Polyamines: molecules with regulatory functions in plant abiotic stress tolerance

Abstract

Early studies on plant polyamine research pointed to their involvement in responses to different environmental stresses. During the last few years, genetic, transcriptomic and metabolomic approaches have unravelled key functions of different polyamines in the regulation of abiotic stress tolerance. Nevertheless, the precise molecular mechanism(s) by which polyamines control plant responses to stress stimuli are largely unknown. Recent studies indicate that polyamine signalling is involved in direct interactions with different metabolic routes and intricate hormonal cross-talks. Here we discuss the integration of polyamines with other metabolic pathways by focusing on molecular mechanisms of their action in abiotic stress tolerance. Recent advances in the cross talk between polyamines and abscisic acid are discussed and integrated with processes of reactive oxygen species (ROS) signalling, generation of nitric oxide, modulation of ion channel activities and Ca(2+) homeostasis, amongst others.

The effects of putrescine are partly overlapping with osmotic stress processes in wheat

“…Involvement of PAs in plant responses to environmental stimuli has been demonstrated by several studies. The protective effects of elevated endogenous level (either due to exogenous PA treatment or to transgenic modification) have been reported in several plant species under various stress conditions [1][2][3][4][5][6][7][8][9][10][11]. Besides their direct protective role PAs regulate fundamental cellular processes as signalling molecules, suggesting that abiotic stress tolerance is mainly influenced via signalling processes rather than by their accumulation [12].…”

Antioxidative responses of Salvinia (Salvinia natans Linn.) to aluminium stress and it’s modulation by polyamine

“…In plant system, polyamines (PAs) are a class of straight chain aliphatic compounds with different number of amino groups (di, tri and tetra), polycationic in nature are ubiquitously involved in growth and developmental processes (Alcazar et al 2010). Besides this, within physiological pH, polyamines owing to its polycationic nature and alkane backbone are readily offered in binding with negatively charged domains of cellular macromolecules like membrane lipids, nucleic acid, carboxy terminus of poly peptides, de-protonated phenolics, esters and others (Liu et al 2008).…”

Bacterial and Plant Signal Integration via D3-Type Cyclins Enhances Symptom Development in the Arabidopsis-Rhodococcus fasciansInteraction

“…Polyamines are aliphatic polycations whose structure allows the interaction with DNA, RNA, proteins, and phospholipids. Consequently, they are important regulators of growth and development (for recent reviews, see Alcázar et al, 2010;Takahashi and Kakehi, 2010). Besides the developmental modulation of polyamine levels, their concentration also increases when plants are challenged with abiotic or biotic agents, suggesting a protective role against environmental cues (Alcázar et al, 2010;Gill and Tuteja, 2010) and pathogens (Walters, 2003).…”

“…Put serves as a substrate for spermidine synthases (SPDS1 and SPDS2) to generate the polyamine spermidine (Spd), which is further modified by spermine synthase (SPMS) or by thermospermine synthase (ACL5) to yield spermine (Spm) or thermospermine (tSpm), respectively. Decarboxylated S-adenosyl-Met is the aminopropyl donor for the biosynthesis of these higher polyamines and is generated by S-adenosyl-Met decarboxylases (SAMDC1-SAMDC4) from S-adenosyl-Met (Alcázar et al, 2010;Mattoo et al, 2010). ADC and SAMDC activities are the rate-limiting steps in Put and Spd/Spm biosynthesis, respectively.…”

“…Generally, the steady-state levels of Spd and Spm are more tightly regulated than those of Put through transcriptional, translational, and posttranslational control mechanisms (for recent reviews, see Handa and Mattoo, 2010;Mattoo et al, 2010). However, the intracellular pool of free polyamines depends not only on the biosynthetic rate but also on several other processes, including transport, conjugation, and degradation (Persson, 2009;Alcázar et al, 2010;Angelini et al, 2010;.…”