Regulation of senescence, Biology

Regulation of Senescence

Senescence is a part of a developmental sequence of events and has to be a controlled process. You must have seen that if you cut twigs having leaves and flowers and put them in flower vases, these twigs senesce faster than if the twigs were still on the parent plant. It has been found that senescence is controlled by both external and internal factors. Of the external factors, plant hormones, length of the day, temperature and nutrient supply play an important role. Of the internal factors, size and age of the plant, degree of flowering and time of ripeness of fruits determine the onset of senescence. In one experiment where the normal time of senescence was 120 days, when mature fruits were removed from plants the time of senescence was delayed.

It occurred after 140 days. And when young fruits and-flowers were removed from plants as soon as they were formed, the senescence was delayed to 160 to 180 days. This means that the senescence is initiated as soon as the process of reproduction is set in. This is probably because a plant needs a lot of nutrition for the growth of flowers and fruits. So to increase the supply to fruits, the stored material from leaves and other parts is translocated to the growing fruits. The demand is so high that the fresh supply of nutrient and photosynthates cannot be replenished. It is a simple case of more demand than supply. Naturally, the system collapses. However, in the process like majority of other organisms the plant tries to ensure that the fruits mature and seeds are set so that it can continue with its progeny. It is a case of self-sacrifice by the parent plant in order to see its seeds develop properly and grow.

Posted Date: 1/17/2013 7:56:22 AM | Location : United States

Related Discussions:- Regulation of senescence, Assignment Help, Ask Question on Regulation of senescence, Get Answer, Expert's Help, Regulation of senescence Discussions

Write discussion on Regulation of senescence
Your posts are moderated
Related Questions
Q. Type specimen of class enteropneusta? Examine the specimen and note the following features: 1. Balanoglossus has a soft, elongated, worm-like body which has a ciliated surf

Explain what is Fungi? The fungi are spore-bearing eukaryotic organisms without chlorophyll and having absorptive nutrition. These reproduce sexually as well asexually. Primari

State in brief about the nuclear DNA The nuclear DNA is distributed between two or more chromosomes, the number of which varies among different eukaryotes, and is characterist

What is Energy ? Energy Energy is defined as the capacity to do work. Work is defined as the movement of a mass, or the product of the force and the distance through which t

Q. Emergency treatment of diarrhoea? Emergency treatment and drug treatment: Severe dehydration is fatal and requires intravenous fluids and hence hospitalization. You have re

What are respiratory pigments? What is the respiratory pigment present in some arthropods? Which is the analogous molecule in humans? Respiratory pigments are molecules able t

Illustrate about the Principle of Context A third principle guiding the neuropsychological assessment of children is that environment contexts help to constraint and determine

Distinguish between epithelial and connective tissues with respect to their cell arrangement? PROVIDE a specific example (for both tissue types) of how the arrangement of cells hel

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

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