Candidates for Symbiotic Control of Sugarcane White Leaf Disease

The leafhopperMatsumuratettix hiroglyphicus (Matsumura) is the most important vector of a phytoplasma pathogen causing sugarcane white leaf (SCWL) disease. The purpose of this study was to evaluate candidate bacterial symbionts for possible use as vehicles in the control of the disease. 16S rRNA bacterial genes were amplified from whole bodies ofM. hiroglyphicus leafhoppers and analyzed by cloning and sequencing. Two dominant groups were found: one belonged to theBetaproteobacteria that did not closely match any sequences in the database and was named bacterium associated withM. hiroglyphicus (BAMH). Another one found to be abundant in this leafhopper is “Candidatus Sulcia muelleri” in the orderBacteroidetes , which was previously reported in the insect members of the Auchenorrhyncha. MostM. hiroglyphicus leafhoppers carry both BAMH and “Ca . Sulcia muelleri.” Fluorescentin situ hybridization showed that BAMH and “Ca . Sulcia muelleri” colocalized in the same bacteriomes. BAMH was present in the midgut and ovaries of the leafhopper and was found in all developmental stages, including eggs, nymphs, and adults. Because BAMH appears to be specific for the SCWL vector, we evaluated it as a candidate for symbiotic control of sugarcane white leaf disease.