Jasmonic and Abscisic Acid Contribute to Metabolism Re-adjustment in Strawberry Leaves under NaCl Stress

Abstract

ABSTRACT The aim of this research was to evaluate the effect of exogenous jasmonic acid and abscisic acid, at different salinity regimes, on primary and secondary metabolic changes in ʻKurdistanʼ and ʻQueen Elisaʼ strawberry leaves. To this end, strawberry plants were induced by gradual NaCl salinity (10 mmol•L−1) and shock salinity. The plants were sprayed with ABA (40 mmol•L−1) and JA treatments up to 40 mmol•L−1. In both cultivars, salt shock stress significantly enhanced the total antioxidant capacity, though the JA treatment outperformed the ABA treatment. Increasing JA level in the presence of ABA resulted in downswing in total phenolic content (6.42% in ʻKurdistanʼ and 23.13% in ʻQueen Elisaʼ) and antioxidant capacity (12.9% in ʻKurdistanʼ and 17.7% in ʻQueen Elisaʼ) at non-saline conditions. Adding both hormonesresulted in a 20.82% increase in total phenolic content and a 17.86% increase in total antioxidant capacity in ‘Kurdistan’ at gradual salt stress; however, in ʻQueen Elisaʼ, the same treatment resulted in 21.98% increase in total phenol and 11.92% increase in total antioxidant capacity at salt shock. Salt shock induced tyrosine increase and both hormones enhanced asparagine, alanine, histidine, and GABA contents in ʻQueen Elisaʼ. The study reveals that the applation of abscisic acid along with different jasmonic acid concentrations activates the protective mechanism of the strawberry plant against NaCl stress. Further studies are needed to compare the exact salt stress tolerance mechanisms for these cultivars. Abbreviations: JA: Jasmonic acid; ABA: Abscisic Acid; GABA: γ-Aminobutyric acid