Cytokinins - apical dominance, Biology

Assignment Help:

Cytokinins - Apical Dominance

Cytokinins are also involved in the regulation of apical dominance. Wickson and Thimann studied the interaction of cytokinins and auxins in controlling the apical dominance. They isolated and cultured pea the stem sections in nutrient media containing auxins and no auxins. In the absence of auxins growth of lateral buds was not prevented. However, if cytokinins were added along with auxins, the inhibition of lateral buds was released. Wickson and Thimann also demonstrated the effect of cytokinins on entire shoots. When the intact shoot was soaked in a solution of kinetin, growth of lateral buds occurred even in the presence of shoot apical buds.

From this observation it was inferred that apical dominance exhibited by the shoot apex was overcome by the application of cytokinins. The present concept is that apical dominance is controlled by a balance between cytokinin and auxin concentrations. Some investigators suggest the possible inhibitory influence of cytokinins on auxin production. The cytokinin application to the lateral buds may inhibit the synthesis of certain forms of IAA oxidase, normally induced by IAA translocated from the terminal bud. With the repression of IAA oxidase, the spared auxin may stimulate lateral bud growth and shoot development. In addition to the possible inhibition of IAA degradation, cytokinins may initiate a sink effect at the site of lateral buds to attract diversion of nutrients from other regions.


Related Discussions:- Cytokinins - apical dominance

Egg type, why their is different amount of yolk is present in eggs.

why their is different amount of yolk is present in eggs.

Determine the symptoms of dehydration, Determine the Symptoms of Dehydratio...

Determine the Symptoms of Dehydration? The symptoms of dehydration are: Thirst Loss of appetite Decreased urination Impaired physical performance Nau

Explain pediculosis and scabies, Pediculosis and scabies  Phthirus pubi...

Pediculosis and scabies  Phthirus pubis (pubic lice), which can be found on eyelashes, back, axillary and leg hairs as well as pubic areas, and Sarcoptes scabiei infestation (s

Azotobacter, Azotobacter Azotobacter is known to possess the following...

Azotobacter Azotobacter is known to possess the following two mechanisms to protect its nitrogenase from oxygen inhibition. Respiratory protection and Confor

Nutrition, mode of nutrition in tapeworm

mode of nutrition in tapeworm

Measurement of solar energy input-radiation instruments, Measurement of sol...

Measurement of solar energy input A variety of instruments have been designed to measure the energy of solar radiations of all wavelengths as well as of a particular range of w

What are the similarities in cloning and selective breeding, Similarities ...

Similarities  in cloning and selective breeding cloning (not transgenesis) and selective breeding both transfer whole genome both selective breeding and cloning have t

Why is iodine important for human beings, Why is iodine important for human...

Why is iodine important for human beings? Iodine is a fundamental chemical element for the proper functioning of the thyroid since it is part of the hormones produced by this g

Biology, What are the differences b/w bone and cartiledge

What are the differences b/w bone and cartiledge

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