Abstract
The stem blight disease on Elaeocarpus spp. was newly identified in 2022 on E. rugosus and E. hain in Guangzhou, representing a serious stem disease that causes branch rot and cankers in Elaeocarpus species and can lead to whole-plant death in severe cases. Strain ZX-13 was isolated from Elaeocarpus rugosus stems and showed excellent antagonism against the Elaeocarpus stem blight pathogen Pseudocryphonectria elaeocarpicola. Based on morphological characteristics, physiological and biochemical results, and molecular biology analyses, the strain was identified as Erwinia phyllosphaerae. 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 Erwinia phyllosphaerae ZX-13 as an antagonistic bacterial strain for the first time, indicating substantial potential for biocontrol applications.