Cytology of oil–body cells in Ricciocarpus natans

Abstract

Oil–body cells in the liverwort Ricciocarpus natans are present as idioblasts and contain a single oil–body each. The limiting membrane of the oil–body has a tripartite dark–light–dark configuration. The layer facing the oil–body is thickest. Lipophilic globules are embedded in a matrix, which reacted positively for proteins, polysaccharides and lipids. The globules, which initially are minute, can coalesce to larger units, ultimately forming a single one. A peripheral layer was recognized by its different stainability. This layer was sometimes separated from the rest of the globule. Some seasonal variability was observed in the nature of the matrix and the amount of lipophilic material. The origin of the oil–body from the central vacuole was traced from the meristematic zone. The resemblance between the oil–body membrane and the tonoplast is in accordance with this origin. Smooth endoplasmic reticulum is extensively developed and seems to contribute material to the developing oil–body.

The monoicous secondarily aquatic liverwort Ricciocarpos natans as a model within the radiation of derived Marchantiopsida

“…The air in these chambers provides buoyancy such that the plants float on the water surface. As is typical of the Marchantiopsida, oil body cells are found as idioblasts (isolated cells differing from their neighbours) containing a single oil body ( Kronestedt, 1983 ), and these likely function to deter herbivory as has been described for Marchantia ( Kanazawa et al., 2020 ; Romani et al., 2020 ).…”

Endophytic bacteria discovered in oil body organelle of liverworts (Marchantiophyta)

“…Oil body organelles consist of a membrane bounding a granular stroma that hosts a variable number of oil droplets, termed oil globules 9,10 . The oil globules consist of diverse terpenes (lipids) and aromatic compounds synthesized within the oil body that accumulate over time, while the granular stroma consists of either carbohydrates, proteins, or both 9,11,12 .…”

“…The literature has referred to the structures within the stroma of the oil body as granules, likening the granules to a matrix of proteins or polysaccharides 11 . However, the granules exhibit many traits incongruent with older hypotheses.…”