UNLABELLED N-Acetylglucosamine (GlcNAc), the main component of chitin and a major constituent of bacterial peptidoglycan, is present only in trace amounts in plants, in contrast to the huge amount of various sugars that compose the polysaccharides of the plant cell wall. Thus, GlcNAc has not previously been considered a substrate exploited by phytopathogenic bacteria during plant infection. Xan...

Xanthomonas campestris pv. campestris is the etiological agent of black rot of crucifers, a disease of major economic importance which is a threat to the production of cruciferous crops in many areas of the world [1], During a recent investigation of this patho­ gen for the production of phytotoxic metabolites in liquid culture we observed the biotransformation of certain amino acid constituent...

Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and...

A violacein-producing bacterial strain was isolated and identified as a relative of Duganella violaceinigra YIM 31327 based upon phylogenetic analyses using the 16S rRNA, gyrB and vioA gene sequences and a fatty acid methyl ester (FAME) analysis. This new strain was designated D. violaceinigra str. NI28. Although these two strains appear related based upon these analyses, the new isolate was ph...

Citrus canker (caused by Xanthomonas citri subsp. citri (ex Hasse) Gabriel et al.) is a disease that affects several citrus species and causes erumpent, necrotic lesions on leaves, shoots, branches, and fruit. Yield loss due to fruit and leaf drop can be substantial, and on fruit the unsightly blemishes leads to reduced marketability (14,15,34). The disease is widespread in citrus growing regio...

The gram-negative bacterium Xanthomonas campestris pv. vesicatoria is the causal agent of spot disease in tomato and pepper. Plants of the tomato line Hawaii 7981 are resistant to race T3 of X. campestris pv. vesicatoria expressing the type III effector protein AvrXv3 and develop a typical hypersensitive response upon bacterial challenge. A combination of suppression subtractive hybridization a...

It is widely appreciated that short tandem repeat (STR) variation underlies substantial phenotypic variation in organisms. Some propose that the high mutation rates of STRs in functional genomic regions facilitate evolutionary adaptation. Despite their high mutation rate, some STRs show little to no variation in populations. One such STR occurs in the Arabidopsis thaliana gene PFT1 (MED25), whe...

Genetic dissection of the mamAB and mms6 operons reveals a gene set essential for 1 magnetosome biogenesis in Magnetospirillum gryphiswaldense 2 3 4 5 Anna Lohße, Sarah Borg, Oliver Raschdorf, Isabel Kolinko, Éva 6 Tompa, Mihály Pósfai, Damien Faivre, Jens Baumgartner, and Dirk 7 Schüler* 8 9 10 11 12 13 14 1 Ludwig-Maximilians-Universität München, Dept. Biologie I, Mikrobiologie, 15 LMU Biozen...

Xanthomonas campestris pv. campestris possesses a low level of beta-galactosidase and therefore is not able to grow and produce significant amounts of xanthan gum in a medium containing lactose as the sole carbon source. In this study, a beta-galactosidase expression plasmid was constructed by ligating an X. campestris phage phi LO promoter with pKM005, a ColE1 replicon containing Escherichia c...