PEG imposed water deficit and physiological alterations in hydroponic cabbage .

Abstract

Drought is one of the major environmental problems in agricultural field worldwide. The present study investigated the effects of water deficit caused by exogenous application of polyethylene glycol (PEG) on cabbage (Brassica oleracea var. capitata) grown in hydroponic culture. Root length, shoot length, dry weight, and relative water content of the seedlings significantly decreased in dose dependent manner. Significant reduction in chlorophyll, sugar and protein content, and nitrate reductase activity were recorded. The increase in proline content was recorded as the concentration of PEG increased. Increasing concentration of PEG affected the antioxidant enzymes viz. superoxide dismutase, catalase, and peroxidase activity of the seedlings through the production of reactive oxygen species (ROS) in stress condition. PEG at higher concentrations significantly enhanced the activities of antioxidant enzymes. The cabbage seedlings induced antioxidative defense system to mitigate the adverse effect resulting from altered environmental condition