Abscisic acid signals reorientation of polyamine metabolism to orchestrate stress responses via the polyamine exodus pathway in grapevine

ABA-dependent amine oxidases-derived H2O2 affects stomata conductance

“…16 reported that ABA is inducing AtPAOs in Arabidopsis, enhancing the back-conversion pathway of PAs in peroxisomes. Although the peroxisomal pathway is functionally divergent from the apoplastic PA catabolic pathway described by Moschou et al 1 and Toumi et al 11 both pathways are induced by ABA (Fig. 2).…”

“…The perceived signal involves the ABA signaling pathway. 11 With respect to the PA catabolic pathway, Moschou et al 1 and Toumi et al 11 showed that stress induces exodus of PAs into the apoplast, were they are catabolized by PAO. Grape cultivars showing contrasting tolerance to drought stress exhibit differential PA biosynthesis rate and titers.…”

“…1,7 Now we have shown that PA exodus also occurs in Vitis vinifera and this phenomenon is at least partially induced by abscissic acid (ABA). 11 Thus, exogenous microscopy (SEM) showed that in Spdtreated leaf epidermis, Spd induced stomata closure (Fig. 1D), which was restricted by simultaneous application of aminoguanidine and guazatine (Fig.…”

Exogenous putrescine increases the responsiveness of thermodormant Avena fatua L. caryopses to karrikinolide and gibberellic acid

“…There are several reports proving the connection between ABA signaling, polyamines metabolism and plant defense system (Toumi et al 2010;Marco et al 2011;Saha et al 2015). Therefore, we attempted to elucidate a probable connection between exogenous Put effects and endogenous ABA in thermodormancy induction and alleviation in A. fatua caryopses.…”

Response, Tolerance and Adaptation to Abiotic Stress of Olive, Grapevine and Chestnut in the Mediterranean Region: Role of Abscisic Acid, Nitric Oxide and MicroRNAs

“…Effectively, Cramer (2010) has recently emphasized that many of the grapevine responses to osmotic stress appear to be transcriptionally regulated, but proteomic studies indicate that there are post-translational controls as well. Also, metabolite profiling has revealed that accumulation of amino acids and polyamines (PAs) is dependent on ABA production, suggesting the integration of ABA signaling to accumulation of protective molecules (Toumi et al, 2010). The ABA signaling pathway integrates PAs and amine oxidases (AOs) in order to regulate the generation of hydrogen peroxide (H 2 O 2 ), which signals further stress responses of the programmed cell death (PCD) syndrome.…”