Sucrose metabolism during maturation and ripening of mango cultivars.
Kumar S., Das D. K., Mishra M., Singh A. K., Prasad U. S.
Author Affiliation: Biosciences Research Centre, Department of Botany, TNB College, Bhagalpur University, Bhagalpur 812?007, India.
Plant Physiology & Biochemistry (New Delhi) 21 : 27-32
Abstract : High activities of both sucrose synthetase [sucrose synthase] and invertase [?-fructofuranosidase], indicative of active sucrose metabolism during fruit maturation and ripening, are more characteristic of mango cv. Fazli than cv. Zardalu. Sucrose concentrations and the activities of these enzymes were studied in fruits of both cultivars harvested at various stages of maturity and stored at 38°C and 70% RH. Cycloheximide and kinetin treatments were applied to Zardalu fruits to study their effects on ripening. In both cultivars, sucrose was far more abundant than glucose and fructose at the 2/3-mature and over-ripe stages. Postharvest application (1-min dip) of 1 or 100 µg kinetin/ml or 100 µg cycloheximide/ml to fully mature Zardalu fruits 80 days after anthesis increased sucrose synthetase activity compared with controls dipped in distilled water; this activity was unaffected by 1 µg cycloheximide/ml. At the 1/3- and 2/3-ripe stages, invertase activity was only slightly affected by kinetin and cycloheximide, but at later stages, it was reduced in fruits treated with 1 or 100 µg cycloheximide/ml, slightly reduced in fruits treated with 1 µg kinetin/ml and eventually increased in those treated with 100 µg kinetin/ml.