Phosphorus absorption and utilization in the transcription factor PaPho and the filamentous fungus Podospora anserina

Abstract:

As one of the essential nutrients of living organisms, phosphorus plays a key role in substance metabolism, signal transduction, and energy storage. [Objective] To explore the role of transcription factors related to phosphate metabolism in the filamentous fungus Podospora anserina and further study the regulatory mechanism of phosphorus uptake in eukaryotic microorganisms.[Methods] Two phosphorus-metabolization-related transcription factors PaPho1 and PaPho2 in P. anserina were knocked out by homologous recombination, and a double mutant ΔPaPho1ΔPaPho2 was constructed by genetic hybridization. The changes in mutant strains were analyzed by phenotypic analysis, inorganic phosphorus content determination, and acid phosphatase activity determination. The expression of phosphorous metabolism-related genes was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). [Results] The double mutant ΔPaPho1ΔPaPho2 could not grow in the medium with inorganic phosphate as the only source of phosphorus. There was no significant difference in the growth of ΔPaPho1ΔPaPho2and the wild-type strain in the medium with organic phosphate. In the medium supplemented with organic and inorganic phosphates, the inorganic phosphate content and acid phosphatase activity of ΔPaPho1ΔPaPho2were decreased by 25.0% and 61.9%, respectively, as compared with the wild-type strain. The expression level of inorganic phosphate transporter genes in ΔPaPho1ΔPaPho2 decreased significantly. [Conclusion] In P. anserine, PaPho1 and PaPho2, as transcription factors regulating phosphate metabolism signaling pathway, play a vital role in the absorption of inorganic phosphate, but they do not participate in the metabolic regulation of organic phosphate. This study provides references for the regulatory mechanism of the filamentous fungus P. anserine in the absorption of inorganic phosphate.

Key words:filamentous fungus;Podospora anserine;transcription factors;gene deletion;phosphorus metabolism;inorganic phosphate