Cytokinins - apical dominance, Biology

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.

Posted Date: 1/24/2013 3:06:08 AM | Location : United States







Related Discussions:- Cytokinins - apical dominance, Assignment Help, Ask Question on Cytokinins - apical dominance, Get Answer, Expert's Help, Cytokinins - apical dominance Discussions

Write discussion on Cytokinins - apical dominance
Your posts are moderated
Related Questions
Relapse of infective endocarditis usually occurs within two months of the discontinuation of antimicrobial therapy. The relapse rate for patients with native-valve endocarditis cau

Define HOCM Murmur characteristics in details? Characteristics: The murmur is harsh, crescendo-decrescendo audible along the left sternal border, radiates to the base of heart

Nature and Distribution of Viruses Although several infectious diseases of animals and plants had been found to be caused by viruses during early 20 th century, the true natur

Determine the term - Epilepsy In epilepsy, a person suffers from recurrent seizures of various types that register on an electroencephalogram and are associated with disturbanc

Q. What are the types of antigenic agents that may constitute vaccines? Vaccines can be constituted of dead agents of disease, of inactivated toxins, of inactivated agents of d

Less than ideal Primary Stability Faulty osteotomy (a bigger osteotomy than required for the selected diameter of implant) can result when excessive force is used to disengage

Explain the Management of Eating Disorders? We shall consider the components of the management of anorexia nervosa and bulimia nervosa together, since the nutritional consequen

order of the phylum protozoa

List and briefly describe the mechanisms that prevent acid-base imbalances from appearing in the body. In addition, indicate where each mechanism functions most significantly.

What are autotrophic beings? What are heterotrophic beings? Autotrophic beings are those that can make their own food, i.e., that make organic material from inorganic compounds