Alleviation of drought stress and mediated antioxidative defense in wheat through moringa leaf extract hormesis

Drought is a key environmental limitation that impacts agricultural productivity globally. Allelopathic hormesis, low dose stimulatory effect of allelochemicals, offers a realistic and practicable solution to enhance plant drought tolerance. This study aimed to see how effective moringa leaf extract is at reducing the negative impacts of drought in wheat. Therefore, three-factor study was conducted viz., drought imposition by maintaining field capacity at 100%, 60%, and 30%, moringa leaf extract from 0.5%, 1.0%, 1.5%, 2.0%, 2.5% to 3.0%, including control and water priming, and wheat cultivars (Ihsan-2016, and Galaxy-2013). Water deficit, typically at 30% FC, inhibited wheat plant growth; however, 2.5% application of moringa leaf extract significantly mitigated the negative effects of drought. Compared to control at 30% FC, primed seeds with 2.5% moringa leaf extract triggered the morphological traits like seedlings length, their fresh and dry weights in the range of 2–160% in both wheat cultivars. Besides, compared to control at 30% FC, antioxidant enzymes triggered in the range of 12–114%, reduced hydrogen peroxide contents (14–30%), and improved the contents of photosynthetic pigments (27–150%) in both wheat cultivars through the application of 2.5% moringa leaf extract. Moreover, higher drought tolerance induced through dynamic growth in wheat-cultivars under moringa leaf extract application was associated with increased chlorophyll content, physiological attributes, enhanced mechanism of antioxidant defense, and reduced H2O2 based damaging effect.