TIDRE: An Efficient Tool for Isolating Antagonistic Endophytes and Screening Resistant Plants

Antagonistic endophytes are one of the most effective methods for crop disease biocontrol. This study reports on a convenient method termed ‘Targeted Identification of Disease-resistant Endophytes’ (TIDRE), which combines the isolation of culturable endophytic isolates from plant tissues with the screening of phytopathogen-antagonistic microbes. In addition to the direct discovery of endophytes with resistance to specific phytopathogens, the TIDRE method also facilitates the screening of endophyte-based disease-resistant crop lines. Using the TIDRE protocol, we successfully isolated endophytic bacterial strains with antagonistic activity against the pathogenic fungus Fusarium oxysporum from a traditional Chinese medicinal herb Panax notoginseng. These candidate bacteria included three Bacillus subtilis strains, a Stenotrophomonas maltophilia strain, a Pantoea brenneri strain, and a Bacillus sp. strain. Furthermore, we identified grapevine cutting clones with strong resistance to three fungal pathogens: Botrytis cinerea, F. solani, and F. graminearum, by using the TIDRE protocol. The endophytic bacterial strains (Bacillus) isolated from the highly resistant grapevine clones confer significant antagonistic effects against the fungal pathogens. Compared to existing methods, TIDRE offers superior speed and efficiency, and great potential for advancing the development and utilization of beneficial endophytic resources in sustainable agriculture.