Plant senescence is the study of aging in plants.

It was concluded that the At2-MMP has a physiological role in mature aging tissue and the possibility of being involved in plant senescence.

Cladoptosis is thought to have three possible functions, self-pruning (i.e. programmed plant senescence), drought response (characteristic of xerophytes) and liana defence.

When leaves degreen in the process of plant senescence, chlorophyll is converted to a group of colourless tetrapyrroles known as nonfluorescent chlorophyll catabolites (NCC's) with the general structure: