Interaction of polyamines, abscisic acid and proline under osmotic stress in the leaves of wheat plants

Abstract

The exact relationship between polyamine, abscisic acid and proline metabolisms is still poorly understood. In the present study, the effects of putrescine and abscisic acid treatments alone or in combination with polyethylene glycol-induced osmotic stress were investigated in young wheat plants. It was observed that abscisic acid plays a role in the coordinated regulation of the proline and polyamine biosynthetic pathways, which compounds are related to each other through a common precursor. Abscisic acid pre-treatment induced similar alteration of polyamine contents as the osmotic stress, namely increased the putrescine, but decreased the spermidine contents in the leaves. These changes were mainly related to the polyamine cycle, as both the synthesis and peroxisomal oxidation of polyamines have been induced at gene expression level. Although abscisic acid and osmotic stress influenced the proline metabolism differently, the highest proline accumulation was observed in the case of abscisic acid treatments. The proline metabolism was partly regulated independently and not in an antagonistic manner from polyamine synthesis. Results suggest that the connection, which exists between polyamine metabolism and abscisic acid signalling leads to the controlled regulation and maintenance of polyamine and proline levels under osmotic stress conditions in wheat seedlings.

Coordinated mechanisms of leaves and roots in response to drought stress underlying full-length transcriptome profiling in Vicia sativa L

“…Compared with the "plant hormone signal transduction" and "starch and sucrose metabolism" pathways, "arginine and proline metabolism" is the third most important pathway enriched in common vetch leaves and roots. Some recent findings also showed that arginine, proline, and amines could regulate cellular osmotic adjustment, stabilize proteins and enzymes, and prevent cell membrane injury during water-limited conditions, indicating a positive association between amino acid metabolism, accumulation and turnover in drought tolerance in plants [18,[63][64][65]. In tobacco, the expression of three PDH genes (the key enzyme in proline degradation) was persistently inhibited both in leaves and roots from weak (1-day) to strong (6-d) dehydration conditions, resulting in 5-10 times higher proline concentrations in plants under dehydration conditions than the plants under control conditions [66].…”

Molecular background of cadmium tolerance in Rht dwarf wheat mutant is related to a metabolic shift from proline and polyamine to phytochelatin synthesis

“…In addition, higher ABA content may increase the expression level of the genes involved in PA metabolism (Alcázar et al 2006). Similarly, ABA application and accumulation resulted in proline accumulation and increased gene expression of P5CS1, OAT and PAO in wheat (Pál et al 2018b). Our data indicated that there is no direct correlation between changes in PCs and SA or ABA contents in the roots.…”

“…For example, recently, it was found that 1-day ABA treatment induced the gene expression of both enzymes, but 1-day PUT treatment only the P5CS1, while osmotic stress after 5 days did not induced any changes in the transcript level either of these gene, despite the fact that proline accumulation occurred. In addition, it was also revealed that the synthesis pathway of PA and proline is regulated partly independently, despite the common precursor, glutamate (Pál et al 2018b). Furthermore, it should be also taken into consideration that not only the syntheses of PA and proline are linked but also the PA catabolism has also been shown to be closely related to proline accumulation (Aziz et al 1998).…”

Responses of young wheat plants to moderate heat stress

“…Recent findings suggest that they are not only direct protective materials, but also function as signal triggering certain acclimation mechanisms. 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).…”