extinction coefficient 39.4 mmol/cm) at 240 nm for 3 min (Cui and Wang 2006). Peroxidase (POD, EC 1.11.1.7) activity was determined as described by Cakmak and Marschner (1992).…”

“…The lipid peroxidation was determined by measuring the level of malondialdehyde (MDA) using the method of Cui and Wang (2006).…”

Enxofre na atenuação dos efeitos tóxicos do cádmio no capim-tanzânia

“…Atividades de mineração, fundição, fabricação de fertilizantes fosfatados, descarte de baterias usadas, deposição de resíduos de esgotos municipais e processos industriais estão entre as principais atividades que resultam na contaminação do ambiente por cádmio (CHOU et al, 2011;CUI;WANG, 2006). Também existem as fontes naturais de contaminação, como emissão de gases na atividade vulcânica, queima de florestas e transporte de partículas de fuligem e solo pelo vento (FISHBEIN, 1993), além do próprio material de origem do solo (KABATA-PENDIAS, 2001).…”