Aspetti cellulari, fisiologici e molecolari della senescenza nelle piante

Senescence is the final stage of development of an organ; in a leaf, this syndrome is characterized by a gradual yellowing, loss of protein content and change in the metabolism, which eventually lead to death. It is generally a slow degenerative process during which nutrients are mobilized and translocated to other parts of the plant. Senescence is under control of environmental and endogenous factors. In general, cytokinins produce a delay in leaf senescence and their levels have been observed to decline in senescing leaf tissues. In contrast, ethylene and abscissic acid can accelerate the onset of senescence. The study of plant senescence may help to clarify numerous general aspects of organ development and contribute to better understanding programmed cell death. Herein, we specifically explore senescence and its regulation.