Aba - dormancy, Biology

ABA - Dormancy

Abscisic acid functions as an antagonist of all three promoters like IAA, GAS and Cytokinins. ABA nullifies the activity of GA, IAA and cytokinin right by

a) Repressing the genes

b) By inhibiting the synthesis of enzymes at translation level (of those enzymes to be promoted by IAA, GA, Cytokinins);

c) By promoting enzymes involved in abscission, dormancy etc.

Some seeds are shed before the embryo has developed sufficient size or maturity for it to start growing. In this case, the seed may be dormant for a period because of the immaturity of the embryo. All these dormant systems seem to share essentially the same mechanism of dormancy-short days somehow promote the synthesis of ABA, through the agency of a phytochrome-mediated system and long days prevent the onset of dormancy. In certain cases, it also seems likely that shortage of nutrients or changes in the balance of hormonal constituents can bring about dormancy. Leopold's group has pointed out that the dormant condition is considered to be one in which the metabolic machinery of the cells lies idle because of a repressed condition of the nucleic acid system.

Posted Date: 1/24/2013 2:38:34 AM | Location : United States







Related Discussions:- Aba - dormancy, Assignment Help, Ask Question on Aba - dormancy, Get Answer, Expert's Help, Aba - dormancy Discussions

Write discussion on Aba - dormancy
Your posts are moderated
Related Questions
Expressed sequence tag (EST) is the short part of DNA sequence of corresponding to the fragment of the complementary DNA (made from the cell's messenger RNA). ESTs have been taken

Q. Complications in celiac disease? Patients with severe form of celiac's disease for long period are at risk for several complications mainly due to nutrient absorption probl

What are the situations in which the environment can change the genotype of an individual? What is the condition for this type of change to be transmitted to the offspring? The

What is the main theory opposed to evolution? The major theory that opposes the evolution theory on the explanation of how species emerged (phylogenesis) is fixism.

Q. What is gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers? Gastrulation is the process through which a portion of the bl

Define Carbohydrate requirement for cancer patients? Adequate amount (60% of total energy) of carbohydrates should be provided. If a very high calorie diet is being given, emph

Explain Risk Assessment Risk Assessment   :  The scientific evaluation  of  known  or  potential adverse  health effects  resulting  from  human exposure to food borne hazards

Bone Density The compact bone surrounding dense evenly spaced trabeculae with small cancellous spaces is ideal/suitable for implant placement. Dense or porous cortical bone is

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4