Transcription Factor PdTP1 Regulates the Biotransformation of Limonene to α-Terpineol and the Growth of <i>Penicillium digitatum</i>

α-Terpineol, an alcoholic monoterpene with lilac-like aroma, possesses diverse biological activities and has found applications in the food, pharmaceutical, cosmetic, and agricultural industries. Our previous studies indicated that gene <i>PdTP1</i> was highly expressed in <i>Penicillium digitatum</i> DSM 62840 during the biotransformation of limonene to α-terpineol, while its actual biological functions are not fully understood. Here, <i>PdTP1</i> was functionally characterized with bioinformatics analysis, subcellular localization, transcriptional activation activity, overexpression, and RNA interference (RNAi) silencing and RNA-seq analysis. Results showed that PdTP1 protein contained a GAL₄-like Zn₂Cys₆ DNA-binding domain and a fungal_trans domain, was located in the nucleus and cell membrane and presented transcriptional activation effect, suggesting that <i>PdTP1</i> encoded a Zn₂Cys₆ type transcription factor. Overexpression of <i>PdTP1</i> in <i>P. digitatum</i> promoted limonene biotransformation and increased α-terpineol production, and opposite results were observed after the silencing of <i>PdTP1</i>. Moreover, transcription factor PdTP1 was found to affect the growth of <i>P. digitatum</i> and participate in ionic stress and oxidative stress responses. RNA-seq data revealed that altering the <i>PdTP1</i> expression influenced the expression of some genes related to terpene metabolism or biosynthesis, fungal growth, and stress responses. In summary, <i>PdTP1</i>, which encoded a Zn₂Cys₆ transcription factor, played important roles in improving the production of α-terpineol from limonene and regulating fungal growth and environmental stress responses.