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

Measurement of species diversity, The measurement of species diversity prov...

The measurement of species diversity provides an important preliminary assessment of overall biodiversity. There are many ways by which species diversity is measured i.e. species r

Explain consultant dietitians, Explain Consultant dietitians Consultant...

Explain Consultant dietitians Consultant dietitians work under contract with healthcare facilities  or  in  their own private practice. They perform nutrition screenings  for

Describe rna sequence, Q. What is the name of an RNA sequence that codifies...

Q. What is the name of an RNA sequence that codifies one amino acid? Each sequence of three nitrogen-containing basis of RNA that codifies one amino acid is called a codon. The

Explain the enriched and living culture media, Explain the Enriched and Liv...

Explain the Enriched and Living Culture Media? Enriched Media - It is used for isolation of fastidious organisms, i.e., organisms having specific and elaborate nutritional requ

Determine teh term - magnesium, Determine teh term - Magnesium  Magnes...

Determine teh term - Magnesium  Magnesium helps in translocation of carbohydrates and regulates the uptake of other nutrients, presumably by helping in the formation of phosph

Define vitamins and minerals requirement for cancer patients, Define Vitami...

Define Vitamins, Minerals and Phytochemicals requirement for cancer patients? Several vitamins particularly those of the B-group are essential to promote adequate metabolism of

Explain the spring clip model, Q. Explain the Spring clip model? The sp...

Q. Explain the Spring clip model? The spring clip model differs from the spring model in a way that the force applied is comparatively slower. This also depicts elasticity or p

Define requirements of vitamins and minerals during surgery, Define Require...

Define Requirements of Vitamins and Minerals during Surgery? Normal tissue stores of vitamins are required for the metabolism of carbohydrates and protein. Deficiency states li

Resource use of biodiversity, Biodiversity is multiple resource based offer...

Biodiversity is multiple resource based offering us a range of products, materials and services. Our survival and well being of man-kind is directly dependent on biodiversity. Biod

Aujeszky''s disease, Aujeszky's disease This is primarily a disease of...

Aujeszky's disease This is primarily a disease of pigs, which serve as the principal reservoir host. The secondary hosts include cattle, horse, sheep, goat, dog and cat but hu

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