Polyamines in plant stress response

Abstract

Polyamines (PAs) are ubiquitous biogenic amines that have been implicated in diverse cellular functions in all organisms. Recent work has demonstrated that mainly the three prominent PAs in plants, putrescine, spermidine, and spermine, have a role as part of the complex signaling networks activated in response to abiotic stresses and pathogen attack. In a network comprising the PAs itself, their catabolic products such as H 2 O 2 produced by action of diamine oxidases (DAO) and polyamine oxidases (PAO), and other compounds such as γ-aminobutyric acid (GABA), abscisic acid (ABA), and nitric oxide (NO), are part of interlaced cellular pathways. Current knowledge about PAs in plant stress responses is summarized in this chapter.