Functional Characterization of the GATA-Type Transcription Factor PaNsdD in the Filamentous Fungus Podospora anserina and Its Interplay with the Sterigmatocystin Pathway

Abstract

The model ascomycete Podospora anserina , featured by its strict sexual development, is a prolific but yet unexploited reservoir of natural products. The GATA-type transcription factor NsdD has been characterized by the role in balancing asexual and sexual reproduction, and governing secondary metabolism in filamentous fungi. In the present study, we functionally investigated the NsdD ortholog PaNsdD in P. anserina . Compared to the wild-type strain, vegetative growth, ageing processes, sexual reproduction, stress tolerance and interspecific confrontations in the mutant were drastically impaired, owing to the loss of function of PaNsdD. In addition, the production of 3-acetyl-4-methylpyrrole, a new metabolite identified in P. anserina in this study, was significantly inhibited in the ΔPaNsdD mutant. We also demonstrated the interplay of PaNsdD with the sterigmatocystin biosynthetic gene pathway, especially as the deletion of PaNsdD triggered the enhanced red-pink pigment biosynthesis that only occurs in the presence of the core polyketide synthase-encoding gene PaStcA of the sterigmatocystin pathway. Taken together, these results contribute to a better understanding of the global regulation mediated by PaNsdD in P. anserina , especially with regard to its unexpected involvement in fungal ageing process and its interplay with sterigmatocystin pathway. Importance Fungal transcription factors play an essential role in coordinating multiple physiological processes. Yet, little is known about the functional characterization of transcription factors in the filamentous fungus P. anserina . In this study, a GATA-type regulator PaNsdD was investigated in P. anserina . The results showed that PaNsdD was a key factor that can control the fungal ageing process, vegetative growth, pigmentation, stress response, interspecific confrontations, and positively regulate the production of 3-acetyl-4-methylpyrrole. Meanwhile, a molecular interaction was implied between PaNsdD and the sterigmatocystin pathway. Overall, loss of function of PaNsdD seems to be highly disadvantageous for P. anserina , which relies on pure sexual reproduction in limited lifespan. Therefore, PaNsdD is clearly indispensable for the survival and propagation of P. anserina in its complex ecological niches.

Genome-Wide Identification and Functional Analysis of the bZIP Transcription Factor Family in Rice Bakanae Disease Pathogen, Fusarium fujikuroi

“…In recent years, with the continuous improvement of genome databases, more and more TF families have been identified, such as bZIP [ 22 ], MYB [ 23 ], GATA [ 24 ], and PacC [ 25 ]. bZIP TFs are one of the most widely distributed and conserved proteins of eukaryotes.…”

Complementary Strategies to Unlock Biosynthesis Gene Clusters Encoding Secondary Metabolites in the Filamentous Fungus Podospora anserina

“…To counteract this thorny problem, some smart strategies have been developed in the past decade, based on targeted or global approaches. In previous work, we showed that targeted modification techniques could lead to the functional characterization of ST, a predominant metabolite in the filamentous fungal model P. anserina in liquid culture [ 50 , 51 ], but such an approach obviously limits access to larger metabolite exploitation. In this work, our main objective was to compare the global strategies usually used to deregulate SM gene clusters and illustrate the importance of complementary strategies as a foundation to activate silent BGCs and discover specific products of interest in the model fungus P. anserina .…”

“…However, to date, the metabolome diversity of this fungi is underexplored. A few sets of secondary metabolites have been isolated including anserinones A and B, two benzoquinones exhibiting antifungal, antibacterial, and cytotoxic activities [ 48 ], and sterigmatocystin (ST), a polyketide demonstrating larvicidal and antifungal activities [ 49 , 50 , 51 ]. To the best of our knowledge, apart from the ST gene cluster that has been experimentally confirmed and functionally characterized in P. anserina , only seven putative BGCs displaying lower sequence similarity might be assigned to known molecules, while none of the other clusters can be correlated to natural products [ 44 , 50 ].…”

Involvement of VIVID in white light‐responsive pigmentation, sexual development and sterigmatocystin biosynthesis in the filamentous fungus Podospora anserina

“…Vvd ( Pa_4_6960 ) gene sequence was identified by searching in the P. anserina genome database, using the N. crassa protein VVD (NCU03967) as a query (Espagne et al ., 2008). The Δ vvd mutant was constructed as previously described (Xie et al ., 2014; Shen et al ., 2022). In brief, a nourseothricin resistance cassette was used as the selection marker, which was amplified using primers 2F/3R from pBC‐nourseo plasmid.…”