Relationships among membranes in plastids of the red algaNitophyllum punctatum (Stackh.) Grev.

Summary The fine structure of plastids in the early stages of differentiation has been studied during the carposporogenesis of the red algaNitophyllum punctatum (Stackh.) Grev. A membranous body has been found in the plastidial matrix, which shows connections either with thylakoids, or with the plastidial genophore. More than one membranous body may be present and in some instances they show a morphological relationship also with the plastidial limiting membranes. The presence of such bodies has been observed also in fully differentiated plastids in a number of other red algae currently under study.It has been shown that the plastidial envelope may release in the matrix vesicles that give rise to the single thylakoids typical of the red algal plastids.The research project received the financial support of Ministero della Pubblica Istruzione (Roma).