Effect of 5-Aminolevulinic Acid and Drought Stress on Antioxidant Activity and Some Physiological Parameter of Pepper (Capsicum annuum)

The present study was conducted to assess the effects of 5-aminolevulinic acid (ALA) and drought stress on some physiological parameters and antioxidant activity of pepper (Capsicum annuum L.) seedlings. Three levels of drought stress including stress-free conditions (irrigation within the field capisity)، mild stress (60% of field capacity) and sever stress (30% of field capacity) and four concentrations of ALA including 0 (as a control)، 0. 25، 0. 5 and 1 mM were investigated. In drought stress condition، growth parameters reduced، but chlorophyll a، b، total chlorophyll،carotenoids، anthocyanins and peroxidase activities increased. Application of ALA caused significant increasing of peroxidase enzyme activities، total chlorophyll content، chlorophyll a and b، carotenoids، anthocyanins and weight، length and diameter of fruits. Interaction effects of ALA and drought stress were significant in measured parameters except fruits length. The results showed that ALA could be effective approach in reducing negative effects of drought stress and maintaining antioxidant capacity of pepper.