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
Patient X has blood plasma levels of Parathyroid Hormone (PTH) that are always very high due to a tumor consisting of Parathyroid Gland cells that secrete high levels of PTH into t

Concerning the presence of the nucleus what is the difference among animal and bacterial cells? Animal cells (cells of living beings of the kingdom Animalia) have an interior m

Define Vapor-pressure lowering and Osmotic pressure? 1. Vapor-pressure lowering: the decrease in the vapor pressure of a solution containing nonvolatile solutes, compared to th

Linkage of Health With Development Health, in its comprehensive or holistic sense, refers to the state of completephysical, mental, social and spiritual well being of a person.

Explain Magnetic Stirrer - Food Microbiology It can be used for mixing ingredients at the time of media or reagents preparation. Mixing happens with spinning of a teflon coat

Emulsions  You may have eaten Mayonnaise. Some  of you may also know how it is made. Mayonnaise is a liquid in liquid  dispersion, in fact a true  emulsion.  A true emulsion re

How different are the actions of antibodies against bacteria and against virus? Why is the cellular immune response activated in case of chronic viral infection? The antibodies

Monosaccharides :- Sugars consisting of  a  single  polyhydroxy  aldehyde or ketone unit.

Classic Procedure: The approach is the same as described earlier for open mitral valvotomy. The excision starts with an anterior incision on the anterior leaflet at 12o'clock p

Antiviral activity