senescence

Examples of senescence in the following topics:

• Plant Life Spans

  • The aging of a plant and all the associated processes is known as senescence, which is marked by several complex biochemical changes.
  • One of the characteristics of senescence is the breakdown of chloroplasts, which is characterized by the yellowing of leaves .
  • Hormones are known to play a role in senescence.
  • Applications of cytokinins and ethylene delay or prevent senescence; in contrast, abscissic acid causes premature onset of senescence.
  • The autumn color of these Oregon Grape leaves is an example of programmed plant senescence.

• Auxins, Cytokinins, and Gibberellins

  • Cytokinins are known to delay senescence in leaf tissues, promote mitosis, and stimulate differentiation of the meristem in shoots and roots.
  • Other effects of GAs include gender expression, seedless fruit development, and the delay of senescence in leaves and fruit.

• Muscle Development

  • Human embryonic stem cells are pluripotent; that is, they can differentiate into any of the cell types present in the adult human, and into any of the intermediate progenitor cell types that eventually turn into the adult cell lines. hESCs are also immortal: they can divide and grow in number indefinitely, without undergoing either differentiation or cellular aging (cellular senescence).

• Caulobacter Differentiation

  • Reproductive senescence was measured as the decline in the number of progeny produced over time.

• Abscisic Acid, Ethylene, and Nontraditional Hormones

  • Aging tissues (especially senescing leaves) and nodes of stems produce ethylene.