Distribution of Chlorophyll Intermediates with incompletely Reduced Side Chains in the Photosynthetic Chlorophyll-Protein Complexes of Rice Mutants

抄録

The distribution of chlorophyll intermediates in the rice mutant plants M249 and M134 that accumulate chlorophyllides a and b esterified with incompletely reduced alcohols, such as geranylgeraniol, dihydrogeranylgeraniol and tetrahydrogeranylgeraniol, were determined in five chlorophyll-protein complexes and free pigment resolved by non-denaturing polyacrylamide gel electrophoresis. The a/b ratios of chlorophyll intermediates in mutant thylakoids were similar regardless of reduction state of chlorophyll moieties. In light harvesting complexes and photosystem II core proteins of the rice mutants, the proportions of the intermediates in total chlorophylls were nearly constant. However, the proportions of chlorophyll-geranylgeraniol in P700-chlorophyll a-protein complexes of mutants were clearly lower than those in photosystem II core and antenna complexes. These results suggest that chlorophylls with less-reduced side chain are unlikely to be incorporated into photosystem I core protein complex, and that other photosynthetic protein complexes, such as P680-chlorophyll a-protein complex and light harvesting complexes, are independent of reduction state of the side chain.