What question did this study set out to answer?

This research aims to explore the effects of omeprazole on hormonal responses and growth of tomato plants under nitrogen and water deficits.

May 7, 2026Open Access

Hormonal Modulation by Omeprazole Improves Tomato Growth under Single and Combined Water and Nitrogen Deficits

Key Points

This research aims to explore the effects of omeprazole on hormonal responses and growth of tomato plants under nitrogen and water deficits.
Tomato plants were treated with omeprazole (0 and 1μM) under single and combined nitrogen (50%N) and water (50%W) deficits.
Hormonal analysis was conducted to assess shifts in abscisic acid, indole-acetic acid, salicylic acid, and jasmonic acid levels.
Plant performance was evaluated based on total dry weight, efficiency of nitrogen and water usage, and photosynthetic rates.
OMP increased total dry weight by 23% under deficit conditions, enhancing nitrogen use efficiency and water use efficiency by 23% and 17%, respectively.
Combined deficits led to distinct hormonal shifts, with OMP-treated plants showing 35% lower root ABA but improved root IAA by up to 27%.
OMP improved photosynthetic rates and reduced lipid peroxidation in shoots, indicating protective effects against stress.

Abstract

Omeprazole (OMP) has emerged as a promising protective compound against abiotic stress and a potential plant growth promoter, yet its role under combined stress and underlying mechanisms remains unclear. This study assessed the hormonal response of tomato plants to single and combined nitrogen (N) and water (W) deficits (50%N and/or 50%W) and the impact of OMP application to the root zone (0 and 1μM) under these conditions. Combined deficit induced distinct hormonal shifts, including decreased shoots’ abscisic acid (ABA) and indole-acetic acid (IAA), alongside increased salicylic acid (SA), jasmonic acid (JA) and jasmonic acid-isoleucine (JA-Ile). OMP consistently improved plant performance irrespective of the growth conditions, increasing total dry weight by 23% and enhancing nitrogen use efficiency and water use efficiency by 23% and 17%, respectively. Root growth stimulation in OMP-treated plants correlated with higher root IAA under control (+9%), N deficit (+27%), and W deficit (+20%) conditions, while combined deficit plants exhibited 35% lower root ABA without significant root biomass gain. OMP also improved photosynthetic rates and decreased shoots’ lipid peroxidation, suggesting a protective effect. Hormonal modulation by OMP included lowering stress-related hormones - restoring JA and JA-Ile to control levels and reducing phaseic acid and SA under W deficit - while promoting IAA, a growth-related hormone. Collectively, these findings indicate that the combined deficit triggers a distinct hormonal profile from single deficits, and that OMP acts as both a stress alleviator and a growth promoter under N and W limitations by modulating hormonal, physiological and biochemical responses in a condition-specific manner. • Combined N and W deficit triggers a distinct hormonal profile from single deficits • OMP enhances photosynthesis and reduces oxidative damage under N and W deficit • OMP modulates plant hormonal response in a deficit-specific manner • OMP reduces endogenous levels of several stress–related hormones • It markedly decreases JA and JA-lle under single and combined N and W deficits

Hormonal Modulation by Omeprazole Improves Tomato Growth under Single and Combined Water and Nitrogen Deficits

Key Points

Abstract

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