Effect of temperature stress on the response of potato (Solanum tuberosum) to soft-rot (Erwinia) infection
Potato (Solanum tuberosum), a global food crop is susceptible to soft rot infection by the pectolytic bacteria, Pectobacterium and Dickeya species, leading to substantial losses worldwide. Two potato varieties Atlantic (heat sensitive, foliar disease resistant) and Norchip (heat tolerant, susceptible to foliar disease) were used to investigate simultaneously the relationship between temperature stress and the establishment and spread of soft rot infection on the host. Macerated tissues were collected from infected tubers and quantified. Media supplemented with extracts from tubers and stems from both varieties were inoculated with P. carotovorum , strain KD 100 and its hypervirulent transposon Tn5 mutant, KD 201. The supernatants of overnight bacterial cultures were assayed for pectate lyase (Pel) activity. The maximum tuber infection occurred after stress level of 16 hours incubation at 40°C. Broader infection was observed in the Atlantic variety. Higher Pel activity was noted in samples containing extract obtained from unstressed plants while extracts from the Atlantic variety induced more Pel activity. This study showed that host temperature stress does affect the level of infection in tubers and influences the amount of enzyme produced by the pathogen.
Christy D Gibson,
"Effect of temperature stress on the response of potato (Solanum tuberosum) to soft-rot (Erwinia) infection"
ETD Collection for Tennessee State University.