Understanding physiological and molecular adaptations of three diverse halophytic grasses under saline and sodic stresses

Abstract

Physiological and biochemical analyses of three halophytes were conducted to explore their tolerance and phytoremediation potential. The halophytes and Urochondra setulos , Sporobolus marginatus Leptochloa a fusca were categorised based on gas exchange attributes, antioxidant system, biomass production under soil salinity (E e 30-50 dS/m) and sodicity (pH 9.5-10). and produced slightly higher C L. fusca S. arginatus mbiomass under the sodic condition of pH 9.5, while in , it increased under salinity stress. Under sodic U. etulosa s conditions, showed less reduction in potassium content and maintained a higher K /Na ratio in their L. fusca + +leaf tissues. A maximum decrease in net photosynthesis was observed in (28.55%) at ECe ~ 50 dS mL. fusca -1 while minimum in (13.73%) at pH ~ 10.0. Comparatively, showed higher stomatal S. marginatus U. setulosa conductance and transpiration rate than and . At the highest pH and salinity, the L. fusca S. marginatus antioxidant activities of enzymes APX, SOD, GR and POX increased in all three halophytes. Quantitative expression of , and genes in all three halophytes increased with salt stresses. Based MnSOD NHX1 FuSOS1 on these indicators, these halophytes were categorised as salt-tolerant or alkaline-stress-tolerant.