Effect of mercury and cadmium on photochemical activity and polypeptide compositions of photosynthetic membranes from winter bud of Brasenia schreberi
Hg、Cd对莼菜越冬芽光合膜光化学活性及多肽组分的影响

The effects of Hg 2+ and Cd 2+ on chlorophyll contents, chlorophyll a/b values, absorption spectra, fluorescence emission spectra at room temperature, electron transport activity of photosystem and polypeptides compositions of thylakoid membrane from winter bud of hydrophyte Brasenia schreberi were investigated. The results showed that the chlorophyll content and photochemical activity decreased progressively with an increasing in concentrations of Hg 2+ and Cd 2+ . The effects of Hg 2+ and Cd 2+ on the chlorophyll content and photochemical activity of thylakoid from leaves decreased obviously and the thylakoid membrane polypeptide compositions was defraded. It was also shown that toxic effects of Hg 2+ on Brasenia schreberi winter bud was more significannt than that of Cd 2+ .