Differentiation of tissues - root apex, Biology

Assignment Help:

Differentiation of Tissues - Root Apex

New cells generated from the divisions of meristematic cells start expanding and differentiating further. Epidermis, cortex and stele are formed. Stele is organized into xylem forming a star shaped central axis with columns of phloem between the points of the star, encircled by the pericycle. But what are the processes that control differentiation? Certain experimental studies involving surgical removal of small portion of root tips and observing their differentiation in culture has thrown much light on root development. Smaller pieces while differentiating produced monoarch and diarch type vascular organisation even though originally the plant root showed triarch pattern. This experiment indicates that a definite size of root tip is needed for realization of its full morphogenetic potential. But on further growth even these small pieces revert back to normal pattern of organisation of vasculature. If auxin at 10-5 M concentrations was provided in the culture exarch vascular tissue was formed. The ontogenic development of the primary vascular system of the root is simple.

The differentiation of the root tissues behind the apical meristems is summarized as follows: Periclinal divisions in the cortex cease near the level where the sieve elements mature: beyond this region the root undergoes rapid elongation and the maturation of the protoxylem usually takes place when the process of elongation is almost completed: Casparian strips develop in the endodermal cells before the maturation of the protoxylem elements and also before the appearance of root hairs. Phytohormones influence the development of secondary vascular tissue. When the roots are cultured on a nutrient medium containing Indole Acetic Acid (10-5 m) along with sucrose can induce secondary vascular tissue. Cytokinins and hexitols in small amounts promote secondary vascular tissue. Roots also depend upon vitamin 'B' for their proper growth.


Related Discussions:- Differentiation of tissues - root apex

Amoeboid tapetum - tapetum, Amoeboid Tapetum - Tapetum It is also know...

Amoeboid Tapetum - Tapetum It is also known as invasive or periplus modial tapetum. This type of tapetum is more prevalent in the monocotyledons (Arum) than in the dicotyledon

Define some texturization processes, Known physicochemical basis of some of...

Known physicochemical basis of some of these texturization processes are presented below: 1.Thermal Coagulation and Film Formation: Concentrated soy proteins can be thermally

Foods to be avoided during thyphoid, Foods to be avoided are: High fibr...

Foods to be avoided are: High fibre foods like whole grain cereals and  their products (e.g. whole wheat flour, cracked wheat, whole pulses) Raw vegetables and fruits Fri

Concerning the body temperature how reptilia classify, Q. Concerning the ma...

Q. Concerning the maintenance of body temperature how do beings of the class Reptilia classify? Like amphibians and fishes, beings of the class Reptilia are heterothermic anima

Factors causing short-term changes in intra-ocular pressure, What Factors c...

What Factors causing short-term changes in intra-ocular pressure 1) Arterial blood pressure 2) Systemic venous pressure (SVP) 3) Mechanical pressure 4) Plasma osmolari

Endosperm, 1. What are the examples of helobial endosperm

1. What are the examples of helobial endosperm

Explain tertiary butylhydroquinone, Tertiary Butylhydroquinone (TBHQ) T...

Tertiary Butylhydroquinone (TBHQ) TBHQ is moderately soluble in oil and slightly soluble in water. In many cases, TBHQ is more effective than any other antioxidant in providing

Determine some food sources of chromium, Determine some Food Sources of chr...

Determine some Food Sources of chromium? Chromium occurs in trivalent form in foods. Good sources of chromium include whole grains, spices and condiments, meats especially orga

Self- vs. cross-pollination, Self- vs. Cross-Pollination A major adva...

Self- vs. Cross-Pollination A major advantage of self-pollination is its certainty. Continued self-pollination over many generations, however, results in weaker progeny. This

How does immune process that causes the hemolytic disease, How does the imm...

How does the immune process that causes the hemolytic disease of the newborn take place? In a hemolytic disease of the newborn the mother has Rh- blood and this mother when gen

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd