Plasmodesma

The structure of a primary plasmodesma. CW=cell wall, CA=callose, PM=plasma membrane, ER=endoplasmic reticulum, DM=desmotubule, Red circles=actin, Purple circles and spokes=other unidentified proteins[1]

Plasmodesmata (singular: plasmodesma) are microscopic channels which traverse the cell walls of plant cells[2] and some algal cells, enabling transport and communication between them. Plasmodesmata evolved independently in several lineages,[3] and species that have these structures include members of the Charophyceae, Charales, Coleochaetales and Phaeophyceae (which are all algae), as well as all embryophytes, better known as land plants.[4] Unlike animal cells, almost every plant cell is surrounded by a polysaccharide cell wall. Neighbouring plant cells are therefore separated by a pair of cell walls and the intervening middle lamella, forming an extracellular domain known as the apoplast. Although cell walls are permeable to small soluble proteins and other solutes, plasmodesmata enable direct, regulated, symplastic transport of substances between cells. There are two forms of plasmodesmata: primary plasmodesmata, which are formed during cell division, and secondary plasmodesmata, which can form between mature cells.[5]

Similar structures, called gap junctions[6] and membrane nanotubes, interconnect animal cells[7] and stromules form between plastids in plant cells.[8]

  1. ^ Maule, Andrew (December 2008). "Plasmodesmata: structure, function and biogenesis". Current Opinion in Plant Biology. 11 (6): 680–686. Bibcode:2008COPB...11..680M. doi:10.1016/j.pbi.2008.08.002. PMID 18824402.
  2. ^ Oparka, K. J. (2005). Plasmodesmata. Blackwell Pub Professional. ISBN 978-1-4051-2554-3.
  3. ^ Zoë A. Popper; Gurvan Michel; Cécile Hervé; David S. Domozych; William G.T. Willats; Maria G. Tuohy; Bernard Kloareg; Dagmar B. Stengel (2011). "Evolution and Diversity of Plant Cell Walls: From Algae to Flowering Plants" (PDF). Annual Review of Plant Biology. 62: 567–590. doi:10.1146/annurev-arplant-042110-103809. hdl:10379/6762. PMID 21351878. S2CID 11961888.
  4. ^ Graham, LE; Cook, ME; Busse, JS (2000), Proceedings of the National Academy of Sciences 97, 4535-4540.
  5. ^ Jan Traas; Teva Vernoux (29 June 2002). "The shoot apical meristem: the dynamics of a stable structure". Philosophical Transactions of the Royal Society B: Biological Sciences. 357 (1422): 737–747. doi:10.1098/rstb.2002.1091. PMC 1692983. PMID 12079669.
  6. ^ Bruce Alberts (2002). Molecular Biology of the Cell (4th ed.). New York: Garland Science. ISBN 978-0-8153-3218-3.
  7. ^ Gallagher KL, Benfey PN (15 January 2005). "Not just another hole in the wall: understanding intercellular protein trafficking". Genes & Development. 19 (2): 189–95. doi:10.1101/gad.1271005. PMID 15655108.
  8. ^ Gray JC, Sullivan JA, Hibberd JM, Hansen MR (2001). "Stromules: mobile protrusions and interconnections between plastids". Plant Biology. 3 (3): 223–33. Bibcode:2001PlBio...3..223G. doi:10.1055/s-2001-15204. S2CID 84474739.