Abstract:

Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K+ (12 μmol/L and 6 mmol/L) to study the K+ nutrition effect on plant growth and leaf tonoplast V H+ ATPase and V H+ PPase activity. Increase of K+ supply in the culture solution markedly increased the fresh weight, dry weight and K+ content of S. salsaplants. Western blot analysis showed that the leaf V H+ ATPase of S. salsa was at least composed of A,B,C,D,E and c subunits, and their expression decreased with the increase of NaCl concentration under K+ starvation （12 μmol/L K+）, but increased under normal K+ application (6 mmol/L K+）. Leaf V H+ PPase molecular weight was about 72.6 kD and its expression increased as NaCl concentration increased under both high or low levels of K+ concentration in nutrient solution. There was a positive correlation between of V H+ ATPase or V H+ PPase activity and the amounts of their expression. Results in this study suggest that K+ nutrition plays an important role in the salt tolerance of S. salsa, and K+ is involved in the regulation of V H+ ATPase or V H+ PPase activity under salt stress.

K+营养对NaCl胁迫下盐地碱蓬生长及叶片液泡膜V-H+-ATPase和V-H+-PPase活性的影响

李平华  陈敏  王宝山^*

(山东师范大学生命科学学院,济南,250014)

对溶液培养的盐地碱蓬(Suaeda salsa L.)幼苗进行不同浓度NaCl胁迫并改变培养液中K+浓度,以了解K+营养对NaCl胁迫下盐地碱蓬幼苗生长及叶片液泡膜V-H+-ATPase、V-H+-PPase活性的影响.提高培养液K+浓度可明显增加盐胁迫下碱蓬植株的鲜重、干重,促进盐地碱蓬叶片及根部组织K+积累.盐地碱蓬叶片液泡膜V-H+-ATPase至少由A、B、C、D、E及c亚基组成,其表达量在缺K+处理(12 μmol/L K+)下随盐胁迫浓度的增加而减小,而在正常K+(6 mmol/L)培养下则随盐胁迫浓度的增加而增加;盐地碱蓬叶片液泡膜V-H+-PPase分子量为72 kD,在缺K+和正常K+供应情况下,V-H+-PPase均有较高表达.V-H+-ATPase及V-H+-PPase活性变化与其亚基表达量变化基本成正相关.结果表明: K+对盐生植物碱蓬的耐盐性有重要作用,盐胁迫下,K+可能参与了V-H+-ATPase和V-H+-PPase活性调控.

关键词 盐地碱蓬 生长 V-H+-ATPase V-H+-PPase K+营养

*通讯作者 Email: bswang@sdnu.edu.cn

Key words: Suaeda salsa, growth, VH+ ATPase, VH+ PPase, K+nutrition