Abstract
Chlorophyll a and b are synthesized by at least 17 different enzymes in land plants. Among the genes encoding these enzymes, only that for divinyl-protochlorophyllide reductase has not been identified. On the other hand, Chlorophylls are degraded by at least 7 different enzymes, among which three have not been identified. In order to identify these genes, we developed an HPLC-based method to screen for Arabidopsis mutants that have defects in chlorophyll metabolism. We grew approximately 2000 EMS-mutagenized M2 seedling on vermiculite for 3 weeks and analyzed their pigment compositions by HPLC. Then, we transferred the plants in darkness for 4 days and compared their pigment compositions to those before dark treatment.
We isolated several mutants that accumulate or lack some intermediate molecules of the chlorophyll metabolism, including one that accumulate divinyl-chlorophylls.
