MITIGATION OF THE OXIDATIVE EFFECTS OF SALT STRESS ON GROWTH AND PHOTOSYNTHESIS BY THE EXOGENOUS TREATMENT OF TREHALOSE IN TRIGONELLA FOENUMGRACUM

Trehalose (Tre) is an important sugar and acting as osmolyte in stress mitigation.Experiments were performed to analyze the positive impact of Tre (1, 5, 10, and 20 mM) supplementation on growth, antioxidant system, osmolytes, secondary metabolites, and photosynthetic parameters of Trigonella foenum-graecum under salt stress.Treatment of 100 mM NaCl declined growth parameters, chlorophyll, and the photosynthetic gas exchange parameters however, Tre supplementation alleviated the decline in the attributes considerably at all levels and evident effects were observed at 10 mM Tre. Treatment of Tre resulted in reduced hydrogen peroxide, electrolyte leakage, and lipid peroxidation in both controls (non-stressed) and NaCl-treated plants.The accumulation of glycine betaine, sugars, proline, and trehalose increased by the supplementation of Tre at all levels and caused further increase when added to NaCl-stressed plants.The decline in relative water content was alleviated by the Tre supplementation.In addition, the application of Tre imparted an apparent augmentation of antioxidant activities.Furthermore, the concentrations of ascorbic acid and reduced glutathione increased by the Tre application under normal and NaCl stressed plants enabling the antioxidant system to eliminate the free radicals more effectively.Salinity increased the total phenols and flavonoids, and Tre application imparted further enhancement in their accumulation.The accumulation of sodium in Tre-supplied plants was reduced compared to NaClstressed plants.The effects of Tre were concentration dependent and the most beneficial was 10 mM.