Cytokinin and abscisic acid alleviate drought stress through changing organic acids profile, ion immolation, and fatty acid profile to improve yield of wheat (Triticum aestivum L .) cultivars

Abstract

There is an increasing interest for plant hormones to modulate the harmful effects of drought on crops. The present study was conducted to assess the effect of foliar-applied cytokin (CK) and abscisic acid (ABA) on yield, organic acids, minerals, and fatty acid profile of wheat (Triticum aestivum L.) cultivars (MV17 and Pishgam) in response to drought stress. The results showed drought significantly decreased grain yield and biomass, but they were enhanced by CK and ABA application. Acetic acid increased under drought stress conditions, and the remarkable increase (~ twofold) in succinic acid content was observed with ABA application under drought stress in MV17 cultivar. In general, drought stress decreased malic acid, pyruvic acid, and citric acid, but CK enhanced them. The leaf accumulations of potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe²⁺), and zinc (Zn²⁺) decreased by drought, where its reduction in MV17 was greater than Pishgam. However, an increased sodium (Na⁺) content was observed in plants experiencing drought with non-foliar application of ABA and CK. The plant growth hormones especially CK increased K⁺, Ca²⁺, Mg²⁺, Fe²⁺, and Zn²⁺, but decreased Na⁺. Fatty acid profile showed increased polyunsaturated fatty acids and monounsaturated fatty acids upon the drought stress. According to heat map, organic acids represented the maximum variations but fatty acids showed the minimum change during the treatments. The present study recommended foliar-applied CK to alleviate drought stress on wheat yield.

Keywords: Acetic acid; Irrigation regimes; Nutrients; Plant hormones; Polyunsaturated fatty acids.

Fig. 1

Grain yield and biomass of wheat cultivars treated with foliar-applied cytokinin (CK) and abscisic acid (ABA) at 20 µM under drought stress. Values are means ± standard deviation (SD) of three biological replicates. Different letters show statistically significant differences among treatments at P value ≤  0.05

Fig. 2

Heat map analysis for organic acids, fatty acids, and minerals in wheat cultivars treated with foliar-applied cytokinin (CK) and abscisic acid (ABA) under drought stress. T1: normal irrigation + MV17 + non-appplication of CK and ABA, T2: normal irrigation + MV17 + ABA, T3: normal irrigation + MV17 + CK, T4: normal irrigation + Pishgam + non-appplication of CK and ABA, T5: normal irrigation + Pishgam + ABA, T6: normal irrigation + Pishgam + CK, T7: drought + MV17 + non-appplication of CK and ABA, T8: drought + MV17 + ABA, T9: drought + MV17 + CK, T10: drought + Pishgam + non-appplication of CK and ABA, T11: drought + Pishgam + ABA, T12: drought + Pishgam + CK