Genômica comparativa de espécies de Pectobacterium causadoras de podridão mole

Abstract

Soft rot is considered a significant disease in vegetable crops, and species of the genus Pectobacterium are among the main causal agents of this disease. Since 2017, species have been constantly identified, causing soft rot in various vegetables in northeastern Brazil, such as Pectobacterium brasiliense and P. aroidearum. Thus, we aim to sequence, assemble, and annotate the genomes of three isolates of P. brasiliense, one of P. aroidearum and one of P. odoriferum and perform comparative genomics analyses to identify genes responsible for pathogenicity factors with the potential to determine competitive advantage infection in different host plants. The genomic taxonomy analyzes confirmed the previously performed identifications using a polyphasic approach for the three strains of P. brasiliense (CCRMPB15, CCRMPB185 and CCRMPB596) and the strain of P. aroidearum (CCRMPA174). In contrast, the strain previously identified as P. odoriferum (CCRMPC339) was identified as P. carotovorum. The comparative genomics analyzes showed conservation of pectinases, T2SS, and quorum sensing genes, except for the expI gene, responsible for synthesizing N-acyl homoserine lactone, which presented phylogenetic relationships with a bootstrap percentage of 75%. These strains have similarities in pathogenicity factors, and apparently, the adaptation to their respective hosts is related to the synthesis gene of N-acyl homoserine lactone. Further modeling protein studies may help to understand such differences and possible relationships with their host plants. Evaluating these pathogenicity mechanisms in Pectobacterium species is essential to unveil the molecular interactions that guide the pathogen-host relationship.