Inhibition of rice (Oryza sativa L.) seedling elongation by a Pseudomonas fuscovaginae toxin

Summary The effects of a Pseudomonas fuscovaginae toxin, on germination, root formation and seedling elongation, after soaking rice grains in the toxin prior to sowing, was investigated. The toxin enhanced germination, but had no apparent effect on the number of roots of the seedlings. It induced a drastic inhibition of seedlings elongation correlated to varieties susceptibility to the disease in the rice field. After denaturation of the bioactive compounds of the extract, all the previously observed effects were lost. Using the toxin and the present test, could be a reliable tool for screening genotype susceptibility to P. fuscovaginae disease.