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

Difference between spermatogenesis and oogenesis, DIFFERENC E BETWEEN SPER...

DIFFERENC E BETWEEN SPERMATOGENESIS AND OOGENESIS - S.NO . SPERM A T OGENESIS OOGENESIS 1.   2.   3.

Determine the genotypes of parents, In humans, the recessive allele that ca...

In humans, the recessive allele that causes a form of red-green colour blindness (c) is found on the X chromosome. a) Determine the genotypes and phenotypes of the F1 generation fr

Define the wealth care delivery, Define the Wealth Care Delivery ? The ...

Define the Wealth Care Delivery ? The challenge that exists today in many countries is to reach the whole population with adequate health case services and to ensure their util

What is sustainable agriculture, What is sustainable agriculture? Desc...

What is sustainable agriculture? Describe the contribution of biopesticides and biofertilisers in sustainable agriculture.

What are the cnidocytes, Q. What are the cnidocytes? What is the name of th...

Q. What are the cnidocytes? What is the name of the capsule inside the cnidocyte? What are the biological functions of this structure? Cnidocytes are specific cells present in

Class arachnida of phylum arthropoda, Class Arachnida of Phylum Arthropoda ...

Class Arachnida of Phylum Arthropoda Body divided into cephalothorax and abdomen. Cephalothorax along with four (4) pairs of legs; abdomen segmented or unsegmented, with or wi

Determine the use of natural colourants, Determine the use of natural colou...

Determine the use of natural colourants The use of natural colourants is limited due to their instability, low tinctorial power or price disadvantage.  The trend towards natura

Control of air pollution, Air pollution can be controlled by two fundamenta...

Air pollution can be controlled by two fundamental ways. Preventive technique: Important measure to control air pollution Suitable fuel having low sulphur content shoul

Salts responsible for the cellular osmotic regulation, Q. What are the majo...

Q. What are the major mineral salts responsible for the cellular osmotic regulation? The main ions that act in the regulation of the osmotic pressure in tissues and cells are t

What is a biologic failure, What is A biologic Failure A biologic Fail...

What is A biologic Failure A biologic Failure can be defined as the inadequacy of the host to establish or to maintain osseointegration. The inability to establish osseoint

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