Cerato-ulmin (CU) is a class II hydrophobin protein of about 7600 Da, produced by the Ascomycota Ophiostoma ulmi (Buisman) Nannf., O. novo-ulmi Brasier and O. himal-ulmi Brasier M. D. Mehrotra. O. ulmi and O. novo-ulmi are responsible for the Dutch elm disease (DED) that in the 20th century destroyed most of the elms native in Europe and North America (Ulmus minor Miller, U. glabra Huds., U. procera Salisb., U. americana L., U. rubra Muhl.), whereas O. himal-ulmi is present in Asia. CU accumulates in the cell walls of DED fungi and is abundantly released in the liquid culture medium with the exception of O. ulmi known to be a scarce or nil CU producer. It has been suggested that CU plays a key role in different phases of DED. However, the relationship between CU production and virulence of DED pathogens is still debated. In another ophiostomatoid species, O. quercus, non pathogenic towards elm trees, an immunologically CU-related protein was present in the mycelial cell wall, but not in the culture medium. Moreover, a DNA sequence that cross-hybridized with an O. novo-ulmi cu gene fragment was detected, thus suggesting the presence of a cu-ortologous gene in O. quercus. In the present work we report the cloning and sequencing of the cu gene from O. quercus. Furthermore, the protein has been partially purified from the mycelium and characterized.
Ophiostoma quercus produces a cerato-ulmin-homologous protein
BERNARDI, RODOLFO;
2006-01-01
Abstract
Cerato-ulmin (CU) is a class II hydrophobin protein of about 7600 Da, produced by the Ascomycota Ophiostoma ulmi (Buisman) Nannf., O. novo-ulmi Brasier and O. himal-ulmi Brasier M. D. Mehrotra. O. ulmi and O. novo-ulmi are responsible for the Dutch elm disease (DED) that in the 20th century destroyed most of the elms native in Europe and North America (Ulmus minor Miller, U. glabra Huds., U. procera Salisb., U. americana L., U. rubra Muhl.), whereas O. himal-ulmi is present in Asia. CU accumulates in the cell walls of DED fungi and is abundantly released in the liquid culture medium with the exception of O. ulmi known to be a scarce or nil CU producer. It has been suggested that CU plays a key role in different phases of DED. However, the relationship between CU production and virulence of DED pathogens is still debated. In another ophiostomatoid species, O. quercus, non pathogenic towards elm trees, an immunologically CU-related protein was present in the mycelial cell wall, but not in the culture medium. Moreover, a DNA sequence that cross-hybridized with an O. novo-ulmi cu gene fragment was detected, thus suggesting the presence of a cu-ortologous gene in O. quercus. In the present work we report the cloning and sequencing of the cu gene from O. quercus. Furthermore, the protein has been partially purified from the mycelium and characterized.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
