Plant senescence

Leaf senescence has the important function of recycling nutrients, mostly nitrogen, to growing and storage organs of the plant.

[3] A withdrawal of or inability of the cell to perceive cytokinin may cause it to undergo apoptosis or senescence.

[2] The theory holds that leaves and roots are routinely pruned off during the growing season whether they are annual or perennial.

This is done mainly to mature leaves and roots and is for one of two reasons; either both the leaves and roots that are pruned are no longer efficient enough nutrient acquisition-wise or that energy and resources are needed in another part of the plant because that part of the plant is faltering in its resource acquisition.

This is an oversimplification, in that it is arguable that some shoot and root cells serve other functions than to acquire nutrients.

There is little theory on how plants induce themselves to senesce, although it is reasonably widely accepted that some of it is done hormonally.

[6] In dry, aging rye seeds, DNA damages occur with loss of viability of embryos.