镉胁迫下小麦根尖分生细胞中Ca^(2+)分布的变化

Changes of Ca ^(2+) Distribution in Root Apical Meristematic Cells of Wheat under Cadmium Stress

运用透射电镜细胞化学方法对镉胁迫下小麦根尖分生细胞中 Ca2 + 分布的变化进行了观察。在正常生长条件下 ,Ca2 + 广泛分布于细胞质、细胞核、细胞间隙中 ,特别是液泡中有大量的 Ca2 + ;在镉胁迫条件下 ,细胞质基质内Ca2 +减少 ,而细胞核、质膜与细胞壁之间、细胞壁中 Ca2 +明显增多 ,细胞液泡化 ,液泡中仍有较多 Ca2 +。结果表明 ,Cd2 + 引起细胞中原有 Ca2 + 分布发生明显变化 ,这很可能引起细胞生理功能紊乱 ,进而影响植物的生长。

Changes of Ca 2+ distribution in root apical meristematic cells of wheat under cadmium stress were observed with electron microscopic-cytochemical method.When the roots grew in non-cadmium environment,it was shown that the calcium antimonates distributed in cytoplasm,nucleus and intercellular spaces,especially in the vacuoles of cytoplasm.When the roots grew in cadmium stressed environment,the amount of calcium antimonates in cytoplasm decreased,while the amount of calcium antimonates in the nucleus,between plasma membrane and cell wall,and in cell wall increased.Moreover,the cells vacuolizated,and there were some calcium antimonates in vacuoles.These results indicated that cadmium could disturb cellular metabolism by disrupting Ca 2+ homeostasis and affect the growth of roots.