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

Name some standard activation energy, The standard free energy change and s...

The standard free energy change and standard activation energy for four biochemical reactions are listed in the table below: A few interpretations are given below. Between thes

Explain transition period from renaissance to modern period, Explain Transi...

Explain Transition Period from Renaissance to Modern Period? The transition period from the Renaissance to the Modern period produced many notable workers and much literature.

Zoology, How does classifying animals based on similarities and traits help...

How does classifying animals based on similarities and traits help future scientists

Explain the bioavailability of vitamin e, Explain the Bioavailability of Vi...

Explain the Bioavailability of Vitamin E? For dietary purposes, vitamin E activity is expressed as a-tocopherol equivalents (a-TEs). One α-TE is the activity of l mg α-tocophe

Define the future challenges of spatial processes, Define the Future challe...

Define the Future challenges of spatial processes? Understanding the dynamics of stochastic spatial systems, systems with a multitude of spatial scales, and systems along with

Explain viscosity and plasticity of colloidal particle, Viscosity and Plast...

Viscosity and Plasticity of colloidal particle Various degrees of viscosity and plasticity are encountered in colloids. Viscosity may be described as resistance to pouring.

What is ventilation, What is ventilation   A.  An increase in the hydro...

What is ventilation   A.  An increase in the hydrogen ion concentration in the interstitial spaces of the  brain stem leads to an increase in the duration of the respiratory cy

Would you expect the muscle fibers of the tongue, Would you expect the musc...

Would you expect the muscle fibers of the tongue to be striated or smooth? What about the muscle of the diaphragm/ Explain your answer.

Blood, what are the component of hemoglobin

what are the component of hemoglobin

Explain micronutrient, Which one of the following is not a micronutrient? ...

Which one of the following is not a micronutrient? 1. Molybdenum 2. Magnesium 3. Zinc 4. Boron. Magnesium

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