Genome size and macrorestriction map of Xanthomonas campetris pv. glycilnes YR32 chromosome

Abstract

Xur~rhoiiior~rcrsa n~p~striiss a n i~nport:int plant pathogeniq bacteriu~liw hich causes severe diseases in a wide varicty of plant species. We have generated a macrorestriction map of the X. ccuill~estris( ~.vorro/)or/i.p~v). g(~>~i/clh~ro:mi osome employing pulsed-field gel electrophoresis (PFGE). Restriction endonubleases Pucl (5'-TTAATTAA), PnwI (5'-GTTTAAAC) and S ~ t , o l (5'-ATTTAAAT) digested the chromosomal DNA into three, five, and five fragments, respectively. In addition, intronencoded restriction endonuclease I-CeuI was employed to locate the position of the23S rRNA genes (rrlA and rrlB). All of the generated restriction fragments were aligned along the ch~omosorne using multiple restriction enzyme digestion and twodimensional PFGE (2-D PFGE) in conjunction with Southern hybridization analysis. This physical map construction has revealed a single eircular chromosome with a size of approxibately 5 Mb. Two rRNA genes were localized on the chromosome map. Several genes involved in pathogenesis (xpsD, opsX, a~lbputa)s well as genes involved in the biosynthesis of xanthan gum (xanAB, rfhCDAB) were also localized. O 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved Keyluords: Xantl~omonas; Pulsed-field gel electrophoresis; MappinB; Circular chromosome