Iaa stimulates cell enlargement, Biology

IAA Stimulates Cell Enlargement

Cell wall contains layer of cellulose fibrils and are normally quite rigid. Thus for a cell to grow, there must be a mechanism for relaxing the cellulose fibrils. IAA releases the cross linking bands which hold the micro fibrils together. Auxin is thought to cause the walls to become plastic and them osmotic water intake causes the cell to swell like a balloon. American physiologist P.M. Ray has observed that IAA effect on elongation begins after a lag period of only 8-12 minutes, in tissues as coleoptiles. Recently it has been found that with certain auxins or even with IAA itself when used under correct conditions, the lag period can be reduced to 1 minute or less.

These effects are now considered to be as a result of activisation of proton pumps in membrane that pump protons in cell wall and cause a rise in acidity. Acidification loosens bonds in cell wall and cell wall plasticity increases. This rapid response is followed by activation of m-RNA translated into enzymes that catalyze synthesis of cellulose and other cell wall materials which cause the strengthening of elongated cell wall completing the cell elongation.

Posted Date: 1/24/2013 2:33:54 AM | Location : United States







Related Discussions:- Iaa stimulates cell enlargement, Assignment Help, Ask Question on Iaa stimulates cell enlargement, Get Answer, Expert's Help, Iaa stimulates cell enlargement Discussions

Write discussion on Iaa stimulates cell enlargement
Your posts are moderated
Related Questions
The basic parts of RNA are the same than for DNA with two major differences. The pyrimidyne base uracil exchange thymine and ribose replace deoxyribose see the sugar, pyrimidines a

what arr the economic importance of phylum protozoa

What ions must a plant obtain from the soil in order to make (a) ATP, (b) chlorophyll?   (a) To create ATP (adenosine triphosphate) a plant requires a supply of phosphate io

FUNCTION S - (a) It is antagonistic to glucagon. Insulin decreases the level of glucose in the blood. It acts by increasing the rate at which glucose is transported out of the

Congenital Heart Diseases   Congenital heart diseases are classified in many ways. One set of classification is cyanotic and acynotic conditions. Morphological classification

Cilia and Flagella – Protozoans Cilia and flagella basically have a similar structure and distinction between the two on structural basis does not exist. There is a filament o

Define the term - magnetoencephalography A variant ERP known as magnetoencephalography (MEG) has been developed. MEG, which is still in its infancy, requires upward of 60 elect

A fifth member of the monoamine transmitter group is histamine. That release histamine as their neurotransmitter is located in the hypothalamus and project to cerebral cortex, lim

Amount of intracellular chloride ions in neuron A Neuron A is a healthy neuron with all the usual ion channels.  When at rest with a membrane voltage of R millivolts, neuron A

a) In what ways do farmers try to improve the quality of (i) their soil, (ii) their crop plants?    b) What other steps do farmers take to maximise the yield from their