Arbuscular mycorrhizal fungi affect total phenolic content and antimicrobial activity of Tamarix gallica in natural semi-arid Algerian areas

Abstract Polyphenolic compounds gained interest in the pharmaceutical research due to their beneficial bioactive compound for a healthy diet. Arbuscular mycorrhizal fungi (AMF) are known to interact with host plant metabolism, inducing accumulation of health-promoting phytochemicals and polyphenolic molecules. Tamarix gallica is a halophytic species having hepatotonic and stimulant properties. Leaf, flower and root infusion have anti-inflammatory and anti-diarrheic properties. The purpose of this study was to assess the presence and the diversity of arbuscular mycorrhizal fungi associated with T. gallica rhizosphere in Algerian steppic semi-arid site and to evaluate antimicrobial activities of leaf and root phenolic extracts. Four glomoid and one gigasporoid AMF spores type were isolated from rhizosphere of mycorrhizal Tamarix specimens. Total phenolic compounds were higher in roots than in leaves. Furthermore, T. gallica extracts showed significant antimicrobial properties against human pathogen bacterial strains. The mean inhibition zone was from 0 to 15 mm when concentration increased from 1 to 100 mg l −1 . The highest significant activity for leave and root methanolic extracts was observed against Proteus mirabilis . Positive correlation was recorded between AMF root colonization and antimicrobial activity. Significant effect of plant type, soil characteristics and AMF root colonization on polyphenolic content was noticed. These findings highlight the complexity of T. gallica /AMF symbiosis and their effect on polyphenolic compounds and suggest that T. gallica inoculated with arbuscular mycorrhizal fungi may be considered as an interesting source of antioxidants for therapeutic or nutraceutical industries and for food manufactures.