Comparative Genomics of and pv. Strains Isolated from a Single Walnut Host Tree.

The recent report of distinct lineages of pv. and within the same walnut tree revealed that this consortium of walnut-associated includes both pathogenic and nonpathogenic strains. As the implications of this co-colonization are still poorly understood, in order to unveil niche-specific adaptations, the genomes of three strains (CPBF 367, CPBF 424, and CPBF 426) and of an pv. strain (CPBF 427) isolated from a single walnut tree in Loures (Portugal) were sequenced with two different technologies, Illumina and Nanopore, to provide consistent single scaffold chromosomal sequences. General genomic features showed that CPBF 427 has a genome similar to other pv. strains, regarding its size, number, and content of CDSs, while strains show a reduction regarding these features comparatively to pv. strains. Whole genome comparisons revealed remarkable genomic differences between pv. and strains, which translates into different pathogenicity and virulence features, namely regarding type 3 secretion system and its effectors and other secretory systems, chemotaxis-related proteins, and extracellular enzymes. Altogether, the distinct genomic repertoire of may be particularly useful to address pathogenicity emergence and evolution in walnut-associated .