Bioinformatic analysis of the ABC transporter protein family and their function in Penicillium digitatum

ATP-binding cassette transporter (ABC transporter) has prominent effects on the normal growth, development, substance transport and drug detoxification of organisms. However, the function of most of the ABC family members in filamentous fungi remains unknown. In the present research, 171 ABCs were identified from fruit postharvest pathogenic Penicillium spp. fungi including P. digitatum, P. expansum and P. italicum, of which 45 were from P. digitatum. Bioinformatics analysis showed that all 45 PdABCs had ABC_tran domain, belonging to seven subfamilies and containing 1-12 introns, distributed on six chromosomes of P. digitatum. The transcriptome data of spore germination, infection and sodium dehydroacetate (SD) inhibition showed that 43 PdABCs were detected as expressed in at least one stage, 6 PdABCs were all significantly differenially expressed during spore germination, infection or SD repression, five, eight and six PdABCs were significantly differentially expressed at the spore germination, infection and SD repression stages, respectively. RT-qPCR experiments further validated these six co-differentially expressed PdABCs. Cis-acting element (CAE) analysis showed that C2H2, C6 and Heat shock factors family-specific binding elements were highly present in their promoters, and the interaction reg-ulatory network analysis indicated that there were interactions between PdABCs and PdABCs, major facilitator superfamily (MFS) transporter proteins, cytochrome P450 proteins, TFs (PdRING1,PdHeat1,PdbZIP1, PdzincC6). This study contributes to the screening of key ABCs and provides foundations for further investigation into the function of PdABCs and the creation of novel antifungal drugs to combat citrus green mold.