Identification and characterization of cDNA sequences encoding the HIS3 and LEU2 genes of the fungus Alternaria tenuissima.

Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans. In this study, through a yeast genetic approach, cDNA sequences were isolated and characterized for the AtHIS3 and AtLEU2 genes. AtHIS3 cDNA encodes a protein of 238 amino acids, while AtLEU2 cDNA encodes a protein of 363 amino acids. Based on the phylogenetic analysis of amino acid sequences of AtHis3p and AtLeu2p, A. tenuissima is closely related to the plant pathogenic fungus Phaeosphaeria nodorum. This study provides two genetic markers for studies of functions of genes regulating development, morphology, and virulence of A. tenuissima.