Acetate-induced modulation of ascorbate: glutathione cycle and restriction of sodium accumulation in shoot confer salt tolerance in Lens culinaris Medik.

摘要

Physiological and biochemical changes in six-day-old hydroponically grown lentil seedlings exposed to 100 mM salinity stress with or without 5 and 10 mM Na-acetate were studied. Results showed that salt stress reduced recovery percentage, fresh weight(FW), chlorophyll (chl) content, disturbed water balance, disrupted antioxidant defense pathway by decreasing reduced ascorbate content, and caused ion toxicity resulting from increased Na+ accumulation, severe K+ loss from roots in hydroponic culture.However, exogenous application of Na-acetate improved the seedling growth by maintaining water balance and increasing chl content. Furthermore, Na-acetate application reduced oxidative damage by modulating antioxidant defense pathway, and sustained ion homeostasis by reducing Na+ uptake and K+ loss. In the second experiment in glass house, we investigated the role of Na-acetate on lentil for long-term salinity. Acetate application increased FW and dry weight, reduced oxidative and membrane damage, and lowered the accumulation of Na+ in shoot compared with salt stressed seedlings alone. From the results of both experiments, it is clear that the exogenous application of Na-acetate enhanced salt tolerance in lentil seedlings.