Two types of linear structures have been seen in plant cytoplasm, largely by phase-contrast microscopy. Microscopic fine threads, o.Iμ to Iμ in diameter, were revealed in hair cells, where they formed endoplasmic systems along streaming pathways in the parietal cytoplasm and in transvacuolar strands. During circulation streaming, small plastids and mitochondria-like particles were observed moving along the fine threads. Similar fine threads, together with small plastids and mitochondria-like particles occurred in phloem exudate and transcellular microscopic strands. The transcellular strands, Iμ to 7μ in diameter, were seen in sieve-tube elements, phloem parenchyma, border parenchyma, and cortical cells. The movement of small plastids across end walls in border-parenchyma cells, the appearance of the same structures within strands in phloem cells, and the undiminished occurrence of small plastids in successive drops of phloem exudate are collectively taken as evidence for their participation in translocation. Particle movement is thought to occur through transcellular strands in association with fine threads, and to be motivated by a transcellular form of protoplasmic streaming.
Copyright (C) 1962, Society for Experimental Biology
In order to set up a list of libraries that you have access to,
you must first login
or sign up.
Then set up a personal list of libraries from your profile page by
clicking on your user name at the top right of any screen.