AUTHOR=Han Pengjie , Hua Zhongyi , Zhao Yuyang , Huang Luqi , Yuan Yuan 

TITLE=PuCRZ1, an C2H2 transcription factor from Polyporus umbellatus, positively regulates mycelium response to osmotic stress

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1131605

DOI=10.3389/fmicb.2023.1131605

ISSN=1664-302X

ABSTRACT=<p><italic>Polyporus umbellatus</italic> is an edible and medicinal mushroom with the capacity to produce sclerotia. However, the mechanism of <italic>P. umbellatus</italic> sclerotia formation is unclear. CRZ1 is a C2H2 family transcription factor involved in the Ca<sup>2+</sup>-calcineurin signaling pathway, which has the function of regulating sclerotia formation, maintaining ion homeostasis, and responding to stress. In this study, we identified 28 C2H2 transcription factors in <italic>P. umbellatus</italic> genome, 13 of which are differentially expressed between mycelium and sclerotia, including <italic>PuCRZ1</italic>. Combining DNA affinity purification and sequencing (DAP-seq) and quantitative real-time PCR (qRT-PCR), three genes (<italic>PuG10</italic>, <italic>PuG11</italic>, <italic>PuG12</italic>) were identified as putative <italic>PuCRZ1</italic> target genes containing a putative binding motif (GTGGCG) within their promoter. Yeast single hybridization (Y1H) and EMSA further confirmed that <italic>PuCRZ1</italic> can bind to the promoter region of <italic>PuG10</italic>, <italic>PuG11</italic>, and <italic>PuG12</italic>. PuCRZ1 gene could reduce the sensitivity of NaCl in yeast cells. Furthermore, overexpression of the PuCRZ1 target gene, especially the FVLY domain containing gene <italic>PuG11</italic>, could improve the mycelia growth rate and mannitol tolerance in <italic>P. umbellatus</italic>. These results demonstrate that <italic>PuCRZ1</italic> in the Ca<sup>2+</sup>-calcineurin signaling pathway plays an important role in mycelia growth, as well as osmotic stress tolerance.</p>