Antimicrobial Drimane Sesquiterpenes Contribute to Balanced Antagonism but Do Not Structure Bacterial and Fungal Endophytes in the African Pepper Bark Tree Warburgia ugandensis

摘要: The African pepper bark tree, Warburgia ugandensis, accumulates antimicrobial drimane sesquiterpenes in all of its organs. One hypothesis states that plant defense compounds determine endophyte community structure. Another suggests they just facilitate the endophytic lifestyle by exerting a balanced antagonism. To explore this, representative selection bacterial and fungal isolates from this tree species was assayed together with six non-endophytic strains to their tolerance susceptibility root leaf extract fraction containing high low sesquiterpene amounts respectively. Inhibitory effects were explored assessing both growth efficiency, latter which relates respiratory activity growth. tested showed considerable variation obtained patterns did not allow clear distinction between endophytes as well non-endophytes. In addition, also against juglone, an redox-active aromatic naphthoquinone. A comparison differential pulse voltammograms efficacy variants deoxyribose degradation assay revealed possess anti- pro-oxidant activities compare those juglone. Leaf higher resistance oxidative stress than endophytes, quite contrary actual exposure. results support notion structural diverse can contribute antagonism but structuring communities. Oxidative seems be involved generating effect albeit it cannot explain alone.