Gene deletion and functional analysis of the EAL domain protein VieAxoo in Xanthomonas oryzae pv. Oryzae

Abstract:

Abstract: [Objective]To better reveal the functions of key members involved in cyclic di-GMP signal metabolism pathways in the rice bacterial blight pathogen rice Xanthomonas oryzae pv. oryzae (Xoo). [Methods] vieAxoo (PXO_04753), a gene putatively encoding the EAL domain proteins was investigated by gene deletion mutation using the marker exchange, complementation and phenotypic analysis. [Result] The sequence of vieAxoo cloned from genomic DNA of the wild-type strain PXO99A was found to be highly conserved in plant-pathogenic Xanthomonas spp. VieAxoo was structurally featured with EAL and REC domains. No significant changes in virulence to rice, EPS production and flagellar motility were found in △vieAxoo compared to PXO99A, whereas remarkable changes in induction of hypersensitive responses (HR) in tobacco and biofilm formation were observed. [Conclusion] VieAxoo might function as an important regulator in cyclic di-GMP signaling and regulation of bacterial induction of HR and biofilm formation of Xoo.