Cloning and characterization of two hydrophobin genes differentially expressed during fruit body development in Lentinula edodes.

Hydrophobins play important roles in morphogenesis and pathogenesis in fungi and fruit development in mushrooms. Two genes encoding hydrophobins (Le.hyd1 and Le.hyd2) were isolated during sequencing of random clones from a primordial cDNA library of Lentinula edodes. The nucleotide sequences of these two genes were determined. These two genes are 760 and 738 bp in length and the deduced amino acid sequences are homologous to various fungal hydrophobins with characteristic cysteine spacing. These hydrophobin genes are Class I hydrophobins judging by their conserved domains and hydropathy patterns. The transcript level of Le.hyd1 is high in primordium and that of Le.hyd2 is high in dikaryotic mycelial tissues. Poor expression of these two genes in monokaryotic parents indicates that these two genes are under mating-type regulation. We thus suggest that differential expression of these two L. edodes hydrophobins during fruit development may contribute to their distinct roles in fruiting of this mushroom.