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 ?
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.
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
coating of root caps in aluminum tolerance has also been proposed (Horst
After 24 h PC, LB were aligned along the plasma membrane in root cap and partially aligned in outer QC cells, but they remained scattered throughout the cytoplasm in inner QC cells (Fig.
1] fw embryo MC), LB were in the alignment process (some are aligned) in root cap cells (not shown) and outer QC cells (Fig.
Alignment of LB occurred from root cap cells toward the inner core cells either with PC or field drying.
0-mg treatment, a considerable amount of radio activity was present in the epidermal cells extending back 205 gm from the tip of the root cap (Fig.
These sheaths consist of aggregations of soil particles, mucilage, isolated cells (most likely sloughed root cap cells), root hairs (Vermeer & McCully, 1982), and microorganisms.
These bacterium-binding proteins recognize specific carbohydrate receptors which are suggested to be localized in the mucilages exuded from the root hairs and root cap (Haahtela et al.
Moreover the presence of nutritive compounds in the rhizosphere as root exudates, mucilage from root caps and sloughed-off dead root cells [16] will enhance bacterial growth than in the non- rhizosphere soil where such compounds are absent; and as a rule there is always a general increase in the microorganisms in the rhizosphere [19].