Differentiation of tissues - root apex, Biology

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.

Posted Date: 1/24/2013 1:16:46 AM | Location : United States







Related Discussions:- Differentiation of tissues - root apex, Assignment Help, Ask Question on Differentiation of tissues - root apex, Get Answer, Expert's Help, Differentiation of tissues - root apex Discussions

Write discussion on Differentiation of tissues - root apex
Your posts are moderated
Related Questions
Figure  shows part of a DNA molecule (a) (i) What do the dotted lines in Figure represent?  (ii) Name J to M. J.............................. K..............................

Q. What are the modes of transmission, main signs and symptoms and treatments of hepatitis B? The Hepatitis B is a disease caused by a DNA virus. The transmission is by blood (

Define Inhibitors and Enhancers - absorption of dietary iron? Phytates and fibre from whole grain cereals, tannins and polyphenols in tea, oxalates in green leafy vegetables li

How is the nervous system of nematodes organized? Where are the neural chords located in their body? Roundworms have a ganglial nervous system with an anterior neural ring sho

Describe Pharmacologic Agents in amyl nitrite ? Amyl Nitrite : It produces vasodilatation which initially results in marked fall in BP and in the next 30-60 seconds there is

What do you mean by Zoological Nomenclature? This trust is housed in the British Museum, London and is responsible for some of the most important literature in Zoological Nomen

All tissues have some capability for synthesis of the non-essential amino acid remodeling, amino acids and conversion of non-amino acid carbon skeletons into amino acids and other

Determine Energy Density of Human Milk? The energy density of human milk depends on the relative proportions of protein, fat and the principal carbohydrate, lactose. Lactose co

what is the excretory organ of agama lizard

Illustrate the metabolism of cornea? Metabolism of Cornea: The corneal epithelium plays several roles in the process of image formation. Its apical cell border interacts