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

Morphology, Morphology:  It deals with external forms, structure and the re...

Morphology:  It deals with external forms, structure and the relative position of various organs of living beings. Morphology is a branch of bioscience which dealing with the study

What are the three qualities specific to colour vision, What are the three ...

What are the three qualities specific to colour vision There are three qualities specific to colour vision- hue, saturation, and brightness. Hue: Hue is the function of a wa

Explain the interaction of vitamin a with zinc, Explain the interaction of ...

Explain the interaction of vitamin a with Zinc? Its deficiency interferes with vitamin A metabolism. It leads to a reduction in the synthesis of plasma proteins, particularly,

What is stage 2 implant surgery, Stage 2 implant surgery After evaluati...

Stage 2 implant surgery After evaluating the status of the implant, stage two procedure is carried out to bring forth a communication of the implant to the oral cavity by surgi

What do you understand by exoskeleton, What do you understand by Exoskeleto...

What do you understand by Exoskeleton. Supporting structures of skeleton not surrounded by the body. Endoskeletal elements are secreted by an underlying epidermis and one side

Theory of natural selection, What key idea, contained in Malthus's essay on...

What key idea, contained in Malthus's essay on populations, helped Darwin formulate his theory of natural selection?

Hazards of oxygen therapy - respiratory failure, Hazards of O 2 Therapy ...

Hazards of O 2 Therapy Exposure to greater than 60 per cent O 2 , for a period of more than 36 hours, or exposure to 100 per cent 0, for a period of more than 6 hours, res

Determine the categories of sleep disorders, Determine the categories of sl...

Determine the categories of sleep disorders Sleep disorders are generally divided into two major groups: 1) Narcolepsy, which is characterised by excessive sleep or brief in

Test for starch, have any picture this expiriment at record?

have any picture this expiriment at record?

Bacterial and mycotic diseases, Bacterial and Mycotic Diseases Bacteria...

Bacterial and Mycotic Diseases Bacteria and fungi are microscopic organisms which are ubiquitous in nature and are widely present in soil, fresh and salt water, air, vegetation

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