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 ritonavir, Ritonavir (RTV, Norvir)  Ritonavir is well absorbed ...

Ritonavir (RTV, Norvir)  Ritonavir is well absorbed  from the gastrointestinal tract and at full doses potently inhibits HIV, but due to poor tolerability it is now used mainly

Birth marks (naevi) and vascular naevi, Birth Marks  (Naevi): Birth Ma...

Birth Marks  (Naevi): Birth Marks  is also known  as naevi.  It  is a multiplication  of  one or more cutaneous elements within  the skin. It  is defined  as a  congenital, ci

Enzyme - linked immunosorbent assay (elisa), E n z y m e - l...

E n z y m e - linked immunosorbent assay (ELISA):   ELISA in its var io us modifications e.g. plate ELISA, sandwich ELISA, competitive ELISA, ELISA strip or

List the reactions that need to be circumvented, List the reactions that ne...

List the reactions that need to be circumvented by the special reactions in gluconeogenesis. The reactions that are circumvented  include: Between pyruvate and phosphoenolpy

Define how to prevent the cancer, Define How to Prevent the Cancer? A c...

Define How to Prevent the Cancer? A continuing and urgent need is there to take all steps to prevent cancer. Cancer rates are set to increase another 50 percent by the year 202

What percentage of the offspring will have purple flowers, Purple(P) flower...

Purple(P) flowers are dominant and white(p) flowers are recessive. A homozygous dominant purple flower is crossed with a homozygous recessive white flower. what percentage of the o

Define eye balling, Q. Define Eye Balling? Ans. Two-dimensional ec...

Q. Define Eye Balling? Ans. Two-dimensional echocardiography provides a good visual perception of cardiac functions. With experience, the echocardiologist learns to percei

Define the foam mat drying method, Define the Foam Mat Drying Method? T...

Define the Foam Mat Drying Method? This process is a development of the vacuum puffing but, instead of employing a vacuum to foam the material, it is initially foamed by suitab

Slight or no metamorphosis, Slight or no Metamorphosis In primitive w...

Slight or no Metamorphosis In primitive wingless insects (Apterygota) such as spring tails, silver fish etc. and in secondarily apterous insects the young ones which hatch fr

What is primary growth in shoot, What is Primary Growth in Shoot? The ...

What is Primary Growth in Shoot? The growth in height of a plant stem results from the division of cells at the apex, or tip of the stem, called the shoot tip. Here, a group o

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