Abstract: In order to examine the effects of different K⁺ uptake pathways on the mechanism of salt-tolerance of wheat. Winter wheat cultivars salt-tolerant C6005 and salt-sensitive AK58 were used to investigate the contents of K⁺ and Na⁺and K⁺/Na⁺ ratios and plasma membrane proteins activities under NaCl stress and co-treatments with TEA (Tetraethylammonium chloride,K⁺passway inhibitor),NEM (N-Ethylmaleimide,transporter inhibitor) and Ba (NO₃)₂(NSCCs inhibitor)respectively in the study.The major results were as follows:250 mmol/L NaCl treatment for 7 days significantly (P <0.05) decreased the K⁺/Na⁺ ratios of root both salt-tolerant and sensitive cultivars compared with their controls,and C6005 could retain higher K⁺/Na⁺ ratios than AK58 under NaCl stress. Comparatively,NEM had greater inhibition on both K⁺ contents and K⁺/Na⁺ ratios than TEA and Ba(NO₃)₂ in both salt-tolerant and sensitive cultivars. Under NaCl stress,when K⁺ transporters were inhibited,K⁺/Na⁺ ratios of C6005 were decreased more obviously than that of AK58,the activities of plasma membrane H⁺-ATPase and H⁺-PPase in both cultivars were decreased,and the change extend was larger in C6005. Meanwhile,the activities of K⁺/H⁺ transporters in C6005 were inhibited more violently than that in AK58 when pretreated with NEM under stress. The results suggested that K⁺ transporters were the primary approach for K⁺ absorption under salt stress in wheat,especially in salt-tolerant cultivar,and the energy mainly came from H⁺-ATPase and H⁺-PPase of proton pump of plasma membranes under salt stress. This work will provide theoretical basis for further analyzing the mechanism of salt-tolerance of wheat.

Key words: Wheat, Salt stress, K⁺/Na⁺, Plasma membrane proteins, K⁺ absorption

CLC Number: 

• S512.01