The Formation of Chlorophyll A in Etiolated Oat Seedlings

Abstract

The pigments in the shoots of 2.5-day old Avena seedlings which had been completely dark-grown and in the shoots of similar seedlings which had been irradiated for two hours with monochromatic blue (4358 A) light were extracted with acetone and transferred to ethyl ether. Absorption spectra of these ether extracts and of an ether solution of pure chlorophyll a are compared. There was a ten-fold increase in an absorption maximum at 6640 A following irradiation, due to the production of chlorophyll a. Chlorophyll b was apparently absent from the extracts, since there was no shoulder on the absorption curves at the chlorophyll b maximum at 6425 A.