Polyamine Function in Plants: Metabolism, Regulation on Development, and Roles in Abiotic Stress Responses

Abstract

Polyamines (PAs) are low molecular weight aliphatic nitrogenous bases containing two or more amino groups. They are produced by organisms during metabolism and are present in almost all cells. Because they play important roles in diverse plant growth and developmental processes and in environmental stress responses, they are considered as a new kind of plant biostimulant. With the development of molecular biotechnology techniques, there is increasing evidence that PAs, whether applied exogenously or produced endogenously via genetic engineering, can positively affect plant growth, productivity, and stress tolerance. However, it is still not fully understood how PAs regulate plant growth and stress responses. In this review, we attempt to cover these information gaps and provide a comprehensive and critical assessment of the published literature on the relationships between PAs and plant flowering, embryo development, senescence, and responses to several (mainly abiotic) stresses. The aim of this review is to summarize how PAs improve plants' productivity, and to provide a basis for future research on the mechanism of action of PAs in plant growth and development. Future perspectives for PA research are also suggested.

Responses of young wheat plants to moderate heat stress

“…The interaction between PA metabolism and proline synthesis, SA signalling, or other stress-related processes has also been described (Pál et al 2015(Pál et al , 2018bSzalai et al 2017). Some PAOs catalyse the production of metabolic end-products of PAs, while some may catalyse the reverse reaction of PA synthesis in the PA cycle, the back-conversion of PAs (Pál et al 2015;Chen et al 2019). The conversion of PAs (PUT-SPD-SPM) is often described under stress conditions (Pál et al 2015).…”

“…The conversion of PAs (PUT-SPD-SPM) is often described under stress conditions (Pál et al 2015). To date, much less studies have focused on the molecular functions of PAs in plants under high temperature stress than under other stress conditions (Chen et al 2019). Exogenous SPD could improve carbohydrate and nitrogen status of tomato seedlings at high temperatures through regulating the gene expression and activity of key enzymes for nitrogen metabolism (Shan et al 2016).…”

Short-Term Temporal Metabolic Behavior in Halophilic Cyanobacterium Synechococcus sp. Strain PCC 7002 after Salt Shock

“…Polyamines are polycationic aliphatic amines found in all living organisms and affect DNA folding, protein synthesis, membrane stability, photosystem II stability, and stress responses, although the underlying mechanisms are not completely understood [41]. Intracellular polyamine level increases because of salt stress in both halophytes and glycophytes [42,43]. Some polyamines, including putrescine, spermine, and spermidine, are found in cyanobacteria.…”

The plasma‐membrane polyamine transporter PUT3 is regulated by the Na+/H+ antiporter SOS1 and protein kinase SOS2

“…In plants, PAs have also been implicated in growth, development and stress responses (Chen et al ., ). The role of PAs in abiotic stress tolerance is supported by the fact that the biosynthesis of PAs is enhanced under different stress conditions, and exogenously applied PAs elevate plant stress tolerance (Liu et al ., ).…”