Dickeya solani is a bacterium that causes blackleg and soft rot in potato crops. Its symptoms are often indistinguishable from those caused by Pectobacterium but is more virulent, causing disease from lower levels of inoculum and spreading through the plant more effectively. It was first discovered in the Netherlands in 2005, before spreading rapidly, causing €25–30 million of damage annually by 2010. Three cases appeared in Scotland in 2009 and one in 2010. Host and symptoms The host for Dickeya solani is the potato plant (Solanum tuberosum). Dickeya spp. can be the causal agents of soft rots and black leg. The symptoms that this bacteria causes can at times not be easily distinguished from the symptoms caused by Pectobacterium spp, since both pathogens induce a rotting of the plant tissue and black leg symptoms on the host. Black leg symptoms consist of wet, black rot on the stem that spread up from the original seed tuber. Symptoms of a Dickeya solani infection can include wilts and soft rots. The wilts occur when the bacterial pathogen invades the vascular system of the plant. The wilt symptoms can progress rather rapidly. Soft rots can be identified as soft, watery plant tissue with small, wet stem lesions. Pathogenesis Dickeya solani can cause disease more effectively in temperate climates in comparison to other Dickeya spp. Furthermore, Dickeya solani is more aggressive in causing blackleg than other species. Dickeya solani can induce disease at lower inoculum levels. One reason for this is that Dickeya solani produces more cell wall degrading enzymes compared to other Dickeya spp. Dickeya spp. have virulence factors such as extracellular enzymes, type III secretion systems, and phospholipases. Dickeya spp. have cell wall degrading enzymes such as cellulases and proteases that digest the plant cell wall and allow the pathogen to infect the plant. The usage of cell wall degrading enzymes is sometimes categorized as a “brute force” method. However, there are less blunt ways that Dickeya spp. can attack the host, the type III secretion system can code for hypersensitive response and pathogenicity (hrp) genes. In some Dickeya species the hrp genes are involved early on in pathogenesis. Dickeya solani can code for zeamine, which is a phytotoxin. The genes for coding zeamine are not well-conserved among the Dickeya spp. However these synthesis genes are similar in Dickeya zeae and Dickeya solani. During the evolution of Dickeya pathogens these genes were