Polyamines in plants: biosynthesis from arginine, and metabolic, physiological, and stress-response roles

Authors: Mattoo, Autar; FATIMA, TAHIRA - University Of Western Ontario; UPADHYAY, RAKESH - Pennsylvania State University; HANDA, AVTAR - Purdue University

Submitted to: CAB International United Kingdom
Publication Type: Book / Chapter
Publication Acceptance Date: 11/7/2014
Publication Date: 4/2/2015
Citation: Mattoo, A.K., Fatima, T., Upadhyay, R.K., Handa, A.K. 2015. Polyamines in plants: biosynthesis from arginine, and metabolic, physiological, and stress-response roles. In: D'Mello, F., editor. Amino Acids in Higher Plants. Boston, MA: CAB International United Kingdom. 10:171-194.

Interpretive Summary: Polyamines are a class of biogenic amines that are ubiquitous in living cells and have been found to have a wider influence on plant growth and development. Of particular significance is the recently determined link between polyamine concentrations and the ability of plants to withstand various abiotic stressors including drought, salinity, mineral deficiency and heat. The elucidation of the fundamental mechanism(s) for polyamine functioning is paramount to understanding what cues plants use to increase or decrease the machinery that results in the accumulation of different polyamines in plants. The levels of major polyamines, putrescine, spermidine and spermine, vary considerably in each plant organ during growth and development. Previously, we showed that each polyamine has a unique influence on the pattern of gene transcripts and accumulation of cellular nutrients. Interest in research on polyamines has recently surged based on new research implicating polyamines as plant growth regulators. It is not, however, known what mechanisms regulate biosynthesis of polyamines, and what signaling cascade is the determining factor. In this invited book chapter, we have collated and critically reviewed information on the biosynthesis of polyamines from arginine and role of polyamines in metabolism, physiology and stress tolerance in plants. This chapter fills a void in providing one-stop summarized information on the recent vast literature on the subject matter and will be of interest to scientists and physiologists alike.

Technical Abstract: Biogenic amines in all organisms including plants affect a myriad of growth and developmental processes. Therefore, there is continued interest in understanding their (here polyamines) biosynthesis and functional roles in regulating plant metabolism, physiology and development. The role of polyamines in plant responses to environmental stresses has also elicited considerable interest in recent years. Four major biogenic amines and their derivatives commonly found in plants are putrescine (Put), spermidine (Spd), spermine (Spm) and thermospermine (T-Spm). Biosynthesis of these polyamines derives from arginine (Arg) and/or ornithine (Orn). This chapter’s focus is on the Arg pathway. Genes encoding enzymes in the various steps of polyamine biosynthesis from Arg have been identified and characterized from a number of plants. The enzymes catalyzing different steps in the Arg pathway are: Arg decarboxylase, agmatine iminohydrolase/agmatine deiminase, N-carbamoylputrescine amidase/N-carbamoyl Put amido hydrolase, adenosylmethionine decarboxylase, Spd synthase, Spm synthase, thermospermine (T-Spm) synthase. Many of these have been purified and studied using heterologous expression systems. Advanced genetics tools and mutants have been used including production of loss-of-function and gain-of-function plants. The studies thus far have provided unequivocal evidence of polyamine roles in diverse aspects of plant life. Characterizations of isogenic mutants varying in endogenous levels of different polyamines have revealed that polyamines are central to important signaling and metabolic pathways and affect grain filling, senescence, nodulation, root development, and fruit ripening, as well as having a role in abiotic stress responses of plants.