Senescence - Effects of Plant Growth Regulators on Development

All five major growth regulator groups: auxins, gibberellins cytokinins, abscisic acid and ethylene can influence senescence in a wide range of species and this may indicate that all these compounds participate in natural senescence. In many organisms ageing and loss of viability occur as a result of accumulated metabolic errors and cell damage. On the other hand, senescence of leaves and homologous organs (cotyledons, petals, etc.) is believed to be a programmed process. In the following subsections we will discuss various aspects of senescence.