A COMPARATIVE, TRANSMISSION-ELECTRON MICROSCOPIC STUDY ON THE FORMATION OF OIL-BODIES IN LIVERWORTS

抄録

  In liverworts, oil-bodies represent the last developmental stage of a subcellular secretory system composed of a single or several bags originating from dilation of ER cisternae, in which proteins, mainly enzymes, accumulate before the secretory phase which begins with the rupture of the transitory connections between the nascent oil-body and ER. At this time, a part of the proteic material has given a highly refractive and osmiophilic deposit at the inner side of the limiting membrane which unambiguously distinguishes the young oil-body from other cell structures bounded by a single unit membrane, especially vacuoles. The essential oil produced within oil-bodies is composed of terpenoids or aromatic compounds or is a mixture of both.

  From available data and structural observations on fourteen newly investigated liverworts, no significant difference in the origin or development of oil-bodies has been found and there is no clear evidence for the contribution of a structural system different from ER in the differentiating oil-bodies. Ocelli from Marchantiales bear chloroplasts as those from Jungermanniales and the single oil-body results from the differentiation of only one large bag.