title: Role of polyamines and ethylene as modulators of plant senescence.
abstract: Under optimal conditions of growth, senescence, a terminal phase of development, sets in after a certain physiological age. It is a dynamic and closely regulated developmental process which involves an array of changes at both physiological and biochemical levels including gene expression. A large number of biotic and abiotic factors accelerate the process. Convincing evidence suggests the involvement of polyamines (PAs) and ethylene in this process. Although the biosynthetic pathways of both PAs and ethylene are interrelated, S-adenosylmethionine (SAM) being a common precursor, their physiological functions are distinct and at times antagonistic, particularly during leaf and flower senescence and also during fruit ripening. This provides an effective means for regulation of their biosynthesis and also to understand the mechanism by which the balance between the two can be established for manipulating the senescence process. The present article deals with current advances in the knowledge of the interrelationship between ethylene and PAs during senescence which may open up new vistas of investigation for the future.
authors.affiliation: Plant Biotechnology Division, Institute of Himalayan Bioresource Technology, Palampur 176 061, India.
authors.forename: S
authors.initials: S
authors.lastname: Pandey
authors.forename: S A
authors.initials: SA
authors.lastname: Ranade
authors.forename: P K
authors.initials: PK
authors.lastname: Nagar
authors.forename: N
authors.initials: N
authors.lastname: Kumar
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000502:physiology; D001120:Arginine / Q000378:metabolism; D016922:Cellular Senescence; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D008715:Methionine / Q000378:metabolism; D008954:Models, Biological; D009955:Ornithine Decarboxylase / Q000502:physiology; D063245:Plant Development; D010937:Plant Growth Regulators / Q000502:physiology; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000502:physiology; D011073:Polyamines / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000502:physiology
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011073:Polyamines; D012436:S-Adenosylmethionine; C036216:ethylene; D001120:Arginine; D008715:Methionine; D009955:Ornithine Decarboxylase; D012437:Adenosylmethionine Decarboxylase