Diversity and bioactivities of fungal endophytes from Distylium chinense, a rare waterlogging tolerant plant endemic to the Three Gorges Reservoir

Abstract

BackgroundThe present study involves diversity and biological activities of the endophytic fungal community from Distylium chinense, a rare waterlogging tolerant plant endemic to the Three Gorges Reservoir. This study has been conducted hypothesizing that the microbial communities in the TGR area would contribute to the host plant tolerating a range of abiotic stress such as summer flooding, infertility, drought, salinity and soil erosion etc., and they may produce new metabolites, which may possess plentiful bioactive property, especially antioxidant activity. Therefore in the current study, the antioxidant, antimicrobial and anticancer activities of 154 endophytes recovered from D. chinense have been investigated. Furthermore, the active metabolites of the most broad-spectrum bioactive strain have also been studied.ResultsA total of 154 fungal endophytes were isolated from roots and stems. They were categorized into 30 morphotypes based on cultural characteristics and were affiliated with 27 different taxa. Among these, the most abundant fungal orders included Diaporthales (34.4%) and Botryosphaeriales (30.5%), which were predominantly represented by the species Phomopsis sp. (24.7%) and Neofusicoccum parvum (23.4%). Fermentation extracts were evaluated, screening for antioxidant, antimicrobial and anticancer activities. Among the 154 isolates tested, 99 (64.3%) displayed significant antioxidant activity, 153 (99.4%) exhibited inclusive antimicrobial activity against at least one tested microorganism and 27 (17.5%) showed exclusive anticancer activity against one or more cancer cell lines. Specifically, the crude extract of Irpex lacteus DR10–1 exhibited note-worthy bioactivities. Further chemical investigation on DR10–1 strain resulted in the isolation and identification of two known bioactive metabolites, indole-3-carboxylic acid (1) and indole-3-carboxaldehyde (2), indicating their potential roles in plant growth promotion and human medicinal value.ConclusionThese results indicated that diverse endophytic fungal population inhabits D. chinense. One of the fungal isolate DR10–1 (Irpex lacteus) exhibited significant antioxidant, antimicrobial and anticancer potential. Further, its active secondary metabolites 1 and 2 also showed antioxidant, antimicrobial and anticancer potential.

Insights into the Bioprospecting of the Endophytic Fungi of the Medicinal Plant Palicourea rigida Kunth (Rubiaceae): Detailed Biological Activities

“…Fungi of the order Botryosphaeriales have also been reported in the global literature as endophytic, living in plant tissues for long periods. However, other species of the order are phytopathogens and some cause opportunistic infections in humans [ 74 , 75 , 76 ] isolated 52 endophytes of the order Botryosphaeriales from Distylium chinense , which showed significant antioxidant activity and antimicrobial activity against at least one of the microorganisms evaluated by the authors. Diaporthe sp., isolated from the leaves of the medicinal plants Vernonia polyanthes and Anacardium othonianum from the savanna, demonstrated antimicrobial activity against Leishmania amazonensis [ 77 ] and were able to solubilize phosphate [ 78 ].…”

Marine endophytic fungal metabolites: A whole new world of pharmaceutical therapy exploration

“…The effect of seasons, locations and plant species on the variety of fungal endophyte and secondary metabolites produced from endophytic strains were discussed [ 47 , 48 ]. For example, analysis of fungal endophyte obtained from the same plant, Terminalia sp.…”

“…Since the number of marine organisms is so large, it is important to devise creative and imaginative strategies that provide superior prospects for isolating new endophytic fungi as well as emergence of new and diverse biologically active compounds with pharmaceutical applications [ 30 ]. These strategies include; 1) searching about unique fungal sources as the deep-sea, hydrothermal vents, hyper saline water bodies and hypoxic environments, offshore waters, and oil polluted regions which are prospective to be a host for endophytes with unusual bioactive products are recommended in upcoming years [ 31 ], 2) the culture-independent molecular technique and meta-genomic method aim to reveal microbial variety, particularly real symbioses that can be gained through vertical transmission among generations [ 47 ], 3) the progress of new isolation method copying the natural environments to obtained new symbiosis particularly uncultured symbiotic fungi and great-flux screening procedure for assaying the biological activity [ 4 , 6 , 23 ], 4) successful isolation approach for trace natural compounds and great-flux selection procedure for assaying the biological activity [ 56 ], 5) selection about gene cluster participates in the biosynthesis of significant pharmaceutical and medical metabolites and detection of biosynthesis mechanisms [ 1 , 2 , 27 ], and 6) heterologous expression of pharmacological metabolites of uncultured symbiosis and huge scale productivity of natural compounds [ 3 , 41 ].…”

Current Insight into Culture-Dependent and Culture-Independent Methods in Discovering Ascomycetous Taxa

“…Certain endophytic fungi may require growing conditions hitherto unknown. Moreover, with culture-dependent techniques, there is a likelihood of fast-growing fungal isolates inhibiting/masking slow-growing isolates on isolation media, often rendering them invisible [165,166]. The final endophyte community assembly of a host plant is a delicate balance between the host, environment, and the fungi that compete with one other.…”