Genome-Wide Identification and Expression Analysis of the bZIP Transcription Factors in the MycoparasiteConiothyrium minitans

The basic leucine zipper (bZIP) proteins family is one of the largest and most diverse transcription factors, widely distributed in eukaryotes. However, no information is available regarding thebZIPgene family inConiothyrium minitans, an important biocontrol agent of the plant pathogenSclerotinia sclerotiorum. In this study, we identified 34bZIPgenes from theC. minitansgenome, which were classified into 8 groups based on their phylogenetic relationships. Intron analysis showed that 28CmbZIPgenes harbored a variable number of introns, and 15 of them shared a feature that intron inserted into the bZIP domain. The intron position in bZIP domain was highly conserved, which was related to recognize the arginine (R) and could be treated as a genomic imprinting. Expression analysis of theCmbZIPgenes in response to abiotic stresses indicated that they might play distinct roles in abiotic stress responses. Results showed that 22CmbZIPgenes were upregulated during the later stage of conidial development. Furthermore, transcriptome analysis indicated thatCmbZIPgenes are involved in different stages of mycoparasitism. Among deletion mutants of fourCmbZIPs (CmbZIP07, -09, -13, and -16), only Delta CmbZIP16mutants significantly reduced its tolerance to the oxidative stress. The other mutants exhibited no significant effects on colony morphology, mycelial growth, conidiation, and mycoparasitism. Taken together, our results suggested thatCmbZIPgenes play important roles in the abiotic stress responses, conidial development, and mycoparasitism. These results provide comprehensive information of theCmbZIPgene family and lay the foundation for further research on thebZIPgene family regarding their biological functions and evolutionary history.