Physiological Responses of Xanthium sibiricum to Salt and Alkali Stresses
An experiment was conducted to study the effects of salt and alkali stresses on the growth, photosynthesis, the concentrations and contributions of inorganic ions and organic solutes of Xanthium sibiricum seedlings treated with different contents of NaCl or NaHCO3 focusing on its physiological adaptive mechanisms against alkali stresses.The salt and alkali stresses clearly inhibited growth and photosynthesis.With increasing salinity, the Na+ content and Na+/K+ ratio in leaves were increased, with greater degrees of increase under alkali than under salt stress.Under salt stress, Na+, K+ and free proline were the main osmolytes in both roots and leaves, with the sums of the average contributions of 73.89% and 61.96% in roots and leaves, respectively.Under alkali stress, roots and leaves revealed different mechanisms of osmotic regulation.Na+ and free proline were the main osmolytes in roots under alkali stress with the average contributions of 58.44% and 16.25% respectively, and the osmotic role of K+ was small;however, in leaves, Na+, K+ and free proline all played important osmotic roles.The injurious effect of alkali stress on plants were more severe, and Xanthium sibiricum had a certain adaptability to alkali stress with the active participations of Na+, K+ and free proline in the osmotic adjustments in roots and leaves.
Xanthium sibiricumSalt and alkali stressPhysiological responseOsmotic adjustment
NETL
NSTL
万方数据
维普
