Exogenous application of abscisic acid to root systems of grapevines with or without salinity influences water relations and ion allocation

Abstract

Background and Aims: Exposure to salinity or water deficit is known to increase the concentration of abscisic acid (ABA) within grapevines. Elevated plant ABA has alone been shown to reduce the flux of chloride from roots to shoots. The aim was to evaluate the effect of exogenously applied ABA to grapevine root systems, with or without saline irrigation water, on water relations and ion allocation. Methods and Results: Vitis vinifera (Shiraz, clone EVOVS12) vines on own roots were treated with a control of nutrient solution only, and with other treatments, also in nutrient solution, consisting of 75 mmol/L chloride (Cl À ) salts [cations: 45 mmol/L sodium (Na + ), 7.5 mmol/L calcium (Ca ++ ), 7.5 mmol/L magnesium (Mg ++ )], 50 and 100 μmol/L ABA, and 75 mmol/L Cl À salts plus 50 and 100 μmol/L ABA, all applied by watering to roots of potted vines in a glasshouse. Treatments were applied for 14 days before the plants were destructively harvested for ion analysis. All applied treatments reduced stomatal conductance, assimilation and transpiration, but ABA plus Cl À salts did not result in further reduction compared with that of ABA alone. Abscisic acid, only in the presence of salt, reduced Cl À concentration in all vine structures except the roots, while the concentration of Na + , K + and Ca ++ was less affected. This reduction could not be accounted for by reduced transpiration. Conclusion: In the presence of excess Cl À salts, ABA applied exogenously to Shiraz roots reduced Cl À transport to the shoot. Significance of Study: This provides some insight into the ability of deficit irrigation techniques to modify water relations and ion concentration.

Grapevine salt tolerance

“…Furthermore, in salt-stressed Sultana grapevines, lower Cl − accumulation and stomatal closure has been observed in leaves treated with exogenous ABA (Downton et al 1990). This was also seen in the cultivar Shiraz/Syrah when ABA was directly applied to roots (Degaris et al 2017). Ayadi et al (2020) reported the expression of the gene VviNHX6, as tested on in vitro cultivated cells from Cabernet Sauvignon grapes, to be higher when salicylic acid or ABA is applied, compared to salinity, therefore these hormonal treatments might be taken into consideration to investigate possible ways to anticipate or enhance a response to salinity.…”

Coastal Wild Grapevine Accession (Vitis vinifera L. ssp. sylvestris) Shows Distinct Late and Early Transcriptome Changes under Salt Stress in Comparison to Commercial Rootstock Richter 110

“…Pyricularia Oryzae Resistance 21 is a glycoprotein reported to be able to decrease salicylic acid activity, while promoting jasmonic acid and ABA during pathogen defensive responses in rice [ 133 ]; however it is unclear whether the grapevine homolog here shares similar functions. Despite the hormone response in both varieties sharing similarities in terms of salicylic acid and ABA signaling, which is known to promote salt tolerance in grapevine [ 134 ], the signaling processes from AS1B could be more inclined toward ion transport through the calcium-mediated pathways, while R110 seems to maintain a more diverse regulatory activity (with a larger amount of DEGs) but is less specific toward salt stress, with responses against biotic stresses aside from salt stress.…”

Grapevine abiotic stress assessment and search for sustainable adaptation strategies in Mediterranean-like climates. A review

“…In grapevines, many studies regarding the preharvest application of several treatments demonstrated benefits in managing plant stress responses and improving stress tolerance (Table 1). For instance, a number of authors demonstrated that exogenous applications of ABA, auxins, salicylic acid, gibberellin and kinetin, enhanced yield and graft union formation, increased total phenols, and promoted changes in berry sugar, acidity, and color (Köse and Güleryüz 2006;Deytieux-Belleau et al 2007;Zhang 2011;Blazquez et al 2014;Abdel-Salam 2016b;Degaris et al 2017;El-kenawy 2017). Moreover, Meng et al (2018) reported that melatonin pre-harvest application could benefit phenolic content and antioxidant activity in the "Merlot" variety (Meng et al 2018).…”