Plasmodesmata
/ˌplæzmoʊdɛzˈmɑːtə/
Definition
Plasmodesmata are microscopic channels that pass through plant cell walls and connect the cytoplasm, the living fluid inside cells, of neighboring cells. They are lined by the cell membrane and often contain a narrow strand of endoplasmic reticulum, a membrane network inside cells. Through these channels, plants move water, sugars, signals, and some proteins or RNA directly from cell to cell, unlike transport through open spaces between cells.
Function in Plants
- Cell-to-cell transport: plasmodesmata let neighboring plant cells share sugars, amino acids, hormones, and some signaling molecules, helping tissues act as a connected system rather than as isolated cells.
- Growth and development signals: They help coordinate patterns such as leaf formation, root development, and the activity of growing points by allowing developmental signals to move between cells.
- Dynamic openings: Their permeability can change. Plants may narrow or block these channels by depositing callose, a carbohydrate around the opening, to regulate transport during stress or development.
- Pathway for infection spread: Some plant viruses move through plasmodesmata to invade nearby cells, which is one reason these channels matter in plant disease biology as well as normal plant function.
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