Evidence for energy transfer from protochlorophyllide to chlorophyllide in leaves treated with δ-amino-levulinic acid

From measurement of absorption and fluorescence spectra, at -196° we found that in δ-aminolevulinic acid (ALA)-treated leaves there is an important energy transfer from protochlorophyllide ALA absorbing at 649 nm, formed during the dark period following a first flash of light, to chlorophyll(ide) produced by this flash, at least at liquid nitrogen temperature. We also incidentally found that there is no accumulation of protochlorophyllide ALA absorbing at 649 nm at -5°. These facts are discussed in connection with the scheme proposed by Sundqvist. © 1974.