Regulates Morphological Development, Ochratoxin A Production, and Fungal Pathogenicity of Food Spoilage Fungus Revealed by an Efficient Gene Targeting System.

, the producer of ochratoxin A (OTA), which is of worldwide concern, is an import fungal species in agriculture, food, and industry. Here, we got the uridine auxotrophic mutant of by deleting . The Δ could be used for bio-transformation with exogenous expression cassette as a selection marker. In order to enhance the efficiency of gene targeting, and were homologously deleted from Δ. The efficiencies of homologous replacement for Δ and Δ were 95.7 and 87.0% in the deletion of , respectively, demonstrating a drastic increase from 4.3% of the wild type (WT) strain. Furthermore, the function of was identified with deletion mutant and the control strain Δ. regulated the growth and conidiation of in response to nitrogen sources. The concentration of OTA for Δ was in the range of 19.4 to 186.9 ng/cm on all kinds of nitrogen sources. The OTA production influenced by the deletion of was different based on nitrogen sources. Pathogenicity assays on pears, grapes, salted meat, and cheese showed that acted as a negative regulator in the infection of food substrates. Therefore, the genetic methods and engineered strains enable us to substantially expand the use of , one of more than twenty OTA-producing fungi, in the study of mycotoxin biosynthesis and regulation, and consequently to aim at providing new ways for controlling this pathogen.