Nonidet p-40, a novel inducer, activates cucumber disease resistance against cucumber anthracnose disease

SUMMARYThe present study found that a protein lysis buffer, used for the extraction of proteins from cells, showed efficacy in reducing the disease severity of cucumber anthracnose, which is caused by the anthracnose fungus. The lysis buffer and its individual components were examined for their function in reducing disease development of cucumber anthracnose on cucumber plants. Nonidet P-40, a nonionic detergent commonly used to isolate cell membrane complexes, was the most effective component of the lysis buffer for disease control. The treatment of cucumber plants with Nonidet P-40 at a concentration of 50 μl/l suppressed development of cucumber anthracnose, but it did not inhibit spore germination of the fungus. Cucumber plants were inoculated with the pathogen 30 min after treatment with Nonidet P-40, and a reduction in disease severity was observed. Expression of genes related to disease resistance (acidic class III chitinase, phenylalanine ammonialyase 1, peroxidase and pathogenesis-related protein 1-1a) were also examined after plants were treated with Nonidet P-40 and inoculated with the pathogen. The results indicate that Nonidet P-40 functions as a trigger for a stereotypic defence response in cucumber plants, including an increase in the expression levels of genes related to disease resistance.