Hydrogen Sulfide and 5‐Aminolevulinic Acid Synergistically Enhance Drought Tolerance in Tomato (Solanum lycopersicum L.)

OpenAlex İngilizce

ABSTRACT Enhancing crop drought tolerance is crucial for food security amid climate change. This study examines how 5‐aminolevulinic acid (ALA) and hydrogen sulfide (H 2 S) can improve drought resilience in tomato plants, which are essential for sustainable food production. Drought stress was induced using 12% PEG‐6000. Plants were pre‐treated with 25 mg L −1 ALA and 0.1 mg L −1 hypotaurine (HT), followed by 0.2 mM sodium hydrosulfide (NaHS) treatment to assess the effects on plant physiological effects over 10 days. Drought stress reduced plant dry weight, chlorophylls ( a and b ), F v / F m , leaf water potential, and relative water content, while increasing glycine betaine (GB) and proline levels. Additionally, drought stress elevated NADPH oxidase (NOX) and glycolate oxidase (GOX) activities, inducing oxidative stress and membrane damage. ALA and NaHS enhanced plant growth, photosynthesis, proline, GB, ALA content, ATP synthase, and ATPase activities, while mitigating NOX and GOX activities, thereby reducing and H 2 O 2 radicals. ALA alone boosted L‐DES activity, promoting H 2 S accumulation. However, ALA + HT reduced H 2 S levels, compromising ALA's efficacy. NaHS with ALA + HT reinstated positive effects by restoring H 2 S levels. Biochemical assays confirmed ALA and NaHS promoted H 2 S accumulation, bolstering antioxidants, mitigating lipid peroxidation, suggesting their drought resilience potential in tomatoes.