 | |
| Names | |
|---|---|
| Other names (1→3)-β-D-Glucan | |
| Identifiers | |
| ChEBI | |
| Properties | |
| (C6H10O5)n | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Callose is a plantpolysaccharide. Its production is due to the glucan synthase-like gene (GLS) in various places within a plant. It is produced to act as a temporary cell wall in response to stimuli such as stress or damage.[1] Callose is composed ofglucose residues linked together through β-1,3-linkages, and is termed aβ-glucan. It is thought to be manufactured at thecell wall by callose synthases and is degraded by β-1,3-glucanases. Callose is very important for the permeability ofplasmodesmata (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.[2]
Callose is laid down atplasmodesmata, at thecell plate duringcytokinesis, and duringpollen development. Endothecium contains a substance callose, which makes it thicker. Callose is produced in response to wounding, infection by pathogens,[3]aluminium, andabscisic 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.[4] Deposits often appear on thesieve plates at the end of the growing season.[5] Callose also forms immediately around the developingmeiocytes and tetrads of sexually reproducingangiosperms but is not found in relatedapomictic taxa.[6] Callose deposition at the cell wall has been suggested as an early marker for direct somatic embryogenesis from cortical and epidermal cells ofCichorium hybrids.[7] Temporary callose walls are also thought to be a barrier between a cell and its environment, while the cell is undergoing a genetic programming that allows it todifferentiate.[8] This is because callose walls can be found aroundnucellar embryos duringNucellar embryony.[9]