The effect of Cd on ultrastructure of wheat

Transmission Electron Microscope (TEM) was used to investigate the damage of wheat seedlings by cadmium and the distribution of Cd2+ in different parts of wheat seedlings was discussed. Experiments show that Cd is more mobile than other metals and the pollution damages the root tip cells. In addition, lots of abnormal symptoms were observed, including cell-wall thinning and cell deforming, cytoplasm and organelle swelling or even becoming vacuolization, nuclear membrane becoming disrupted and square cells being formed. The damage of Cd2+ on wheat leaves was less serious than that of root tips. Cd pollution may promote cell cleavage, resulting in swelling and disturbance of the layered structure of chloroplast, leading mitochondrion to swelling or even becoming round. The dense electron particles exist in ektexine, extracellular matrix, vacuolar of root cells as polluted by low concentration of Cd and exist outer the wall and inside the cytoplasm of leaves cells as polluted by different levels of Cd.