![]() ![]() The cells adhere to glass slides, the glass walls of culture tubes and plastic flasks during in vitro cultivation in a liquid medium, and produce a biofilm ( Leite et al., 2002 Marques et al., 2002). fastidiosa cells in several hosts ( Tyson et al., 1985 Alves et al., 2003). ![]() Scanning electron microscopy analysis (SEM) shows vessel occlusion by the cluster of X. fastidiosa cells organize themselves into complex structures and the result is a community of cells embedded in an extracellular matrix ( Tyson et al., 1985), called a ‘biofilm’. Inside plant vessels and the insects' foregut, X. It is transmitted via grafting and xylem-feeding insects. Xylella fastidiosa is a bacterium that colonizes the xylem of various plant hosts, causing diseases such as citrus variegated chlorosis (CVC) in citrus ( Chang et al., 1993), and Pierce's disease on grapes ( Hopkins, 1989). fastidiosa gumB or gumF genes was not regulated by glucose.īiofilm, gum, knock-out, exopolysaccharide Introduction fastidiosa mutants showed a reduced capacity to form biofilm when BCYE was used as the sustaining medium, a difference not observed with PW medium. ![]() Xylella fastidiosa gumB and gumF mutants exhibited normal cell characteristics typical colony morphology and EPS biosynthesis were not altered. Xylella fastidiosa mutants were obtained by insertional duplication mutagenesis and recovered after triply cloning the cells. fastidiosa gum genes on biofilm formation and EPS biosynthesis, we produced gumB and gumF mutants. It is hypothesized that the matrix might be composed of an extracellular polysaccharide (EPS), coded by a cluster of nine genes closely related to the xanthan gum operon of Xanthomonas campestris pv. fastidiosa cells and an extracellular matrix which blocks water and nutrient transport in diseased plants. Biofilms are complex structures involving X. Xylella fastidiosa forms a biofilm inside plants and insect vectors. Xylella fastidiosa causes citrus variegated chlorosis (CVC), a destructive disease of citrus. ![]()
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