root cap

[′rüt ‚kap]

(botany)

A thick, protective mass of parenchymal cells covering the meristematic tip of the root.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

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References in periodicals archive

In many species, strong asymmetrical growth in the lower scutellum and coleoptile region of the proembryo displaces the root cap and plumule away from their original basal and lateral position (Goetghebeur 1986).

Phylogeny and Systematics of Cyperaceae, the Evolution and Importance of Embryo Morphology

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.

Rhizosphere biology and crop productivity--a review

Aluminium toxicity in roots: an investigation of spatial sensitivity and the role of the root cap. J.

In vitro and in vivo studies of the effects of aluminum on wheat (Triticum aestivum L.) root cell wall peroxidases

In general, root caps of many plants are not colonized by bacteria (Foster & Bowen, 1982).

Use of Plant Growth Promoting Bacteria in Banana: A New Insight for Sustainable Banana Production

In the root cap cells, Golgi bodies are sensitive to aluminum.

Molecular physiology of aluminum toxicity and tolerance in plants

Under field drying, alignment of LB followed a trend similar to PC drying, that is, from the periphery (root cap) toward inner QC cells.

Alignment of lipid bodies along the plasma membrane during the acquisition of desiccation tolerance in maize seed. (Seed Physiology, Production & Technology)

Elmore and Bayer (1992) described the root apical meristem in perennial ryegrass as having three groups of initials: one giving rise to the root cap; one producing the cells of the epidermis and cortex; and the third, innermost set, forming the vascular cylinder.

Herbicidal effects of the dipeptide alaninyl-alanine on perennial ryegrass (Lolium perenne L.) seedlings

Mucilage layers in general on root surfaces have been studied extensively (e.g., Greaves & Darbyshire, 1972; Oades, 1978; Foster, 1982) as has the secretion from root cap cells (see Rougier, 1981; Rougier & Chaboud, 1985).

Root hairs: specialized tubular cells extending root surfaces

It was also reported that WGA-B mRNA is expressed in the root caps of seedlings.

Evaluation of Parkia pendula lectin mRNA differentially expressed in seedlings/Avaliacao de mRNA da lectina de Parkia pendula diferencialmente expressa em plantillas

"We developed a bioassay that has allowed us to determine that chemical compounds exuding from the host's roots, root caps, and root border cells induce fungal hyphal branching," Nagahashi explains.

Getting to the root of the solution

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].

RHIZOSPHERE BACTERIAL FLORA OF OKRO (HIBISCUS ESCULENTUS)