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 antimicrobial prophylaxis, Explain Antimicrobial Prophylaxis An...

Explain Antimicrobial Prophylaxis Antimicrobial prophylaxis can decrease the incidence of infection, particularly surgical site infection, after certain operations, but this be

How we can measure perimplant pd, How we can measure perimplant PD Peri...

How we can measure perimplant PD Perimplant PD should be measured routinely during maintenance appointment with a less probing force (0.2 to 0.3 N) as the tissue is more sensit

What factor below contributed to the current variations, According to the t...

According to the theory of natural selection, what factor below contributed to the current variations in beak sizes of finch species on the Galapagos islands? a. Finches dispersed

Explain about the solar dryers, Explain about the Solar Dryers? There a...

Explain about the Solar Dryers? There are so many different designs for solar dryers, these range from simple convection dryers, cabinet dryers, shelf dryers to more complicate

Define interaction of vitamin k with calcium, Define interaction of vitamin...

Define interaction of vitamin k with Calcium? Since vitamin D functions have an impact on calcium metabolism, an inter-relationship exists between vitamin IS-dependent proteins

Define effect of feeding method on drug availability, Define Effect of feed...

Define Effect of feeding method on drug availability? The form in which a drug is administered or enters the body can influence its absorption, metabolism or excretion. This be

Bjork-shiley valve (b-s)-types of valves, Bjork-Shiley Valve (B-S) : This...

Bjork-Shiley Valve (B-S) : This is one of the earliest types of tilting disc valves introduced in early 70's. The earlier models like concavo-convex disc valves were withdrawn fr

Determine the concept of imitation in the learning process, Determine the c...

Determine the concept of  imitation in the learning process The concept of  imitation in the learning process is also a key developmental concept for infants and young children

Why is cannibalism an inharmonious ecological interaction, Q. Why is cannib...

Q. Why is cannibalism an inharmonious intraspecific ecological interaction? In the cannibalism an individual eats other of the same species (occurs in some arachnids and insect

Explain the term- cerebral ischemia, Explain the term- Cerebral Ischemia ...

Explain the term- Cerebral Ischemia Ischemia refers to any of a group of disorders in which the symptoms are caused by vessel blockage preventing a sufficient supply of blood t

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