Endophytic Aureobasidium pullulans BSS6 assisted developments in phytoremediation potentials of Cucumis sativus under Cd and Pb stress

In the current study, we aimed to elucidate the bioremediating potential of endophytic fungi during various heavy metals stresses to the cucumber (Cucumis sativus) plants. Preliminary screening showed that endophyte (Aureobasidium. pullulans BSS6) produced IAA and extra-cellular enzymes (phosphatase, cellulase and glucosidase). Therefore, BSS6 was inoculated to cucumber plants during short term (24 h) heavy metals stress (STM) and long-term (7 days) heavy metals stress (LTM). Results showed that antioxidant activities (catalase, peroxidase and reduced glutathione) were significantly enhanced and lipid peroxidation inhibited during stress conditions in A. pullulans BSS6 inoculated plants, particularly in LTM stress. The ameliorative effects of BSS6 were evident from the quantification of results and were found to significantly regulate soil enzymatic activities: including (beta -glucosidase, phosphatases and cellulases) during STM and LTM. Hence, endophytic BSS6 proved to be efficient in improving cucumber tolerance during metal contamination via regulating soil enzymatic activities to reduce metal uptake and boost the antioxidant system.