Chlorophyll a formation in etiolated rye seedlings as dependent on the concentration of infiltrated chlorophyllide b

The accumulation of phytol pigments in leaves of etiolated rye (Secale cere ale I,.) seedlings infiltrated with chlorophyllide b (Chlide b) was studied . The Chlide b concentration ranged from 0.1 to 0.8 mM. In these leaves, bo th chlorophyll a (Chl a) and chlorophyll b (Chl b) were synthesized in dark ness. The total content of these pigments increased linearly with increasin g the exogenous Chlide b concentration in the infiltrated solution. The fra ction of Chi a in the total pool of phytol pigments decreased, while its ab solute content tended to attain a constant level. Chi a accumulation procee ding at the expense of esterification of exogenous Chlide a was not limited . Possible regulatory mechanisms of Chi a accumulation from the exogenous C hlide b in etiolated seedlings are discussed.