Galactose-containing enriched root exudates of potato interfere with the growth of Pectobacterium atrosepticum

Potato (Solanum tuberosum) is a major food crop worldwide and its cultivation is fraught with difficulty. This is because potato roots and tubers are susceptible to many devastating diseases caused by soil-borne pathogens. Previous research on potato has been dedicated mainly to the tubers, with less research available on potato root structure and function, the processes of potato root exudation and the production of root border cells.

Laser confocal microscopy image showing binding of the bacterium P. atrosepticum to S. tuberosum root tip. — Laser confocal microscopy image showing binding of the bacterium *P. atrosepticum* to *S. tuberosum* root tip. Note the presence of bacteria over border cells (arrowheads and inset). Green spots correspond to bacteria. BC, border cells. Scale bars: (A) = 86 µm (A); (B) = 20 µm.

Koroney et al. show that root exudates from S. tuberosum are radically enriched by galactose-containing molecules, including arabinogalactan proteins. The composition of potato root exudates is shown to be affected in response to elicitors from Pectobacterium atrosepticum. These findings indicate that the galactose-containing polymers of potato root exudates play a central role in root-microbe interactions, interfering with the growth of P. atrosepticum.

This paper is part of the Root Biology Special Issue.