Abstract
The effects of elevated UVB on the relationship between accumulation of anthocyanins and UV-absorbing compounds and levels of cyclobutane pyrimidine dimer (CPD) with leaf age in near-isogenic line (NIL) for purple leaf gene, pl of rice with a genetic background of Taichung 65 (T-65) rice, were examined. The following things were clear. First, the growth and Rubisco content in the leaf of the NIL were significantly retarded by supplementary UVB, despite it contained higher amounts of these pigments. Second, these pigments functioned effectively for reducing susceptibility to CPD induction by a challenge UVB exposure, but not by chronic UVB exposure. Third, anthocyanins functioned effectively lowering of CPD photorepair by challenge UVB exposure to blue/UV-A radiation. In conclusion, accumulation of anthocyanins and UV-absorbing compounds did not effectively function as screening against damages caused by elevated UVB in NIL.
