Disruption of the subtilase gene, albin1, in Ophiostoma piliferum

Wood sapstaining fungi produce multiple proteases that break down wood protein. Three groups of subtilases have been identified in sapstaining fungi; however, it is not known if these groups have distinct physiological roles (B. Hoffman and C. Breuil, Curr. Genet. 41:168-175, 2002). In this work we examined the role of the subtilase Albin1 from Ophiostoma piliferum. Reamplification of cDNA ends PCR was used to obtain the albin1 gene sequence. The encoded subtilase is probably extracellular and involved in nutrient acquisition. This gene was disrupted with an Agrobacterium tumefaciens-mediated transformation system. Two of the disruptants obtained had significantly lower levels of proteolytic activity, slower growth in bovine serum albumin, and significantly reduced growth on wood. Thus, albin1 plays an important role in O. piliferum's ability to acquire nitrogen from wood proteins.