Study on biocontrol potential of volatile organic compounds produced by Pseudomonas atacamensis GZ-3 on poplar anthracnose

Poplar anthracnose caused by Colletotrichum gloeosporioides is one of the major forest diseases worldwide, causing incalculable losses in forestry production every year. In this study, an endophytic bacterium with significant antagonistic activity against C. gloeosporioides was isolated from Populus canadensis leaves, identified and named Pseudomonas atacamensis GZ-3. The specific biological functions of strain GZ-3 were analyzed using whole genome sequencing. The volatile organic compounds (VOCs) produced by strain GZ-3 had good antifungal activity against C. gloeosporioides . These VOCs could effectively inhibit mycelial growth and conidial germination of C. gloeosporioides . In addition, metabolomics analysis revealed that VOCs could help poplar resist infection of C. gloeosporioides by inducing the synthesis of flavonoids in poplar. 3-methyl-1-butanol and 2-heptanone were the main antifungal compounds in VOCs. Therefore, Pseudomonas atacamensis GZ-3 had good potential for biocontrol. This study provided a new strategy for the biological control of poplar anthracnose. • Volatile organic compounds (VOCs) produced by stain GZ-3 have antifungal activity. • VOCs can disrupt fungal hyphae structure and inhibit spore germination. • VOCs can induce the synthesis of flavonoids in poplar tissue culture seedlings. • VOCs can help poplar effectively resist anthracnose infection. • 3-methyl-1-butanol and 2-heptanone are the primary antifungal components in VOCs.