Abstract
Bacterial plant pathogens belonging to the Xanthomonas genus are adapted to their host plants and are not known to colonize other environments. Xanthomonas colonize host parts such as leaves, stems and roots before entering vascular tissues and engaging in an invasive pathogenic phase. These bacterial strains have evolved strategies to adapt to life in this environment. The host-pathogen interactions of Xanthomonas vasicola (Xv) need to be well understood to properly map the target genes in the host and pathogen so as to understand the mechanism of resistance. Genotypic characterization, based on the analysis of restriction fragment length polymorphism of virulence factor fragment products was performed on members of the X. vasicola pv. musacearum (Xcm) and X. vasicola pv. vasculorum (Xvv) from varying geographical locations. The study showed that Xcm and Xvv are different from each other based on amplification of virulence factors within fragments of their DNA. Bacterial strains of similar species can have unique Type four pili (Tfp) and Tfp pilus assembly protein PilF a fimbrial biogenesis protein was amplified in all Xanthomonas strains except NCPPB1131 only. Type III effector protein RipT was confirmed to be present in all strains of Xcm and Xvv but not NCPPB1131 and NCPPB1132. All the Xcm and Xvv strains under test yielded bands of type III effector HopAF1 except Xvv206, NCPPB1131 and NCPPB1132. YopJ type III secretion system effector protein hybridizes in DNA of all Xcm strains tested but not in NCPPB1131 or NCPPB1132. This study confirmed the predicted presence or absence of virulence factors especially effectors across bacterial strains and within strains of the same species and other clusters conserved in gram negative bacteria. Key words: Banana, effectors, pathogen-host, Xanthomonas wilt, Xanthomonas campestris, Xanthomonas vasicola.
Highlights
Banana production in Eastern Africa is on the decline due to diseases Banana Xanthomonas Wilt (BXW)(Kubiriba et al, 2012; Tushemereirwe et al, 2004)
Virulence factors were categorized into lipopolysaccharides (LPS), type iv pilus proteins (Tfp) and type three secretion system (TTSS) proteins for analysis across 8 strains of X. vasicola pv. musacearum (Xcm), 2 strains of National Collection of Plant Pathogenic Bacteria (NCPPB) and 3 X. vasicola pv. vasculorum (Xvv) strains
In this study we have shown that Xcm and Xvv strains under test differ in their Type four pili (Tfp) composition as was earlier predicted by Studholme et al (2010)
Summary
Banana production in Eastern Africa is on the decline due to diseases Banana Xanthomonas Wilt (BXW)(Kubiriba et al, 2012; Tushemereirwe et al, 2004). The draft genome analysis of the two bacteria species (Xcm4381 and Xvv702) revealed several genetic differences between the two strains that might be important for host specificity, virulence and epiphytic fitness, including differences in the repertoires of secreted and translocated effector proteins, Tfp and enzymes for lipopolysaccharide biosynthesis (Studholme et al, 2010) They both encode homologues of the candidate T3SS effectors including AvrBs2, AvrGf1, HopW1; HopAF1; PilvD; RipT; YopT-like cysteine protease and a variety of homologues of XopF, XopK, XopL, XopN, XopP, XopQ, XopR, XopX, XopZ, XopA, XopB, XopG, XopH, XopI, XopY, XopAA, XopAD, XopAE and XopAK, which are conserved in a subset of Xanthomonas genomes. Such differences in effector repertoires are said to be significant for host adaptation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
