Phenolic Compounds as Biomarkers of Interactions between the Endophyte Klebsiella oxytoca and the Common Duckweed, Lemna minor L.

Abstract

The common duckweed (Lemna minor L.) as a model organism is experiencing a form of a renaissance. In this study, our focus was on the interactions between duckweeds and a rhizosphere-associated bacterial strain, Klebsiella oxytoca (Access. No. MK212915). Five distinct phenolic compounds were identified by liquid chromatography–mass spectrometry: luteolin 6,8-di-C-hexoside, p-hydroxybenzoic acid, caffeic acid, apigenin 6-C-(2′′-pentosyl)hexoside and p-coumaric acid. All of the identified compounds reflect the colonization of the plant by K. oxytoca. This paper is another call for all plant physiologists to focus their research on L. minor and to analyze different aspects of complex plant/bacterium interactions.