Identification and Diagnostics of Plant-Symbiotic and Phytopathogenic Bacteria

Abstract

Rapid and reliable diagnostics and identification of pathogenic and symbiotic bacteria are at the top of the agenda. In the first case, they are important to control and prevent crop damages, and thus reduce economic losses. In the second, it's necessary to design and monitor quality of biofertilizer to raise its effectiveness and crop capacity. Development of accurately, rapidly, technically and commercially accessible methods remains a critical problem for the bacteria with comprehensive phylogenetic structure. In this work, we investigated pathogenic Xanthomonas and Ralstonia and symbiotic Sinorhizobium. The aim of this investigation was to examine the applicability of the novel methods for phylogenetic study, identification and diagnostics of closely related species of these genera. The conventional phenotypic and genotypic (16S rRNA, gyrB) methods were applied as referents. Novel polymerase chain reaction (PCR)-based approaches, single-adapter amplified fragment length polymorphism (saAFLP) and comparative analyses of hin-region and Xcc0006-0007 sequences, were first employed for the investigations. Phenotypic tests, 16S rRNA and gyrB analysis distinguished bacteria at the genus level, but failed to identify them to the species robustly. The new methods identified bacteria at the inter-species level more precisely. This identification agreed with the accepted genera's classifications. The only exceptions were X. fuscans & X. citri and X. perforance & X. euvesicatoria which clustered together. The further outcome of this study was achieved hin-region-based genus-specific PCR primers for the express-diagnostics of the genera. Summary, these new methods can be applied for genome-based phylogeny investigations and as convenient and accurate tools for identification and routine laboratory diagnostics of these comprehensive genera.