Suppression of Phyllospheric Microbiota Alters Content of Pharmacologically Relevant Compounds of <i>S. nigra</i> Flowers

Accumulating scientific evidence suggests that medicinal plant-associated microbiota has a significant role in biosynthesis of pharmacologically relevant compounds. Suppression of S. nigra microbiota by an antibiotic treatment leads to a decreased emission of volatile terpenoids from S. nigra flowers and an altered metabolome of a host plant. However, it is not known if suppression of microbiota also affects an abundance of health promoting compounds and pharmacologically relevant properties of S. nigra. The present study reveals, that suppression of phyllospheric microbiota by an antibiotic treatment affects total phenolic content (TPC), anti-radical activity (ARA) and total flavonol content (Flav) of wild S. nigra flowers. Significance analysis of metabolites (SAM) performed using ultra high performance liquid chromatography-time of flight-masspectrometry (UHPLC-TOF-MS) based metabolomics data identifies pharmacologically relevant flavonols as metabolites discriminating between antibiotic treated and control flowers of S. nigra. Reported results substantiate need for a research investigating an effect of microbiota suppression on a biological activity of S. nigra flowers.