Changes of Ca²⁺ Distribution in Root Apical Meristematic Cells of Wheat under Cadmium Stress

Changes of Ca²⁺ 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.