Molecular Genetics of Flower Senescence

Senescence is the terminal phase in the development of a plant, plant organ or plant tissue. Flower senescence, for example, occurs after pollination when the petals no longer serve a useful purpose, and for certain flowers is accompanied by a climacteric rise in ethylene production. In carnation, this climacteric surge in ethylene formation is temporally coincident with inrolling of the petals, which is the first morphological manifestation of petal senescence (Thompson et al.,1982). Petal inrolling is thought to reflect loss of cell turgor attributable to membrane leakiness. Indeed, there is growing evidence that a progressive decline in membrane selective permeability and the ensuing loss of intracellular compartmentation are characteristic features of both flower and leaf senescence (Thompson et al., 1998).