Solamun tuberosum (potato) is currently one of the most important food crop in the world. Erwinia carotovora subsp. carotovora (E.c.c.) is one of the etiological agents of the soft rot disease, causing significant economical loses in this crop, both during the harvest as well as during storage of tubers. Four potato cDNAs have been previously isolated based on the expression pattern of the corresponding genes. Their transcripts accumulate in response to treatment of plants with the secreted cell wall-degrading enzymes produced by E.c.c. as well as treatment with small oligogalacturonides, which are components of the plant cell wall. All four genes reach their maximum expression one hour after treatment with these elicitors suggesting that they may be involved in the first stages of the local defense response triggered by E.c.c. The cDNAs were named PRK 1, 2, 3 and 4 (potato receptor-like kinase) as their deduced amino acid sequence has high similarity with transmembrane receptors containing a serine/threonine kinase intracellular domain. The proteins also contain an extracellular domain with a characteristic bi-modular cysteine pattern that defines them as a novel family of receptors. We approached the functional studies of this family of receptors by means of genetic engineering, for which over-expressing and silencing transformation vectors for one of these genes (PRK2) were constructed and subsequently transformed into Solanum tuberosum subsp. tuberosum cv. Bintje. To perform studies at protein level, the sequence encoding the extracellular domain of PRK2 was cloned into the bacterial expression vector pQE-60, and the resulting recombinant protein was used to generate polyclonal antibodies.