THE SENESCENCE SYNDROME IN PLANTS - AN OVERVIEW OF PHYTOGERONTOLOGY

The deteriorative processes leading to the death of a population, indi vidual or part of an individual can be genetically programmed or induc ed by environmental perturbations, physical damage, pests and diseases . Senescence in multicellular plants is typically a phenomenon resulti ng from cell differentiation and loss of totipotency. Recycling of nut rients released from senescent cells, abscission layer formation, cont ainment of pathogens and dispersal of progeny are crucial aspects of s enescence management. Senescence-related autocatalytic changes induced by substances generally thought to regulate senescence may not mirror the sequence of changes occurring naturally through correlative proce sses in the intact plant. The chloroplast has a key role in reversing senescence-related degradation of other organelles. Conventional sympt oms of senescence used in plant sciences have obscured common theories of senescence regulation for all types of organism.