Interciencia
versión impresa ISSN 0378-1844
Resumen
RAMIREZ-SERRANO, Rogelio et al. Antioxidant enzymatic response of hot pepper (capsicum annuum l.) Under saline stress conditions. INCI [online]. 2008, vol.33, n.5, pp.377-383. ISSN 0378-1844.
A pot experiment was carried out with hot pepper (Capsicum spp. cv. "Caballero") to investigate the response of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in fruits of this species under moderate saline conditions. The hot pepper plants were exposed during 90 days to five treatments: I) control (potable water: 1.3dS·m-1), II) NaCl (2.8dS·m-1), III) NaCl (4.0dS·m-1), IV) sea water (2.8dS·m-1), and V) sea water (4.0dS·m-1). The hot pepper fruits were collected in the ripening phase and the ripening pigmentation, number of fruits, length, width, fresh weight, mineral contents (Ca2+, Mg2+, K+, Mn2+, Na+ and Cl-), proteins, superoxide dismutase (SOD) and catalase (CAT) activity, lipoperoxidation and ascorbic acid were measured. The results showed that morphological variables number, length, width and fresh weight of fruits remained without statistical significant differences between treatments but stayed the same as, or slightly less than that of the control. Saline treatments caused differences in fruit ripening pigmentation, changing to red color at 4.0dS·m-1 when NaCl or sea water were applied. Content of soluble proteins increased from the control to 2.0dS·m-1 but decreased as electrical conductivity (EC) increased with NaCl or sea water. Calcium, magnesium, potassium and manganese content, decreased as CE increased, but sodium and chloride showed the contrary, being higher at 4.0dS·m-1 with NaCl. Ascorbic acid remained unchanged between treatments, although slightly increased at 2.8dS·m-1 (NaCl). Salt stress was found to increase lipoperoxidation, superoxide dismutase and catalase activities being higher at 4.0dS·m-1 when NaCl was used, but this enzymatic response in fruits at 2.8dS·m-1 in both saline sources, seemed to have maintained the cellular homeostasis, without altering its ripening. These findings suggest the possibility to use the enzymes SOD and CAT as ripening biomarkers in hot pepper fruits under saline stress, because they showed a high activity in the ripening of fruits when NaCl or sea water was used.
Palabras clave : Biomarcadores; Catalasa; Salinidad; Superóxido Dismutasa.