Proteins Involved in the Interaction of Potato Tubers with P ectobacterium atrosepticum : a Proteomic Approach to Understanding Partial Resistance

Potato can be severely affected by various pathogens, including P ectobacterium atrosepticum , the cause of bacterial soft rot on tubers and of blackleg on stems. To date, no complete resistance to P . atrosepticum is available, so that only cultivars exhibiting partial resistance can be found. The mechanistic basis of this type of resistance is still poorly understood. A proteomic approach was thus developed to identify pathways specifically activated during the interaction between potato tubers and P . atrosepticum . Protein profiles on silver‐stained gels in the 5–8 p H range were obtained from healthy and infected tubers from two cultivars differing for resistance level and analyzed by 2‐ DE and nano‐ LC ‐ MS / MS . Thirteen proteins were differentially up‐regulated in the partially resistant cv. K erpondy; by contrast, no significant differences in protein profiles of inoculated and control tubers were observed in the susceptible cv. B intje. Mass spectrometry and database searching showed that these proteins are involved in energetic metabolism (glyceraldehyde‐3‐phosphate dehydrogenase, 2‐phosphoglycerate dehydratase or enolase, fructose biphosphate aldolase and ATP ase α subunit), cytoskeleton structure (actin), protein catabolism (cysteine protease inhibitor) and patatins or patatin precursors. Their involvement in defence responses of cv. K erpondy to P . atrosepticum is discussed. Proteomic appears as an efficient approach to have insight into the mechanisms and pathways leading to potato resistance against P .  atrosepticum .