Specific Reconstruction on pRC Plasmid to Facilitate Its Universal Chromosomal Integration in Different Species Complex Strains.

The pRC system is an efficient tool for genetic studies in , ensuring direct insertion of foreign gene elements into chromosome downstream of . This system is designed for double recombination across and the downstream region, which considerably simplifies genetic studies of complementation, overexpression, pathogenicity, and in-vivo promoter activity assays with monocopy in , one of the most destructive plant-pathogenic bacteria worldwide. is extremely heterogeneous and is currently referred to as a species complex (RSSC). The gene is greatly conserved, but its downstream regions are mostly different in the RSSC, which limits the application of the current pRC plasmid in the RSSC. We compared all existing 132 genome sequences in a precise genomic downstream region and confirmed that the pRC system is appropriate for application of chromosomal integration in all RSSC strains but needs respective reconstruction on current pRC plasmids, since downstream regions are greatly variable in the RSSC. RSSC strains can be grouped according to identical downstream regions. This grouping provides valuable information for gene insertion in this chromosomal region, as it facilitates universal application of the pRC system in RSSC strains.