Effects of Brassinosteroids on Postharvest Physiology of Horticultural Crops: A Concise Review

Abstract

Brassinosteroids are natural polyhydroxylated steroidal plant growth regulators or phyto-hormones. These are ubiquitous in plant kingdom and influence a wide variety of molecular, physiological and biochemical responses of plants. Brassinosteroids have also been applied and their possible role has been investigated on postharvest physiology of various horticultural crops. Brassinosteroids regulate ripening of different non-climacteric and climacteric fruits and influence colour metabolism. They inhibit activities of peroxidase and polyphenol oxidase enzymes and delay enzymatic browning. Exogenous application of brassinosteroids inhibits cell wall degradation and delays softening of fruits. In addition, their application regulates sugar and energy metabolism in different fruit and vegetable crops. They suppress lipoxygenase and phospholipase D enzyme activities and conserve higher unsaturated fatty acid contents, suppress electrolyte leakage, inhibit lipid peroxidation and maintain higher membrane integrity eventually leading to suppressed chilling injury during postharvest storage. These alleviate oxidative stress and prolong storage life potential of various horticultural crops. So, the present review summarizes various roles and mechanism of action of brassinosteroids in extending postharvest life and maintaining quality of different horticultural crops.