Chlorophylls and carotenoids in a fully habituated nonorganogenic callus of Beta vulgaris

A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll (Chl) nor carotenoid (Car). It accumulated some Car in the dark. Fluorescence spectra indicated that this H callus also accumulated some protochlorophyllide which, however, was not well integrated into the protochlorophyllide-NADPH-photoreductase complex, and therefore not transformed into chlorophyllide in the light. The H callus showed no variable fluorescence which indicated absence of photosynthesis, and therefore it suggested a full heterotrophic behaviour of this peculiar callus line. A green hormone-dependent callus of the same sugar beet had normal fluorescence spectra and kinetics comparable to those of a green leaf. © 1994 Institute of Experimental Botany.