Journal de pathologie végétale et de microbiologie

Abstrait

Endophytic Bacteria Associated to Sharpshooters (Hemiptera: Cicadellidae), Insect Vectors of Xylella fastidiosa Subsp. pauca

Cláudia Santos Gai, Francisco Dini-Andreote1, Fernando Dini Andreote, João Roberto Spotti Lopes, Thomas Albert Miller, João Lúcio Azevedo and Paulo Teixeira Lacava

Xylella fastidiosa subsp. pauca causes citrus variegated chlorosis (CVC) disease in Brazil, resulting in significant production losses in the citrus industry. X. fastidiosa subsp. pauca is mainly transmitted by three species of sharpshooters (Hemiptera: Cicadellidae) in Brazil; Dilobopterus costalimai (Young), Acrogonia citrina Marucci & Cavichioli and Oncometopia facialis (Signoret). We identified bacterial communities associated with the heads of surface-sterilized insect vectors of X. fastidiosa subsp. pauca that were collected from CVC affected citrus groves in Brazil. Bacteria were isolated and analyzed by amplified ribosomal DNA restriction analysis (ARDRA) and sequencing, revealing the presence, among the most abundant genera, of the well-known citrus endophytes Methylobacterium spp. and Curtobacterium spp. Specific PCR systems for the detection of these genera indicated high frequencies of presence of these bacteria in sharpshooters. The remaining bacterial community was compared in distinct vector species and at different period of the year by denaturing gradient gel electrophoresis (DGGE), showing its responsiveness to the climate change over the year. These results represent a new basis for the knowledge about the interaction symbiotic-pathogenic bacteria inside insect vectors and provide a basis for further work on the biocontrol of plant bacteria like X. fastidiosa.