Plant Roots || Root Parts || CSS/PCS/PMS/IAS

Plant Roots || Root Parts || CSS/PCS/PMS/IAS

Plant Roots || Root Parts || CSS/PCS/PMS/IAS

Definition:

Generally the underground portion of the seed, which usually comes from the hibcotel, acts as a means of absorbing, distributing and storing food or as anchor and support device, and varies with the stem, especially in the absence of buds.

Primary structure of root:

Roots extract water and minerals from the soil. They penetrate the soil, growing upnelongation near the end. Since the soil is a hardy soil, the tip of the crop is close conical protective root cap that lubricates the root surface when pushed by the expansion of cells between soil particles. Growth occurs when new cells are formed in meristems in the division of elongated cells in the extension zone. The elongation is driven by the hydrostatic pressure in the cell  that drives the root tip deeper into the soil.

The elongation zone is actually cylindrical, allowing growth in soil. Behind him, in the ripening zone, root hair develop that provide large areas of contact with water and nutritional films surrounding soil particles and anchored older parts of the root. Internally ground root tissue is the bark, composed of a large vacuolate cells that fill the space between the epidermis and the vascular cylinder (stele). While all cells in the root can be traced to their origins in root merits, many key root tissues cannot be observed until form in the maturation zone.


Includes vascular package (stele) phloem (which develops first) and xylem surrounded by a cylinder of cells with waterproof cell walls, endoderm. Endodermal cells have characteristic thickening of preclinical cell walls (radial and transverse walls, which are perpendicular to the root surface). This wall is thickening, Kasparian the strip is impregnated with a water impermeable substance, suberin. Unripe xylems and endoderms can be seen below the area where root hairs form. Later, lateral roots may form above the root hair zone. They come from cells near the vascular tissue and pass through the cortex and epidermis. Each lateral root has a meristem, and its vascular tissue joins the primary root.

Root apical meristems:

Merystem is located behind the root of the root and consists of small, thin-walled cells with clear nuclei and without a large vacuole. Two types of roots have been suggested. In closed roots (for example in maize [corn], three layers of cells (initials) can be identified in one region in the apical meristem that make up all root tissues. In the other type, open roots (for example onion) appear to have three meristems that form root tissues separately.

Root cap: 

Root cap is a conical collection of parenchymal cells, which in some plants is large and visible, while in others it is small. It protects the root tip when it is squeezed through the soil and secretes mucus as a lubricant produced in the Golgi apparatus of slime-secreting cells. Seed cells have a short life span (up to 1 week, depending on the species) and are constantly removed and may remain alive in the mucus for some time. The locks provide an environment for bacteria and fungi living in the rhizosphere, in the immediate environment of the root.

Root hairs: 

Root hair is unicellular structures formed as growths of epidermal cells that form a root hair zone that provides a very large area of   contact with the soil. While root hair is usually only 0.1-1.0 cm long, it can be very numerous, with over 20,000 cm-2 root hairs and billions per plant, which gives a large surface for absorption. Root hair is also short-lived and the mature root areas are devoid of hair. The root hair zone is therefore extremely important for the uptake of water and minerals, although in plants with mycorrhizal fungi associated with root, root hairs may be much less important or absent.

Root Architecture: 

All plants first form the main root, and in most plants, including gymnosperms, primitive dicotyledons and eudicotyledones, they persist as a pile root. Lateral roots arise from it at various points. In monocotyledonous roots die and random roots are formed, which grow from the stem. They give a mass of small, fibrous roots of similar size and visibility. Root architecture always follows one of these basic plans, but also responds to soil depth, water availability, and nutrients.

Post a comment

0 Comments