Adequate potassium application enhances salt tolerance of moderate-halophyte Sophora alopecuroides

Abstract

A sand-culture experiment was carried out to investigate the effects of exogenous K2CO3 on salt resistance of moderate-halophyte Sophora alopecuroides. Thirty-day-old seedlings of S. alopecuroides were treated by two levels of salinity (0 and 200 mmol/L NaCl) in combination with four levels of K2CO3 (0, 5, 10 and 15 mmol/L). Gas exchange, chlorophyll content, K+/Na+ ratio, relative electrical conductivity (REC) and antioxidant enzymes activities were monitored after 15-day treatments. The results showed that adequate K+ application effectively counteracted the adverse effects of salinity, in which gas exchange, K+/Na+ ratio and chlorophyll content significantly increased, while REC and antioxidant enzymes activities considerably decreased. The results suggest that adequate potassium application may effectively enhance plant photosynthetic capacity and reduce the oxidative stress in the salinity-stressed S. alopecuroides.

Keywords

• leaf senescence
• ascorbate-glutathione cycle
• superoxide dismutase
• defense against lipid peroxidation