ABSTRACT
Objective: To investgate the effects of NaCl stress on the growth and physiological characteristics of Thermopsis laceolata callus, and to reveal the physiological mechanism of T. laceolata under salty environment at the cellular level. Methods: The callus was cultured on the subculture medium with NaCl (0.2%-1.2%), and the contents of soluble sugar, soluble proteins, proline, and malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were determined and analyzed. Results: The callus growth expressed a decreasing trend with NaCl concentration increasing (≤ 0.8%) but had no significant difference to contrast. Nevertheless, the callus grew very slowly with NaCl concentration increasing (> 0.8%); the contents of soluble sugar and free proline increased firstly and then decreased, but were higher than those of the control group; the content of soluble protein and the activities of SOD, CAT, and POD increased firstly and then decreased; MDA accumulated slowly at salinity (≤ 0.8% NaCl), then increased rapidly at salinity (> 0.8% NaCl). Conclusion: T. laceolata callus has an adaptability to salty environment (≤ 0.8% NaCl), and the callus could alleviate the salty injury by increasing the contents of the osmotic regulation substances, such as proline and soluble sugar, decreasing the osmotic potential, and increasing the activities of anti-oxidative enzyme.