ELECTRON OPAQUE CONTENTS OF THYLAKOIDS IN CHLOROPLASTS OF TANSY
TANACETUM VULGARE L.
G. A. Semenova
Institute of Theoretical and Experimental Biophysics, RAS, 142290 Pushchino, Moscow region,
Russia;
An intrathylakoid electron opaque substance, further referred to as loculin, is found in 80-90 % of thylakoids
of tansy leaf mesophyll chloroplasts at the stage of flower bud formation and flowering. Upon conventional isolation of
chloroplasts in aqueous solution, and fixation in osmium solution alone, loculin is not retained in thylakoids. Preliminary
fixation of leaves in glutaraldehyde makes it possible to isolate chloroplasts without injuring the envelope and stroma
(glutar chloroplasts), and loculin is retained in thylakoids under these conditions. Upon prolonged incubation of glutar
chloroplasts (for 24 h), loculin leaves thylakoids in the form of drops concentrating on the chloroplast envelope. Upon
crossing the thylakoid membrane and chloroplast, loculin properties remain unchanged. It is assumed that loculin is an
important metabolite necessary for active growth.
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