Root Hairs

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Root Hairs


(pili radicales), outgrowths of the cells of the surface tissue (epiblem) of the absorption zone of a root.

Root hairs contain the parietal layer of protoplasm, the nucleus, and a large vacuole of the epiblemic cells. Their thin mucous walls, readily penetrated by water, stick to clumps of soil, releasing various substances into the soil that convert poorly soluble compounds into forms that are readily assimilable by the plant. Other of these substances aid the development of microflora. The root hairs also serve to support the growing tip of the root.

Root hairs are short-lived, usually dying off in 15–20 days. Their length varies in different plants from 0.06 to 10 mm. On the other hand, the total length, surface, and number of root hairs in a single plant can reach significant quantities (for example, the overall length in a wheat plant is about 20 km). With increased moisture in the soil and poorer aeration, the formation of root hairs slows, and they fail to form at all in very dry soil. Many aquatic and mycotrophic plants (for example, pines and beech) lack root hairs.


References in periodicals archive ?
The plasma membrane of growing root hairs is composed of zones of local differentiation.
The root surface area, including that of root hairs, in order to express Imax per cm2 divided the influx measured in the field mol cm-1s-1.
Several workers have reported that nodule formation precede plant growth and root hair formation [11, 15].
Both taproot and fibrous root systems increase their surface areas many times by the production of root hairs.
In related work, Gorski is homing in on genetic differences that may explain the widely varying ability of eight different Listeria strains to successfully colonize root hairs of alfalfa sprouts--and to resist being washed off by water.
Even faint traces of these substances prompt dramatic calcium movements within the root hairs.
Just behind the zone of cell division is a zone of cell elongation and then a zone where root hairs are present.
dense tangles of root hairs strangling one another.
To explain this principle will mean delving into a little physics and chemistry, but you will then easily see the unbalanced nutrition created in chemical fertilized plants Note: The colloidal humus particles are the convoys that transfer most of the minerals from the soil solution to the root hairs.
roots simple; shoot-borne roots thick; root hairs present.
The key parts of the root are the primary root, secondary root, root hairs, and root cap.
The Rhizobium form nodules in root hairs and fix gaseous nitrogen ([N.