Abstract: It has been proven that the Ce content of cucumber (Cucumis sativus L. ) leaves was enhanced with the increase of CeC13 concentration in Hoagland solution. The Chl a/b ratio of cucumber leaves in the control was the same as that in the treated plant, both being 3.67. However, under lower light intensity, the Chl a/b ratio in leaves of the contral was 2.72 whereas that of the treated leaves was 2.86. It showed that only under lower light intensity Ce could decrease the contents of chlorophyll b in leaves. The authors also evidenced that Ce was able to accelerate the formation of chlorophyll-protein complexes of PS Ⅰ and 110 kD polypeptide and decrease the light harvesting complex protein and 27 kD polypeptide.

Key words: Ce, Chloroplast, Chl a/b ratio, Chlorophyll-Protein complexes, Polypep-Tide