Root Cap


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root cap

[′rüt ‚kap]
(botany)
A thick, protective mass of parenchymal cells covering the meristematic tip of the root.

Root Cap

 

the protective formation (effective primarily against mechanical damage) on the growing tip of a root.

The root cap is a small (about 0.2 mm, or, rarely, in aerial roots, up to several mm) conical cap covering the tender cells of the root apex and part of the root’s growth zone. It differentiates in the earliest stages of root development from cells composing the calyptrogen (for example, in grasses and other monocotyledons) or from the apical meristem of the root (in many dicotyledons and gymnosperms). The root cap is composed of a complex of living parenchyma cells with thin mucilaginous membranes and mobile starch grains (statoliths) that are important in the geotropical reaction of the root. The outer layers of cells of the cap separate easily, and during friction with soil particles they are sloughed off, easing the root’s passage through the soil. In water plants the root cap may be reduced and be replaced by a root pocket (as in duckweed, frogbit, and water chestnut).

R. P. BARYKINA

References in periodicals archive ?
However, root caps were heavily colonised by bacteria, and contact points with remnant roots had more filamentous bacteria than other regions.
Nagahashi G, Douds DD Jr (2004) Isolated root caps, border cells, and mucilage from host roots stimulate hyphal branching of the arbuscular mycorrhizal fungus, Gigaspora gigantea.
An ultrastructural study of the inhibition of mucilage secretion in the wheat root cap by aluminium, Pp 779-787 in Plant-soil interactions at low pH (R.
Aluminium toxicity in roots: an investigation of spatial sensitivity and the role of the root cap.
aluminum-induced mucilage release from the root cap border cells can
potential depolarization of root cap cells precedes aluminum tolerance
These sheaths consist of aggregations of soil particles, mucilage, isolated cells (most likely sloughed root cap cells), root hairs (Vermeer & McCully, 1982), and microorganisms.