Polyamines function in stress tolerance: from synthesis to regulation

Abstract

Plants are challenged by a variety of biotic or abiotic stresses, which can affect their growth and development, productivity, and geographic distribution. In order to survive adverse environmental conditions, plants have evolved various adaptive strategies, among which is the accumulation of metabolites that play protective roles. A well-established example of the metabolites that are involved in stress responses, or stress tolerance, is the low-molecular-weight aliphatic polyamines, including putrescine, spermidine, and spermine. The critical role of polyamines in stress tolerance is suggested by several lines of evidence: firstly, the transcript levels of polyamine biosynthetic genes, as well as the activities of the corresponding enzymes, are induced by stresses; secondly, elevation of endogenous polyamine levels by exogenous supply of polyamines, or overexpression of polyamine biosynthetic genes, results in enhanced stress tolerance; and thirdly, a reduction of endogenous polyamines is accompanied by compromised stress tolerance. A number of studies have demonstrated that polyamines function in stress tolerance largely by modulating the homeostasis of reactive oxygen species (ROS) due to their direct, or indirect, roles in regulating antioxidant systems or suppressing ROS production. The transcriptional regulation of polyamine synthesis by transcription factors is also reviewed here. Meanwhile, future perspectives on polyamine research are also suggested.

Syringaldazine peroxidase stimulates lignification by enhancing polyamine catabolism in wheat during heat and drought stress

“…The activities of the polyamine metabolising enzymes, are induced by stresses, resulting in enhanced stress tolerance. A number of studies have demonstrated that polyamines function in stress tolerance largely by modulating the homeostasis of reactive oxygen species (ROS) due to their direct, or indirect, roles in regulating antioxidant systems or suppressing ROS production (Liu et al 2015).…”

A cold responsive ethylene responsive factor from Medicago falcata confers cold tolerance by up-regulation of polyamine turnover, antioxidant protection, and proline accumulation

“…Polyamines regulate plant growth, development, and responses to environmental stresses (Liu, Wang, Wu, Gong, & Moriguchi, ). Putrescine (Put), spermidine (Spd), and spermine (Spm) are three major polyamines in plants.…”

Gamma-Glutamylpolyamine Synthetase GlnA3 Is Involved in the First Step of Polyamine Degradation Pathway in Streptomyces coelicolor M145

“…They were also reported to be involved in environmental stress response (Valdes-Santiago and Ruiz-Herrera, 2013; Alcazar and Tiburcio, 2014; Minocha et al, 2014; Liu et al, 2015; Pal et al, 2015), defense response (Walters, 2003; Wimalasekera et al, 2011; Zeier, 2013; Hatmi et al, 2014; Mo et al, 2015; Rossi et al, 2015) and apoptosis (Moschou and Roubelakis-Angelakis, 2014; Parhamifar et al, 2014; Cai et al, 2015). Polyamines are positively charged molecules able to interact with negatively charged molecules like RNA, DNA, proteins, polyphosphate, and phospholipids (Norris et al, 2015).…”