Physiology of Senescence and Ageing, programmed cell death
.bmp)
Physiology of Senescence and Ageing :- The condition or process of deterioration with age is called senescence. It is a process by which a cell ages and permanently stops dividing but does not die. It is found naturally in desiduous plants. Gibberellin hormone reduces senescence in plants while ABA hormone increases senescence in plants. Causes of senescence:- > Process of leaf senescence comes along with early loss of chlorophyll, enzymes and RNA. > As a result of a faster break down or slower synthesis, there is a decrease in the cellular constituents. > Competition between reproductive and vegetative structures for nutrients. > Long-night and short-day conditions induce leaf senescence and flowering. > Senescence factor is secreted in fruits of soybean which passes to leaves causing senescence. > The process of senescence is also governed hormonally. > Loss of integrity in food storage cells of seeds and degradation of food reserves. Physiological changes o...