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
Radiometer Radiometer measures the flux of energy of all wavelengths received on a single surface of the receiver. There are also instruments that can measure the difference be

What are the advantages of ecological pyramids?

Thoracic (non-cardiac) Antibiotic prophylaxis is given routinely in thoracic surgery, but sup- porting data are sparse. In one study, a single preoperative dose of cefazolin be

Weight Measurement of New Born Check weight on an infant weighing machine. Weight of the neonate is 2.8-3.5 kg with an average weight of 2.5 kg. When taking weight take

Dopamine is important for working memory and drug that increases the level of dopamine in the brain or facilities the action of dopamine, enhances working memory capabilities.Dopam

Explain Adverse effects of ritonavir - Adverse reactions are common to full doses of ritonavir, but less common with the low doses used in PI combinations. Ritonavir can cause

Psychology : This is the study of human mind. On other words Psychology is the science of behavior or mental processes. Its immediate aim is to understand the individuals or groups

Define Anaemia in Pregnancy? Anaemia is the most common complication and is often compounded by low socio- economic status. However, it is seen frequently in upper income women

What is normal bone physiology An insight into the normal bone physiology and its adaptation by modeling and remodelling process to functional stresses is also of importance. I

How does substrate concentration affect the initial rate of an enzyme- catalyzed reaction?