Differences in the expression profile of endo-β-(1,6)-d-galactanase in pathogenic and non-pathogenic races of Colletotrichum lindemuthianum grown in the presence of arabinogalactan, xylan or Phaseolus vulgaris cell walls

Abstract

The scope of this study was the isolation and molecular characterization of endo-β-1,6-galactanase (ebg) from pathogenic (1472) and non-pathogenic (0) races of Colletotrichum lindemuthianum cultivated with arabinogalactan, xylan or Phaseolus vulgaris cell walls as carbon sources. Characterization of the ebg cDNA and 3D protein modeling revealed typical elements of the GH30 family of galactanases. The growth of both races with glucose showed basal transcription levels of ebg. When glucose was replaced with arabinogalactan, xylan or plant cell walls, ebg transcription markedly increased in race 1472 but not in race 0. Putative DNA-binding sites for Cre, Xlnr, ACEI, PacC and Gal4 transcriptional factors were predicted in ebg genes from Colletotrichum species.