Presence of Nucleus and Cytoplasm in the Mature Vessel Elements and Fibre Tracheids in Japan Jute Plants

Abstract

IT is commonly held that the mature vessel elements of plants are non-living cells. In jute¹, the cell-wall of the vessel elements is lignified and has scalariform thickening and simple pits on the lateral walls. Esau has stated : “In the mature state, tracheids and vessel members are more or less elongated cells with lignified secondary walls and devoid of protoplasts”. In a recent publication², she mentions (p. 225) : “After the secondary walls are fully formed and lignified the swollen parts of the primary wall break down (fig. 11.3,F and plate 25,D) and finally the protoplasts die and disappear”. The course of events is interpreted by Shah³ in the following way: “The disappearance and loss of the protoplast usually synchronizes with the formation of perforation plates (Eames and MacDaniels, fig. 49; Esau, figs. 11–13)”. Recently, I have described⁴ how, during the course of development of primary vessel elements, “the protoplasts disappear after the deposition of the secondary thickening matter”.