2-Hydroxymelatonin induced nutritional orchestration in under cadmium toxicity: modulation of non-enzymatic antioxidants and gene expression.

2-Hydroxymelatonin (2-OHMT) is an important metabolite produced through melatonin interaction with oxygenated compounds. 2-OHMT pretreated seeds (50 µM, 100 µM, and 150 µM) were grown in soil contaminated with 50 mg kg cadmium. Cadmium imposed stress reduced seed germination, growth, biomass production, and chlorophyll (Chl) content in seedlings. 2-OHMT application emphatically revamped germination, shoot length, root length, and plant biomass production. The 2-OHMT pretreatment modulated expression levels of plasma membrane H-ATPase genes of including and . This biomolecule amplified the accumulation of antioxidants such as glutathione, proline, phenolics, and flavonoids. The reduced Cd-uptake in 2-OHMT treated seedlings encouraged uptake of essential plant nutrients. Furthermore, conjugated increase of indole acetic acid contents and ethylene production rate were observed in 2-OHMT treated seedlings in a dose-dependent manner. The improved nutritional content in 2-OHMT applied seedlings was ascribed to enhanced expression of H-ATPase regulating genes besides increased amount of non-enzymatic antioxidants in Cd-stressed plants. The present novel study elucidates the potential of 2-OHMT in improving nutritional content in cucumber plants by modulation of non-enzymatic antioxidants and gene expression.