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

Binomial nomenclature, Binomial Nomenclature The modern system of clas...

Binomial Nomenclature The modern system of classification (Binomial nomenclature) accepted by biologists today was proposed in 1758 by the Swedish botanist Linnaeus (1707-1778

What is fluoride inhibitor, Fluoride Inhibitor Fluoride inhibits  enola...

Fluoride Inhibitor Fluoride inhibits  enolase enzyme involved in the conversion of 2-phosphoglerate  to phosphoenol pyruvate.

What is the dichogamy, What is the dichogamy? Dichogamy is phenomenon o...

What is the dichogamy? Dichogamy is phenomenon of the maturation of female reproductive structures of the plant in a different period to the maturation of the male reproductive

How many kcal of gross energy were formed, The question asks . . . 18 moles...

The question asks . . . 18 moles of moles of maltose are completely oxidized by the reactions of the final oxidative pathways (Embden-Myerhoff Pathway and Krebs Cycle). How many AT

Aetiology, Aetiology:   A List Of The Causes Of A Disease  (Description Of ...

Aetiology:   A List Of The Causes Of A Disease  (Description Of The Characteristic Causes) Factors Which Influence The Onset Of Disease:  Include "Risk Factors", Life-Style, Sex, A

Explain process of stress testing in women, Q. Explain process of Stress Te...

Q. Explain process of Stress Testing in Women? Estrogen has been implicated as a cause of ST depression. For years it seemed that estrogen protect women from coronary artery di

Show ions used in electrical impulse transmission in neurons, Q. What are t...

Q. What are the two major ions that participate in the electrical impulse transmission in neurons? The two major ions that participate in the electrical impulse transmission in

Determine functions of zinc in the body, Determine Functions of Zinc in the...

Determine Functions of Zinc in the Body? Zinc is an essential component of a large number of enzymes participating in the synthesis and degradation of carbohydrates, lipids, pr

Which is the first heart chamber into which blood enters, Q. Which is the f...

Q. Which is the first (human) heart chamber into which blood enters? Where does the blood go after passing that chamber? What is the name of the valve that separates the compartmen

Explain cholera, Cholera  The risk of infection with cholera is very lo...

Cholera  The risk of infection with cholera is very low in tourists. The parenteral vaccine licensed in the US is no longer available. One oral vaccine called Dukoral is availa

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