Physiological and biochemical insights for salt stress tolerance in the habitat-indifferent halophyte Salsola drummondii during the vegetative stage

We investigated changes in the growth parameters, sodium accumulation, element composition, and antioxidant enzyme activity of habitat-indifferent Salsola drummondii Ulbr. during the vegetative stage. Our results show that S. drummondii grows very well in salt concentrations up to 500 mmol/L NaCl. There were no significant differences in the water content and biomass of shoots, roots, and leaves between the control and plants treated with 500 mmol/L NaCl (equivalent to the salinity of seawater). However, chlorophyll and carotenoid content was reduced at higher salinities, which was associated with a significant increase in H2O2 and malondialdehyde. Our results revealed that S. drummondii can translocate Na+ from the roots to the shoots, with Na+ content in the shoots being higher than that in the roots. In contrast, the S. drummondii plants treated with NaCl exhibited a significant decrease in the levels of essential ions in different plant organs. Proline concentration significantly increased with increasing salinity, and significant changes were observed in guaiacol peroxidase, catalase, and ascorbate peroxidase levels under different salinity treatments. The activity of antioxidant enzymes and proline accumulation in S. drummondii plants correlated with enhanced salt tolerance. Our findings provide novel insights into the salt tolerance of S. drummondii.