Abstract:

The photodamage processes of PSⅠ particles isolated from two wheat cultivars “Jing 411” and “Xiaoyan 54” were studied by comparing the difference in spectroscopic properties. It was found that high light intensity caused the damage of pigments in PSⅠ, especially Chl a molecules with maximum absorption at 683 nm is very sensitive to high light. The change in fluorescence spectra revealed that photodamage also led to the damage of the process of energy transfer in PSⅠ. In the PSⅠ particles “Xiaoyan 54”, the absorption of Chl a molecules at 683 nm slightly decreased at the beginning of illumination and meanwhile the fluorescence become stronger, but the absorption become stable rather long, and declining after 40 min. On the other hand, PSⅠ particles of “Jing 411” showed no such changes during the process of photodamage. Presumably in PSⅠ of “Xiaoyan 54”, excessive energy was distributed to long wave chlorophyll molecules and the number of antenna pigment molecules was less, so that less energy was transferred to the reaction center P700 and thus it was protected. This is the possible reason why “Xiaoyan 54” was more resistant to photooxidation.

不同品种小麦PSI颗粒光抑制过程的光谱学比较研究
郁飞¹  唐崇钦^1* 辛越勇¹ 彭德川¹ 李良璧¹  匡廷云¹ 李振声²

（1. 中国科学院植物研究所光合作用基础研究开放实验室，北京100093；2. 中国科学院遗传研究所，北京100101）

Key words: wheat, phtotosystem Ⅰ, photoinhibition, absorption spectra, fluorescence spectra, long wavelength chlorophyll