Effects of potassium chloride and nitric oxide on growth and physiological characteristics of winter wheat under salt stress

A hydroponic culture was conducted to evaluate the effects of KCl and sodium nitroprusside (SNP; a nitric oxide donor) in wheat seedlings under salt stress. Exposure to 100 mM NaCl for 7 d decreased biomass of wheat seedlings, root activity and H+-ATPase activity, significantly increased free proline content, reactive oxygen species (ROS) accumulation and lipid peroxidation, and suppressed the activity of superoxide dismutase (SOD). Moreover, NaCl stress significantly decreased the K+ and increased the Na+ content. Addition of KCl or SNP led to the increase in root activity and soluble protein content, stimulated the activity of SOD, and decreased free proline content, superoxide anion radical generation rate, and lipid peroxidation. The increased K- and decreased Na- content in the leaves of treated seedlings indicated that suitable KCl and NO addition stimulated the selective transport of K+ and Na+ to the maintain K/Na+ homeostasis.