Transformation of photosystemⅡ function during greening in golden leaves of Ligustrum vicaryi

Golden sun leaves of Ligustrum vicaryi could turn green after shadowing treatment. In this paper, the transformation of photosystemⅡ (PSⅡ) in the regreening course was studied by means of two kinds of chl a fluorometer: PAM2100 and PEA. The results indicated that Fv/Fm, F0 and OJIP transients of the golden sun leaves were lower than that of the green shade leaves. Relative intensity of J phase of golden leaves under the double normalization of OP was higher than that of green leaves. Furthermore, the golden leaves turned green when they were overshadowed, and there were two steps in the recovery course of PSⅡ. Firstly, in the first 2 weeks, F0 increased while Fv/Fm declined; secondly, after 2 weeks, F0 declined while Fv/Fm increased. After two months shadowing, F0, Fv/Fm and OJIP of the golden leaves were similar to that of the shade green leaves. It suggested that most of PSⅡ units of L. vicaryi leaves would be damaged in sunshine condition, and activity of the accepter side was lower than that of donor side in the remainder activated PSⅡ of golden leaves. During shadowing process, the recovery rate of reaction center and the lightharvesting antenna system of PSⅡ of the golden leaves were not synchronous, but both of them could recover to the normal state as that of green shade leaves after 2 month shadowing.