Role of melatonin in improving growth, yield quantity and quality of Moringa oleifera L. plant under drought stress

Abstract

Subjecting M. oleifera plant to drought stress caused significant decreases in growth, photosynthetic pigment, indole acetic acid (IAA), element contents, yield, and yield attributes, meanwhile increased lipid peroxidation is expressed as malondialdehyde (MDA) and various antioxidant enzymes as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). On the other hand, foliar treatment with different concentrations of melatonin significantly increased growth parameters, yield quantity, and quality of M. oleifera plant at normal and drought-stressed conditions via improving photosynthetic pigments (IAA), phenolic and element contents, and antioxidant enzyme systems, whereas declined malondialdhyde (MDA) contents as compared with their corresponding untreated controls (M0). Foliar treatment with 100 mM melatonin showed the greatest growth criteria and yield components of M. oleifera plants at either normal irrigation or under drought stress. This concentration also improved amino acid constituents of the yielded M. oleifera plants compared with other concentrations under normal and stress conditions.