盐胁迫条件下三角滨藜叶片中盐分的积累与分配

用扫描电镜和能谱仪测定不同浓度NaCl胁迫2wk后的三角滨藜幼叶和成熟叶中Na 在细胞外和细胞内的分布情况,并利用原子吸收分光光度计测定叶片中Na 的积累量,同时还观测了盐囊泡及其与盐的积累、分泌之间的关系.结果表明,在盐胁迫下,三角滨藜叶片中的Na 积累量随根外溶液盐浓度的升高而增加,而盐囊泡的含盐量并无显著变化.同时发现,叶片中的Na 主要积累在细胞内.因此,可以认为,三角滨藜主要靠吸收并在细胞内积累Na 来降低渗透势,保证植株的水分吸收,而三角滨藜的盐囊泡在盐分分泌与抗盐中并无实质性作用.图2表3参12

Accumulation and Distribution of Salt in Leaves of Atriplex triangularis under Salt Stress

The distribution of Na in intracellular and extracellular spaces in leaves of arrowleaf saltbush(Atriplex triangularis)subjected to salt stresses was investigated by using a scanning electron microscope facilitated with an Auger electron spectrometer.The role of salt bladders in salt resistance of A.triangularis was analysed in terms of salt accumulation and secretion.The initial results showed that the accumulation of Na in leaves of A.triangularis increased with the increasing of salt concentration in root-external solution,and small change in salt content took place in the salt bladders.Further analysis indicated that most of the absorbed Na was accumulated within leaf cells.It is thus suggested that A.triangularis plants absorb and accumulate Na intensively in cells for water absorption in combating the osmotic stress induced by salt,and that the role of salt bladders be negligible in salt secretion or salt resistance in A.triangularis plants.Fig 2,Tab 3,Ref 12