HYDROPHOBIN GENE SRH1, EXPRESSED DURING SPORULATION OF THE BIOCONTROLAGENT TRICHODERMA-HARZIANUM

A cDNA clone encoding a spore-related hydrophobin, SRHI, was isolated from a cDNA bank prepared from mRNA induced in sporulating cultures of Trichoderma harzianum by heterologous hybridization using the hfb2 ge ne encoding a spore-bound hydrophobin of Trichoderma reesei as a probe . Based on sequence similarity the predicted protein was identified as a new member of the class-II hydrophobin family. Including the signal sequences, SRHI has 65% and 56% amino-acid similarity with the T. ree sei hydrophobins HFBII and HFBI, respectively, being less similar with other hydrophobins. srh1 is present as one copy in the T. harzianum g enome. It is highly expressed under sporulating conditions, both in su bmerged as well as in aerial cultures. Moreover, nutrient limitation i nduces srh1 expression.