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

Explain causes of shigellosis, Q. Explain causes of Shigellosis? Shigel...

Q. Explain causes of Shigellosis? Shigellosis is caused by the genus Shigella and is a common enteric (intestinal) infection. The genus has four serological groups,

Laws of cleavage, L A W S OF CLEAVAGE - 1. Sac's Law - According t...

L A W S OF CLEAVAGE - 1. Sac's Law - According this law, during cleavage each blastomere to form similar blastomere. New cleavae always take place at the right angle of th

Appendical skeleton, it consists of the girdles and the skeleton of the lim...

it consists of the girdles and the skeleton of the limbs

The formation of macro and micronuclei of daughter paramoeci, The formation...

The formation of macro and micronuclei of daughter paramoeci: Each exconjugant has a single micronucleus and four macronuclei. This type of exconjugant divides twice and f

Fat metabolism, FAT METABOLISM Animals  digest  and utilize three main ...

FAT METABOLISM Animals  digest  and utilize three main  types  of fatty compounds or lipids  neutral or true  fats ( triglycerides ),  phospholipids  and sterols. Endproducts

What is the significance of immunogenicity, Problem: Explain the proced...

Problem: Explain the procedure for import of cosmetics in US. - Briefly explain the procedure for import of cosmetics in US What are the major points to be considered whe

Types of transport process in sieve tubes, Types of Transport Process in Si...

Types of Transport Process in Sieve Tubes The metabolites of all the mesophyll cells around the sieve elements join in a common pool to load via the surrounding transfer cells

Explain about eukaryotic organism or fungi, Q. Explain about eukaryotic org...

Q. Explain about eukaryotic organism or Fungi? Fungi are eukaryotic organisms. This means that their DNA-containing chromosomes are enclosed within a nucleus inside their cell

Loudness, The sound levels of power, intensity and pressure are the physica...

The sound levels of power, intensity and pressure are the physical effects which the human ear receives, it is not, however, what the person perceives. What is being perceived or h

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