Chloroplast development in light and in darkness was investigated in the sporophyte of the anthocerote, Phaeoceros laevis (L.) Prosk. In both light‐and dark‐grown sporophytes, chloroplasts with an elaborate inner membrane system were found in chlorenchyma cells about 3 mm from the sporophyte base. Development in the dark resulted in a net increase of the average number of grana per unit of chloroplast area and of thylakoids per granum, and a parallel diminution in the chlorophyll a/b ratio. Substantial amounts of chlorophyll were synthesized in the dark. Small, paracrystalline arrays of membranes associated with extensive thylakoid stacks were found in immature plastids of dark‐grown sporophytes. These structures disappeared during early stages of subsequent chloroplast differentiation. These results are the first indication that the anthocerotes do not require light for the differentiation of their photosynthetic apparatus. Copyright © 1987, Wiley Blackwell. All rights reserved
CHLOROPLAST DEVELOPMENT IN LIGHT‐ AND DARK‐GROWN SPOROPHYTES OF PHAEOCEROS LAEVIS (L.) PROSK. (ANTHOCEROTOPHYTA)
FIORETTO, Antonietta
1987
Abstract
Chloroplast development in light and in darkness was investigated in the sporophyte of the anthocerote, Phaeoceros laevis (L.) Prosk. In both light‐and dark‐grown sporophytes, chloroplasts with an elaborate inner membrane system were found in chlorenchyma cells about 3 mm from the sporophyte base. Development in the dark resulted in a net increase of the average number of grana per unit of chloroplast area and of thylakoids per granum, and a parallel diminution in the chlorophyll a/b ratio. Substantial amounts of chlorophyll were synthesized in the dark. Small, paracrystalline arrays of membranes associated with extensive thylakoid stacks were found in immature plastids of dark‐grown sporophytes. These structures disappeared during early stages of subsequent chloroplast differentiation. These results are the first indication that the anthocerotes do not require light for the differentiation of their photosynthetic apparatus. Copyright © 1987, Wiley Blackwell. All rights reservedI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
