From Xanthomonas campestris pv. phaseoli, we have isolated by two independent methods genes involved in peroxide detoxification (ahpC and ahpF), a gene involved in peroxide sensing and transcription regulation (oxyR), and a gene of unknown function (orfX). Amino acid sequence analysis of AhpC, AhpF, and OxyR showed high identity with bacterial homologs. OrfX was a small cysteine-rich protein wi...

Xanthomonas oryzae pv. oryzae causes bacterial blight, a serious disease of rice. Our analysis revealed that the X. oryzae pv. oryzae genome encodes genes responsible for iron uptake through FeoB (homolog of the major bacterial ferrous iron transporter) and a siderophore. A mutation in the X. oryzae pv. oryzae feoB gene causes severe virulence deficiency, growth deficiency in iron-limiting medi...

DNA polymorphism analysis and pathogenicity assays were used to characterize strains of Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola collected from rice leaves in West Africa. Restriction fragment length polymorphism (RFLP), repetitive sequence-based polymerase chain reaction, fluorescent amplified fragment-length polymorphism (FAFLP) analyses were assessed for molecular c...

As causal agents of bacterial wilt in pastures and meadows, bacteria of the species Xanthomonas translucens are a serious issue in forage grass production. So far, only little is known about host-pathogen interactions at the molecular level and the lack of comprehensive genome data impeded targeted breeding strategies towards resistant forage grass cultivars. Here we announce the draft genome s...

Xanthomonas arboricola pv. pruni is a quarantine bacterial pathogen that threatens peach production by causing necrotic spots on leaves and fruits, thus with the potential of severely reducing yields. The current understanding of the host plant defense responses to the pathogen is very limited. Using whole transcriptome sequencing, differential gene expression was analyzed at two time points, 2...

Xanthomonas citri pv. vignicola strains cause bacterial blight of the legume crop cowpea. We report whole-genome sequences of three X. citri pv. vignicola strains obtained using PacBio single-molecule real-time sequencing. Such genomic data provide new information on pathogenicity factors, such as transcription activator-like effectors.

Guggal is tapped for extraction of medicinally important oleo-gum-resin (guggul) by inoculating the stem bark with natural gum suspension containing pathogenic bacterium Xanthomonas axonopodis pv. commiphorae (Xac). The tree dies in the process. In absence of any specific medium for isolation of Xac, it is difficult to assess spread of the pathogen within the plant. A PCR based molecular detect...

Xanthomonas campestris pv. campestris is the causal agent of black rot on Brassicaceae. The draft genome sequences of three strains (CN14, CN15, and CN16) that are highly aggressive on Arabidopsis have been determined. These genome sequences present an unexpected genomic diversity in X. campestris pv. campestris, which will be valuable for comparative analyses.

This chapter describes methods for targeted knockouts using marker exchange mutagenesis and complementation of the Gram-negative bacteria Xanthomonas oryzae pv. oryzae. We have used these methods to demonstrate that type I secretion and modification systems are involved in avrXa21 activity of X. oryzae pv. oryzae.