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

Pharmacological management, Once the decision to start drug treatment of hy...

Once the decision to start drug treatment of hypertension is made, the aim should be to provide 24 hour BP control, with agents that would encourage patient adherence. The patient

Difference between plants and animals, DIFFERENCE BETWEEN PLANTS  AND ANIM...

DIFFERENCE BETWEEN PLANTS  AND ANIMALS - S . N o . C h a ra c ter P l an ts A n i m al s 1 Nutrition

What do you mean by periodical, Q. What do you mean by Periodical? A pe...

Q. What do you mean by Periodical? A periodical is a publication appearing at regular intervals. Each issue is called a number and collectively these numbers comprise a volume.

How to explain the high level of radiation resistance, Deinococcus radiodur...

Deinococcus radiodurans is a bacterium that was isolated from cooling ponds in and around nuclear power plants. It is highly resistant to ionizing radiation. Propose a hypothesis t

What the enzymes do to reaction, What do enzymes do to a reaction? Indicate...

What do enzymes do to a reaction? Indicate all that are correct. a. Lower the activation energy b. Reverse the equilibrium c. Lower the equilibrium d. Increase the reac

Nitrogen fixation and assimilation processes, what is the difference betwee...

what is the difference between nitrogen fixation, nitrification ,assimilation and denitrification processes

Define formation of healthy food habit - combat from obesity, Define Format...

Define Formation of healthy food habit - combat from obesity? Discarding faulty habits as early as possible. Most food habits formed at this age are for a life time. Special c

Planning and implementation of nursing care - haemophilia, Planning of Nurs...

Planning of Nursing Care Prevent and control  bleeding. Administer replacement therapy of factor VIII and IX as advised.  Educate and support the patient and family.

Skeleton, how they are joints to each other

how they are joints to each other

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