Conversion of chlorophyll b to chlorophyll a by isolated cucumber etioplasts

Chlorophyllide b was converted to chlorophyll a when incubated with cucumber etioplasts in the presence of phytol, ATP, and MgCl2. Chlorophyll a was identified by retention time on HPLC, absorption, fluorescence, and excitation spectra. It is suggested that the interconversion of chlorophyll a and b plays a significant role in the establishment of the required chlorophyll a/b ratio during the adaptation of leaves to high and low light conditions.