Allelopathic inhibition effects and mechanism of phenolic acids to Microcystis aeruginosa

Effects of Lagarosiphon major extracts on the metabolome and photosynthesis of Microcystis aeruginosa

“…In particular, we report that L. major extract inhibits M. aeruginosa photosynthesis, with a clear drop in the cyanobacteria photosynthetic yield at a concentration of 10 g•l −1 . Photosynthesis is a key physiological process targeted by allelopathic compounds [16,44]. Numerous studies suggest that allelochemicals from macrophytes show photosynthesis inhibitory properties by disrupting the electron transport chain, reducing pigment content, or modifying Chl a fluorescence [45].…”

“…Among putative annotated metabolites, the following may be involved in allelopathic interactions between macrophytes and cyanobacteria as recently reviewed by Zhu et al [12] and Mohamed [7]: the phenylpropanoids p-coumarate, caffeic acid; the polyphenols vanillic acid and salicylic acid glucoside, luteolin 7-O-beta-D-diglucuronide; the flavonoid quercetin 3-galactoside; the triterpenoids saponines spinasaponin A, acutoside A, lucyoside M and saikosaponina A; the fatty acids 3-hydroxyoctanoic acid, coronaric acid, pinellic acid, conelenic acid and octyl docosanoate. Among them, caffeic acid has been recently described as highly active in the mg•l −1 range concentration on M. aeruginosa, leading to growth impairment, reactive oxygen species (ROS) production and modulation of various metabolic pathways [16,61].…”

“…In this context, allelopathically active compounds from aquatic vascular plants may offer an interesting option for effective biocontrol of cyanobacteria growth. For instance, different physiological and biochemical processes in cyanobacteria are affected by macrophyte extracts [15,16]: disturbance of the membrane integrity, oxidative stress, inhibition of extracellular enzyme activity, inhibition of photosynthesis, and respiration.…”

“…Despite their relevance, these methods show limitations in terms of precocity and precision of the response measured to different concentrations of bioactive molecules [27]. To tackle this issue, it appears in recent literature that metabolomic approaches may show a higher sensitivity in identifying allelopathic interactions, particularly between cyanobacteria and macrophytes [16,28]. Metabolomics make it possible to investigate tenuous and early molecular responses as they precede changes in metabolism and growth [29].…”

“…Different techniques are used to implement metabolomic analyses such as nuclear magnetic spectrometry (NMR) or highresolution mass spectrometry (HRMS) coupled with separation techniques such as liquid chromatography (LC) or gas chromatography (GC). Regarding, allelopathic interactions in aquatic ecosystems, the untargeted approach based on LC-HRMS/MS is currently the most widespread method since it both allows to determine the molecular/biochemical response to the stress and to identify the secondary metabolites (bioactive compounds) potentially involved [16,34]. To this end, such a method is often combined with bioguided fractionation in order to direct the identification toward the active metabolites [35].…”