Molecular cloning, sequence analysis and expression of a novel gene induced by near-UV light in Bipolaris oryzae

Abstract.

A cDNA clone derived from a novel gene (uvi-1) that is inducible by near-UV light was isolated by a differential screening procedure from a cDNA library of the fungus Bipolaris oryzae and characterized further. Sequence analysis of the clone revealed that uvi-1 encodes a protein with a putative molecular mass of 17 kDa; the UVI-1 protein shows significant similarity to a putative protein encoded by a cDNA which is expressed during appressorium formation in the rice blast fungus, Magnaporthe grisea. The corresponding genomic clone was also isolated, and Southern analysis of genomic DNA indicated the presence of a single copy of the uvi-1 gene in B. oryzae. Northern analysis showed that the uvi-1 transcripts are induced by exposure to near-UV light, but not by blue or red light. Furthermore, accumulation of uvi-1 transcripts is observed during differentiation of the appressorium.