Exogenous maize grain embryonic extract enriched with some biostimulants confers drought stress tolerance by promoting tomato's growth, photosynthetic efficiency, antioxidant defense, and yield and quality.

Abstract

One of the primary stresses affecting tomato plant growth and yield is water limitation (WL). Using a completely randomized design with three replications, the effects of WL alone or with exogenous foliar application of maize grain embryos extract enriched with bio-stimulant (e.g., gibberellic acid, ascorbate, and selenium) (MEEst) on tomato plant growth and some related parameters. WL decreased leaf pigment levels, photosynthetic efficiency, water use efficiency (WUE), nutrient content, relative water content, and membrane stability index; however, increased electrolyte leakage. These negative effects resulted in a clear decrease in the growth parameters and yield. However, by applying MEEst as foliar spraying at two concentrations (i.e.,7.5 and 15.0%) to the tested plants growing under two irrigation regimes (100 and 60% of soil water holding capacity), the detrimental effects of WL stress were lessened. It also improved photosynthesis and leaf pigmentation, decreased electrolyte leakage, and raised membrane stability index, nutrient content, relative water content, and WUE. Positive effects are observed in the growth parameters, yield, and fruit quality. Thus, MEEst is a useful, long-lasting, and eco-friendly approach for reprogramming plant responses and mitigating the deleterious consequences of WL stress.