Callose

Callose is a plant polysaccharide, it is made by the Glucan Synthase-Like gene (GLS) in various places within a plant. Callose is composed of glucose residues linked together through β-1,3-linkages, and is termed a β-glucan. It is thought to be manufactured at the cell wall by callose synthases and is degraded by β-1,3-glucanases. Callose is very important for the permeability of plasmodesmata (Pd) in plants; the plant’s permeability is regulated by plasmodesmata callose (PDC). PDC is made by Callose Synthases and broken down by β-1,3-glucanases (BGs). The amount of callose that is built up at the plasmodesmatal neck, which is brought about by the interference of callose synthases (CalSs) and β-1,3-glucanases, determines the conductivity of the plasmodesmata[1].

Formation and function

Callose is laid down at plasmodesmata, at the cell plate during cytokinesis, and during pollen development. Callose is produced in response to wounding, infection by pathogens,[2] aluminium, and abscisic acid. When there is wounding in the plant tissue, it is fixed by the deposition of callose at the plasmodesmata and cell wall; this process happens within minutes after damage. Even though callose is not a constitutional component of the plant’s cell wall, it is related to the plant’s defense mechanism[3]. Deposits often appear on the sieve plates at the end of the growing season.[4] Callose also forms immediately around the developing meiocytes and tetrads of sexually reproducing angiosperms but is not found in related apomictic taxa.[5] Callose deposition at the cell wall has been suggested as an early marker for direct somatic embryogenesis from cortical and epidermal cells of Cichorium hybrids.[6]

See also

References

  1. De Storme N, Geelen D (2014). "Callose homeostasis at plasmodesmata: molecular regulators and developmental relevance". Frontiers in Plant Science. 5: 138. doi:10.3389/fpls.2014.00138. PMC 4001042. PMID 24795733.
  2. Nowicki M, Lichocka M, Nowakowska M, Kłosińska U, Kozik EU (January 2012). "A Simple Dual Stain for Detailed Investigations of Plant-Fungal Pathogen Interactions". Vegetable Crops Research Bulletin. 77 (1). doi:10.2478/v10032-012-0016-z.
  3. Chen XY, Kim JY (June 2009). "Callose synthesis in higher plants". Plant Signaling & Behavior. 4 (6): 489–92. PMC 2688293. PMID 19816126.
  4. Hemsley AR, Bell PR (2000). Green plants : their origin and diversity (2nd ed.). Cambridge: Cambridge University Press. ISBN 978-0-521-64109-8.
  5. Carman JG, Crane CF, Riera-Lizarazu O (1991). "Comparative Histology of Cell Walls during Meiotic and Apomeiotic Megasporogenesis in Two Hexaploid Australasian Elymus Species". Crop Science. 31 (6): 1527. doi:10.2135/cropsci1991.0011183X003100060029x.
  6. Dubois T, Guedira M, Dubois J, Vasseur J (May 1990). "Direct Somatic Embryogenesis in Roots of Cichorium: Is Callose an Early Marker?". Annals of Botany. 65 (5): 539–545. doi:10.1093/oxfordjournals.aob.a087967.
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