Antifungal Properties and Genomic Analysis of Burkholderia pyrrocinia DLL-114, an Endophyte of Camphor Tree

Camphor tree (Cinnamomum camphora) leaves are a valuable source of essential oils, but their yield is severely threatened by anthracnose caused by Colletotrichum fioriniae and C. siamense. To develop an eco-friendly alternative to chemical pesticides, we isolated a strain of Burkholderia pyrrocinia, designated DLL-114, from camphor tree roots. DLL-114 exhibited strong antagonistic activity against both pathogens, and inoculation assays demonstrated that it significantly reduced lesion areas while maintaining leaf greenness. Moreover, DLL-114 showed broad-spectrum antifungal activity against several crop pathogens, with its antifungal effects mediated by multiple antagonistic pathways. Whole-genome sequencing using Illumina and PacBio platforms revealed an 8.36-Mb genome comprising three circular chromosomes and two plasmids, with a GC content of 66.12%. The genome encodes 7,739 protein-coding genes and 21 secondary metabolite biosynthetic gene clusters, only one of which showed complete similarity to a known cluster. Notably, biosynthesis operons for gluconic acid, pyrrolnitrin, catecholate siderophores, and ornibactin were identified. These genomic features, together with metabolomic evidence, suggest that DLL-114 is a promising candidate for the production of bioactive secondary metabolites and a potential biocontrol agent for sustainable agriculture.