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 the types of basic forces, Q. Explain the types of basic forces? ...

Q. Explain the types of basic forces? Compression: This refers to the squeezing of the test material so that it still remains as a single undivided unit but may occupy less v

Explain the nutritional and functional role of sulphur, Minerals :-  Sulfur...

Minerals :-  Sulfur Food Source       Widely distributed  Nutritional Functional role Essential nutrient: A constituent of the essential amino acids methionine and

What happens to the dna molecule when the ends, Now try to pull the strands...

Now try to pull the strands apart at the "origin of replication." What happens to the DNA molecule when the ends are restricted

Illustrate the removal of carbon dioxide from the body, Which of the follow...

Which of the following processes in capillaries in the lung assist in the removal of carbon dioxide from the body? A. Net flux of carbon dioxide from red blood cells into plasm

Percussive instruments-coronal disassembly devices, Percussive instruments ...

Percussive instruments -Crown and bridge remover CORONA flex I. Nitch -it's tip look like the curette and has hock -4 or 5 tips according to tooth position and accessib

Pectin, PECTIN It consists of methylated galacturonic acid, galactos...

PECTIN It consists of methylated galacturonic acid, galactose & arabinose. It is also called plant cement becuase it binds layers of cell wall. It is a structural poly

Diversity in living organisms.., labelled diagram of male and female cockro...

labelled diagram of male and female cockroach with difference between them

Define changes in food due to concentration process, Define Changes in Food...

Define Changes in Food due to Concentration Process? Obviously concentration that exposes food to 100°C or higher temperatures for prolonged periods can cause major changes in

Chlorocruorins - respiratory pigments, Chlorocruorins - Respiratory Pigment...

Chlorocruorins - Respiratory Pigments These types of respiratory pigments are found in four polychaete families: Sabellidae, Serpulidae, Ampharetidae and Chlorhaemidae. The pi

Succession, why succession more likely to occur on valley floor than steep ...

why succession more likely to occur on valley floor than steep slopes

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