Towards reconciliation of structure with function in plasmodesmata—who is the gatekeeper?

Botha, C.E.J. and Cross, R.H.M. (2000) Towards reconciliation of structure with function in plasmodesmata—who is the gatekeeper? Micron, 31 (6). pp. 713-721. ISSN 0968-4328



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Whilst the structure of higher plant plasmodesmata was first described by Robards (1963. Desmotubule—a plasmodesmatal substructure. Nature 218, 784), and despite many subsequent intensive investigations, there is still much that remains unclear relating to their ultrastructure and functioning in higher plants. We have examined chemically fixed plant material, and suggest that the conformational changes seen in plasmodesmatal substructure, particularly the deposition of electron-dense extra-plasmodesmal material, is linked to either manipulation of the hormonal balance (as in Avocado fruit), or of osmotic potential in leaf blade material. These changes result in the deposition of β 1,3-glucan (callose) at the neck region of these plasmodesmata. This electron-dense material is deposited at the neck region of plasmodesmata, and forms a collar-like structure. The formation of a collar is shown to be coupled with loss of lucence within the cytoplasmic sleeve. The formation of a collar at the plasmodesmatal orifice thus results in encapsulation and closure of the plasmodesmatal orifice. Closure of the orifice coincides with a loss of electron-lucence and a lack of resolution of the desmotubule. These ultrastructural changes are potentially significant and could contribute to, result in, or assist in the down-regulation of cell to cell trafficking via plasmodesmata.

Item Type:Article
Uncontrolled Keywords:Desmotubule; Callose deposition; Neck constriction; Cell-to-cell communication; Cell-to-cell transport regulation; Plasmodesmata
Subjects:Y Unknown > Subjects to be assigned
Divisions:Faculty > Faculty of Science > Botany
ID Code:289
Deposited By: Ms Vivien Botha
Deposited On:18 Aug 2006
Last Modified:06 Jan 2012 16:17
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