Effects of bio-fertilizers on the production of specialized metabolites in Salvia officinalis L. leaves: An analytical approach based on LC-ESI/LTQ-Orbitrap/MS and multivariate data analysis.

In recent years, the use of organic substances has been increased to improve the production of specialized metabolites in aromatic and medicinal plants. Salvia officinalis L., known as sage, is an important medicinal and aromatic plant, whose leaves are commonly used as a condiment in food but mainly as a raw material in pharmaceutical and perfumery industries. In this work to define the effects of bio-fertilizers and foliar applications of l-phenylalanine on specialized metabolites production and biochemical characteristics of S. officinalis leaves, an experimental field in 2 years (2016 and 2017) was developed in semiarid climate, South-western, Iran. Experimental treatments included foliar spraying of l-phenylalanine in diverse concentration (0-250 and 500 mg/mL) and different bio-fertilizers [Arbuscular mycorrhizal fungi (AMF), Pseudomonas fluorescens (Pf), both fungi and bacteria (AMF + Pf)]. A metabolomics approach was carried out on the ethanolic extracts of sage leaves obtained by different treatments using Liquid Chromatography coupled with High-Resolution Mass Spectrometry (LC-ESI/LTQ-Orbitrap/MS) followed by multivariate data analysis. A total of 41 specialized metabolites were detected, and 35 of them were identified based on their accurate mass and mass fragmentation, as belonging to organic acids, phenylpropanoids, flavonoids, diterpenes, salvianolic acids and oxylipins. This work highlighted that the foliar application of l-phenylalanine along with the inoculation of Arbuscular mycorrhizal fungi and P. fluorescens can improve the yields of specific metabolites of pharmaceutical interest.