Complete Genome Sequencing of Erwinia phyllosphaerae ZX-13, a Novel Biocontrol Agent to Against the Stem Blight Pathogen Pseudocryphonectria elaeocarpicola in Elaeocarpus spp.

The stem blight disease on <i>Elaeocarpus</i> spp. was newly identified in 2022 on <i>E. rugosus</i> and <i>E. hain</i> in Guangzhou, representing a serious stem disease that causes branch rot and cankers in <i>Elaeocarpus</i> species and can lead to whole-plant death in severe cases. Strain ZX-13 was isolated from <i>Elaeocarpus rugosus</i> stems and showed excellent antagonism against the <i>Elaeocarpus</i> stem blight pathogen <i>Pseudocryphonectria elaeocarpicola.</i> Based on morphological characteristics, physiological and biochemical results, and molecular biology analyses, the strain was identified as <i>Erwinia phyllosphaerae.</i> Whole-genome sequencing and annotation indicate that strain ZX-13 has a high-quality draft assembly of 4,686,433 bp, with a GC content of 53.85%, encoding 4189 genes, 86 tRNA, 22 rRNA, and 110 ncRNA. Eight antifungal enzymes from the GH family may be crucial factors to its antagonistic activity. Using antiSMASH 7.1.0, the ZX-13 genome predicted eight BGCs (RiPPs, NRPs, terpenes, etc.), with one showing 100% similarity to carotenoid biosynthesis. Novel candidates include an O-antigen, hassallidin C, and lankacidin C. The study identified <i>Erwinia phyllosphaerae</i> ZX-13 as an antagonistic bacterial strain for the first time, indicating substantial potential for biocontrol applications.