Pectobacterium jejuense sp. nov. Isolated from Cucumber Stem Tissue

Area of Science:

• Microbiology
• Plant Pathology
• Bacteriology

Background:

• Pectobacterium species are significant plant pathogens causing soft rot diseases in various crops.
• Accurate identification and characterization of novel strains are crucial for disease management and understanding bacterial evolution.

Purpose of the Study:

• To isolate and characterize a novel Pectobacterium-like strain from diseased cucumber.
• To determine the phylogenetic position and taxonomic status of the novel strain.
• To assess the pathogenicity of the novel strain on cucumber plants.

Main Methods:

• Isolation and phenotypic characterization of strain 13-115^T.
• 16S rRNA gene sequencing and multilocus sequence analysis (MLSA) using dnaX, leuS, and recA genes.
• In silico DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) calculations.
• Genome sequencing and fatty acid analysis.
• Pathogenicity assays on cucumber plants.

Main Results:

• Strain 13-115^T, isolated from diseased cucumber, exhibited typical Pectobacterium characteristics.
• Phylogenetic analyses placed strain 13-115^T in a distinct lineage within the Pectobacterium genus.
• Low in silico DDH (<60.6%) and ANI (<94.9%) values differentiated it from known Pectobacterium species.
• The strain induced soft rot symptoms in cucumber, fulfilling Koch's postulates.

Conclusions:

• Strain 13-115^T represents a new species within the genus Pectobacterium, named Pectobacterium jejuense sp. nov.
• Pectobacterium jejuense is a causal agent of soft rot in cucumber.
• This discovery expands the known diversity of Pectobacterium pathogens affecting agricultural crops.