Autor(es)

Souza‚ L.C.A. ; Wulff‚ N.A. ; Gaurivaud‚ P. ; Mariano‚ A.G. ; Virgílio‚ A.C.D. ; Azevedo‚ J.L. ; Monteiro‚ P.B.

• Tipo de documento: Artigo Científico
• Fonte: FEMS Microbiology Letters; v. 257, n. 2, p. 236-242, 2006.

Resumo

Xylella fastidiosa causes citrus variegated chlorosis (CVC), a destructive disease of citrus. Xylella fastidiosa forms a biofilm inside plants and insect vectors. Biofilms are complex structures involving X. fastidiosa cells and an extracellular matrix which blocks water and nutrient transport in diseased plants. 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. campestris. To understand the role of X. fastidiosa gum genes on biofilm formation and EPS biosynthesis, we produced gumB and gumF mutants. Xylella fastidiosa mutants were obtained by insertional duplication mutagenesis and recovered after triply cloning the cells. Xylella fastidiosa gumB and gumF mutants exhibited normal cell characteristics; typical colony morphology and EPS biosynthesis were not altered. It was of note that X. fastidiosa mutants showed a reduced capacity to form biofilm when BCYE was used as the sustaining medium, a difference not observed with PW medium. Unlike X. campestris pv. campestris, the expression of the X. fastidiosa gumB or gumF genes was not regulated by glucose. (AU)

• Processo FAPESP: 02/09769-0 - Analise fenotipica de mutantes de xylella fastidiosa cvc obtidos atraves de inativacao de genes codificando para exoenzimas, polissacarideos extracelulares.
• Beneficiário: Nelson Arno Wulff
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 99/04340-1 - Production and characterization of nonpathogenic mutants of xylella fastidiosa cvc-strain, the causal agent of the citrus variagated chlorosis (cvc).
• Beneficiário: Patricia Brant Monteiro
• Modalidade de apoio: Auxílio à Pesquisa - Programa GENOMA