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

#title a&p, list all of the parts of a generalized cell that might be invol...

list all of the parts of a generalized cell that might be involved support movement coordination respiration digestion transportation excr production making proteins and reproducti

Can you explain plasmids, Q. What are plasmids? And what is the significanc...

Q. What are plasmids? And what is the significance of plasmids for the recombinant DNA technology? Plasmids are circular fragments of DNA that are accessories to the main bacte

Can you explain aneurysm of aorta, Q. Can you explain Aneurysm of Aorta? ...

Q. Can you explain Aneurysm of Aorta? CXR findings are an enlargement of the involved portion of the aorta. A focal dilatation may simulate a mass or adenopathy. A more general

What are three main components of cytoskeletan, What is the cytoskeleton, a...

What is the cytoskeleton, and what are three of its main components? The cytoskeleton is a network of long protein strands located in the cytosol. Three main components are

What are the major bone surfaces, Bone Surfaces:  There are four major bon...

Bone Surfaces:  There are four major bone surfaces: 1) Periosteal (outer surface of all bones) 2) Endosteal (inner surface of cortical bone) 3) Haversian (inner surface o

Aquatic biomes, If you look up a world atlas you would notice that most of ...

If you look up a world atlas you would notice that most of the earth's surface is covered by the waters of the oceans (about 71%). Beneath the water surface is a fascinating world

Explain intermediate hosts or definitive hosts, Q. What is the criterion us...

Q. What is the criterion used to classify hosts as intermediate hosts or as definitive hosts? The criterion used to categorize hosts as intermediate hosts or as definitive host

What do you understand by hypelglycemia, Q. What do you understand by Hypel...

Q. What do you understand by Hypelglycemia? Hypelglycemia (abnormally high blood sugar): Maintenance of blood glucose levels within or close to the normal range has been stress

Osmoregulation in marine non-chordate metazoans, Osmoregulation in Marine N...

Osmoregulation in Marine Non-Chordate Metazoans Studies on the osmotic pressure of body fluids of marine organisms have displayed that their internal osmotic pressure is more

Summer stratification - thermal stratification, Summer Stratification - The...

Summer Stratification - Thermal stratification Thermal stratification is fairly pronounced during the summer seasons in most lakes of the temperate (cold) regions but is rare

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