【摘要】 为了研究不同K~+吸收途径在小麦耐盐机理中的作用,以小麦耐盐品种沧6005(C6005)和敏感品种矮抗58(AK58)为材料,通过K~+吸收相关抑制剂和NaCl对幼苗进行根系处理,测定并分析了根系K~+、Na~+含量、比值和质膜K~+转运相关蛋白活性的变化。结果表明:与正常条件生长小麦相比,250 mmol/L NaCl处理7 d后,2种耐盐性不同的小麦根系中的K~+/Na~+比明显降低,同时与敏感品种相比,耐盐品种能保持较高的K~+/Na~+比;NaCl胁迫下,通过3种抑制剂处理对K~+含量及K~+/Na~+比值的影响发现,与钾离子通道和非选择性阳离子通道途径相比,小麦根系K~+吸收主要通过钾载体途径;当该途径被抑制时,沧6005的K~+/Na~+比下降幅度明显高于矮抗58,表明耐盐品种更依赖该途径;NaCl胁迫下,钾载体途径被抑制时,小麦根系质膜质子泵H~+-ATPase和H~+-PPase活性明显降低,且沧6005降低幅度相对更大;NaCl胁迫下,钾载体抑制剂处理,对沧6005质膜K~+/H~+转运蛋白的抑制作用明显强于矮抗58,进一步证明上述结果。研究表明,盐胁迫下小麦主要通过钾载体途径吸收K~+,耐盐品种沧6005对钾转运载体的依赖程度更高;高NaCl环境中,细胞质膜质子泵活性和钾载体活性的提高对于维持K~+/Na~+比具有重要作用。为深入解析小麦耐盐机理提供了理论依据。更多还原

【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.更多还原