Different Doses of the Enhanced UV-B Radiation Effects on Wheat Somatic Cell Division

Being sessile, plants are continuously exposed to DNA-damaging agents presenting in the environment such as ultraviolet (UV). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315 - 400 nm; UV-B, 280 - 315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damages. This paper mainly used different doses of the enhanced UV-B radiation (B₁ group: 4.05 kJ•m^-2•d^-1, B₂ group: 10.08 kJ•m^-2•d^-1, B₃ group: 7.05 kJ•m^-2•d^-1, B₄ group: 23.02 kJ•m^-2•d^-1) treatment wheat, then, explored on the growth of wheat root and wheat root tip cell of chromosome aberration effect. In wheat, root-tip cells were observed with confocal laser scanning microscopy (CLSM), the results showed that low doses of B₁ group (4.05 kJ•m^-2•d^-1) promoted the growth of wheat root and cell mitosis frequency. But high dose of B₂ group (10.08 kJ•m^-2•d^-1), B₃ group (17.05 kJ•m^-2•d^-1), B₄ group (23.02 kJ•m^-2•d^-1) inhibited the growth of wheat root tip, and made crooked growth of wheat root, and inhibited the wheat root tip cell mitotic frequency and processed that induce root tip cells of wheat produce all kinds of aberration of chromosome in the interphase containing “multiple nucleoli nuclei”, “incomplete nuclei”, “long round nuclei”, “bean sprouts nucleus”. In mitosis M period contains “dissociative chromosome”, “chromosome bridge”, “adhesion chromosome”, “multi-bundle divide”, “nuclear anomalies”. After, high doses of enhanced UV-B radiation treatment, most of the cell cycle anomaly concentrated in mitosis interphase. In mitosis M period, with UV-B radiation dose enhanced chromosome aberration rate was on the rise and the aberration types also increasing.