Pectobacterium brasiliense 1692 Chemotactic Responses and the Role of Methyl-Accepting Chemotactic Proteins in Ecological Fitness

Abstract

To adapt to changing environmental niches, bacteria require taxis, a movement toward or away from a stimulus (ligand). Chemotaxis has been studied in some members of the Soft Rot Pectobacteriaceae (SRP), particularly members of the genus Dickeya. On the contrary, there are fewer studies on this topic for the other genus in the SRP group, namely Pectobacterium. This study evaluated chemotactic responses in Pectobacterium brasiliense (Pb 1692) to various ligands. A total of 34 methyl-accepting chemotactic proteins (MCPs) were identified in the Pb 1692 genome and the domain architectures of these MCPs were determined. Four Pb 1692 MCPs previously shown to be differentially expressed during potato tuber infection were selected for further functional characterization. Toward this end, Pb 1692 mutant strains each lacking either AED-0001492, AED-0003671, AED-0000304, or AED-0000744 were generated. Two of these mutants (AED-0001492 and AED-0003671), were attenuated in their ability to grow and respond to citrate and are thus referred to as MCPcit2 and MCPcit1, respectively, while the other two, AED-0000304 (MCPxyl) and AED-0000744 (MCPasp), were affected in their ability to respond to xylose and aspartate, respectively. Trans-complementation of the mutant strains restored swimming motility in the presence of respective ligands. The four MCP mutants were not affected in virulence but were significantly attenuated in their ability to attach to potato leaves suggesting that ecological fitness is an important contribution of these MCPs toward Pb 1692 biology.

A Switch from Latent to Typical Infection during Pectobacterium atrosepticum—Tobacco Interactions: Predicted and True Molecular Players

“…On the other hand, symptomatic Pectobacterium ssp.-caused infections are always associated with a strong upregulation of the JA pathway, which does not prevent disease development [13,24,25,55,57]. Additionally, JA serves as a chemoattractant for P. brasiliense [58]. Furthermore, the increase in plant resistance to Pectobacterium species due to various treatments is associated with a shift in the JA-SA balance in favor of SA [41,[59][60][61].…”

Self-Assembly of a Dipeptide with a Reduced Amount of Copper into Antifungal and Antibacterial Particles

“…P. brasiliense is the primary pathogenic factor contributing to the global prevalence of soft rot and blackleg diseases in potato tubers and stems. 4 These bacteria are known to produce large quantities of pectic enzymes, which break down pectin in plant cell walls, leading to cellular damage and collapse. P. brasiliense bacteria are present on plant surfaces and in soil, and they can enter plants through wounds or natural openings like lenticels.…”