Akademik Veri Yönetim Sistemi
Annals of Applied Biology, 2025 (SCI-Expanded)
Bacterial canker caused by Gram-positive Clavibacter michiganensis subsp. michiganensis (Cmm) bacteria is a devastating disease of varied plant hosts. The host selection and pathogenicity are varied among different isolates based on genomic variations. Here, the genomes of 12 Cmm and a reference (PD223) isolate were successfully sequenced, assembled, and annotated utilising next-generation sequencing and comparatively analysed. The pathogenicity screens revealed that four of the isolates possess a higher disease severity index (DSI) (75%–85%); whilst some others have a lower DSI (18%–25%). Sequencing yielded an average of 7.46 Gbp for each strain covering the genome size in 2200× depth. A reference-based genome assembly approach provided nearly complete genomes for the Cmm strains. Orthologous group analysis of the sequenced genomes revealed that 2847 (83%) clusters were conserved across all Cmm strains. Additionally, 73 clusters were shared by only three strains, indicating possible gene gain events leading to genetic divergence among Cmm strains. On average, 3280 proteins were annotated for the Cmm assemblies, which indicated the pathogenicity-associated gene families: serine proteases, cellulases (celA and celB), xylanases (xysA and xysB), pectinases (pelA1 and pelA2), and tomatinase (tomA). Phylogenetic and sequence analyses revealed their high conservation among different Cmm isolates. There was no correlation between the gene repertoire and the pathogenicity observed in the plants, and there may be other factors influencing the expression of these genes or possibly other virulence genes that have not been reported.