# Pectobacterium atrosepticum SCRI1043 flagella mediate adherence to potato plants indirectly through motility

## TL;DR

This study investigates how flagella from Pectobacterium atrosepticum interact with potato plants, finding that motility, not direct binding, is key for attachment.

## Contribution

The study reveals that Pectobacterium flagella do not bind directly to potato roots but are essential for motility-driven adherence.

## Key findings

- Pectobacterium flagella do not directly bind to potato membrane lipids.
- Binding to potato roots depends on flagellar motility, not direct adhesion.
- Flagella-deficient or motor-deficient mutants show reduced binding to potato roots.

## Abstract

Flagella are widely distributed appendages in bacteria with well-characterized functions in motility and chemotaxis. They also interact directly with hosts and, due to their ubiquity, are potent immune elicitors for hosts from both the plant and animal kingdoms. Furthermore, flagella have been shown to facilitate attachment for several different bacterial species, including several plant-associated bacteria to plant hosts. We previously demonstrated binding of flagella from Escherichia coli to ionic lipids in plant plasma membranes for horticultural species and Arabidopsis thaliana. As such, flagella could be considered as a generic colonization factor, especially in the early stages of the interactions. Therefore, we tested whether flagella from a genetically related species of plant pathogen, Pectobacterium atrosepticum, mediated binding to its susceptible plant host, potato, in a similar manner to E. coli. Surprisingly, flagella containing the filament flagellin from P. atrosepticum did not confer any binding advantage to potato roots. Furthermore, there was no direct interaction between purified flagella and potato membrane lipids (charged or uncharged). The binding capacity of Pectobacterium to potato is dependent upon the motility function of flagella, as both flagella-deficient and motor-deficient mutants were reduced in their binding to potato roots.