苜蓿愈伤组织盐适应过程中的溶质积累

Solute Accumulation in the Process of Adaptation of Alfalfa Callus to NaCl

通过一步筛选获得耐1.0％NaCl的苜蓿愈伤组织(S-1)。比较盐适应(S-1)和未经适应愈伤组织(S-0)在1.0％NaCl培养基上溶质积累的情况,渗透势的下降S-0略低于S-1;S-0细胞变小,S-1细胞无明显变化,含水量S-0比S-1下降多,Na^+和Cl^-大量积累,S-0低于S-1,K^+浓度升高,但含量下降,S-0比S-1下降多,脯氨酸和可溶性还原糖含量的增加S-0远高于S-1。对于含盐培养基上S-0和S-1渗透调节模式的差异及溶质积累与盐适应的关系,可以认为增加Na^+和Cl^-积累是苜蓿愈伤组织盐适应的主要方面,脯氨酸和可溶性还原糖的增加在渗透适应上只起部分作用。

By means of one-step selection, alfalfa callus adapted to 1.0% NaCl was established. By comparing solute accumulation of NaCl-unadapted (S-0) with NaCl-adapted (S-1) callus grown on a medium containing 1.0% NaCl, it has been shown that: the osmotic potential of S-0 callus decreased more than that of S-1 callus; the diameter of S-0 cells was reduced, but that of S-1 cells was not; water content of S-0 callus decreased more than that of S-1 callus; Na^+ and Cl^- accumulated greatly less in S-0 than in S-1 callus; the levels of proline and water-soluble reducing-sugars were enhanced more in S-0 than in S-1 callus; K^+ content of S-0 callus was reduced more than that of S-1 callus. The differences in the mode of osmotic regulation between salt-adapted and salt-un adapted callus, and the relationship between solute accumulation and salt adaptation were discussed. It is proposed that Na^+ and Cl^- accumulation is the main component of salt adaptation of alfalfa callus and the increase of proline and water-soluble reducing-sugar plays only a part of role ill salt tolerance.