NaCl胁迫对高粱成熟叶质外体和共质体中Na^+、Ca^(2+)浓度的影响

EFFECT OF NaCl STRESS ON Na~＋, Ca^(2＋) CONCENTRATIONS IN APOPLAST AND SYMPLAST OF THE EXPANDED LEAVES OF SORGHUM BICOLOR

在c（NaCl）＝200mmol／L，t＝14d胁迫条件下，盐敏感品种糖高粱（T）成熟叶生长抑制、含水量的下降和质膜透性均明显大于耐盐品种独角虎（D）；盐胁迫下，质外体和共质体中Na＋浓度明显增加，增加的幅度是质外体大于共质体，T大于D．相反，盐胁迫下质外体和共质体Ca2＋浓度均明显下降，研究结果表明：质外体Na＋浓度剧增并没有改变细胞膨压，而可能通过取代质膜上Ca2＋而破坏质膜选择透性。

The growth inhibition, decrease of water content and plasma membrane permeability of the expanded leavesof salt-sensitive Sorghum (Tanggaoliang, T)were significantly peater than those of salt-tolerant Sorghum(Dujiaohu, D)under the stress of 200 nmol/L NaCl for 14 d. Na+ concentrations in apoplast and symplast were allincreased significantly by NaCl stress, and the increased amount in apoplast was more than that in symplast, andthat of T more than that of D. ContrasUy, Ca2+ concentrations in apoplast and symplast were significantlydecreased by NaCl stress. The results showed that the significant increase of Na+ concentration in apoplast did notalter cell turgor pressure and Ca2+ on the plasmalemma possibly replaced by the increased Na+ in apoplastdamaged the selective permeability of plasmalemma, which induced salt injury.