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

Angiographic quantification, Angiographic Quantification Gr 1 - minimal...

Angiographic Quantification Gr 1 - minimal systolic jet, clears rapidly Gr 2 - partial RA opacification Gr 3 - Opacification of whole of RA GR4 - Opacification of

What are the sources of dietary fibre in our diet, Q. What are the sources ...

Q. What are the sources of dietary fibre in our diet? The sources of dietary fibre include whole grain cereals, legumes, whole pulses, leafy vegetables, vegetables like peas,

Handling animals in lab, Handling : The desire for survival is same whethe...

Handling : The desire for survival is same whether in animals or human beings. You may be aware of the ability of even tiny animals to scratch and bite. So we won't say any more o

What is the type of reproduction that occurs in roundworms, What is the typ...

What is the type of reproduction that occurs in roundworms? What typical element do nematode sperm cells have? Nematodes reproduce sexually. The nematode sperm cell does not h

Describe about results of total anomalous pulmonary venous, Describe about ...

Describe about Results of Total Anomalous pulmonary Venous Connection ? Reported hospital mortality varies from 2 to 20 per cent depending on the experience of cardiac surgery

Define other sex determination systems, Besides the XY system are there oth...

Besides the XY system are there other sex determination systems? A few animals have a sex determination system different from the XY system such as the X0 system is the sex det

Marine biomes, The marine biomes consist of the earth's oceans and its asso...

The marine biomes consist of the earth's oceans and its associated areas like the shorelines, islands, reefs and estuaries. The marine waters contain about 3.5 percent salt, mostly

Consequences on the bony structures, Q. Consequences on the bony structures...

Q. Consequences on the bony structures? Basal bone forms the dental skeletal structure. Wolff's law states that the bone remodels in relationship to the forces applied. With a

Determine the urine analysis, Determine the Urine analysis Urine consti...

Determine the Urine analysis Urine constituent may be altered in urinary tract infection, systemic disease. However it is not routinely prescribed for most of the potential imp

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