Adaptation of Glycyrrhiza glabra L. to water deficiency based on carbohydrate and fatty acid quantity and quality

Water deficit affects agricultural systems negatively globally. This research objective was to mitigate drought’s detrimental effects on plants metabolite profiling by utilizing biofertilizers and mineral nutrition. The carbohydrate content and fatty acid profile of Licorice (Glycyrrhiza glabra) were assessed under Silicon (Si) nutrition, Claroiedoglomus etunicatum inoculation (F), and drought stress (100, 80, 60, 40, and 20% of field capacity (FC)). Results showed that Si application increased total sugar content under severe drought levels (20 and 40% FC) and made it reach 12.41 and 12.63 g/100 g (DW), respectively. Sucrose, as the predominant sugar of licorice, was at its highest level (13.1 g/100 g (DW)) in response to integrated values of F and Si (60% FC). Gas chromatography–mass spectrometry showed that the majority of fatty acid components in plants were 9-Octadecenoic acid (8.72–71.27%), 9,12-Octadecadienoic acid (0.1–56.43%), Hexadecanoic acid (12.84–30.59%), Octadecanoic acid (6.9–15.3%), Docosanoic acid (0.57–2.77%), Eicosanoic acid (1.07–2.64%), and 7-Hexadecenoic acid (0.26–2.62%). Since a lower omega6/omega3 ratio represents a healthier product, the lowest ratio (0.25%) was observed in well-watered inoculated plants. Also, severe drought-treated plants under integrated Si and F applications showed a low omega6/omega3 ratio (1.88%). In conclusion, Si and F improved synergistically the carbohydrate content and fatty acid profile in plants, despite the drought stress.