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Pleurotus ostreatus is a popular edible mushroom cultivated worldwide. However, the mechanism of P. ostreatus primordia formation is unclear. Pofst3 is a MHR superfamily transcription factor, which has the function of regulating primordia formation. In this study, the target genes of Pofst3 in P. ostreatus were identified by DAP-Seq approach at the genome level, 1481 peaks were obtained and the Pofst3 binding motif sequence was GARGRVGARGAR. The interaction between transcription factor Pofst3 and this motif was confirmed in vitro and in vivo through electrophoretic mobility shift (EMSA) and yeast one-hybrid screening (Y1H) assays. Among the top 20 GO enrichment results, most were related to transcriptional regulation, and some transcription factor encoding genes, such as HMG-box (gene_5346), MADS-box (gene_86), FOG (gene_6211) and RFX (gene_3496) were obtained. Besides basic metabolism, MAPK signaling pathway, Inositol phosphate metabolism, Glycosylphosphatidylinositol (GPI)-anchor biosynthesis and Pentose phosphate pathway were significantly enriched in the KEGG pathway analysis. The expression levels of randomly selected 11 genes, some transcription factor genes, and genes involved in metabolic pathways in wild and Pofst3 transgenic P. ostreatus strains indicated that target genes likely involved in the development of the P. ostreatus primordia. These results indicated that transcription factor Pofst3 ultimately negatively regulated the development of P. ostreatus primordia very likely through regulating a series of biological pathways. • In this study, genes potentially regulated by transcription factor Pofst3 in P. ostreatus were identified by DAP-Seq approach at the genome level. • We identified the cis binding element of transcription factor Pofst3, and found Pofst3 regulated Pleurotus ostreatus development by targeting multiple biological pathways. • This was also a rare report on using DAP method to screen transcription factor target genes in edible mushrooms. [ABSTRACT FROM AUTHOR]

Pleurotus ostreatus (Jacq.) P. Kumm is the second most cultivated edible mushroom worldwide. Temperature is one of the main environmental factors affecting the growth and fructification of mushrooms. However, the effects of ambient temperature on the growth, development, and production of bag-cultured P. ostreatus are still unclear. In this study, eight ambient temperatures (15 °C, 18 °C, 20 °C, 22 °C, 25 °C, 28 °C, 30 °C, and 32 °C) were used to cultivate P. ostreatus mycelia with cottonseed hull as substrate. Then, the agronomic traits and the activities of substrate-degrading and antioxidant enzymes were determined. The mycelial growth and fructification of P. ostreatus differed significantly under different temperatures, and 22 °C was the optimum temperature for mycelial culture when we comprehensively analyzed all the agronomic traits. The mycelial growth rate and the biological efficiency under 22 °C were 0.56 cm/d and 99.53%, respectively. Furthermore, there were also significant differences in the activities of substrate-degrading enzymes and antioxidant enzymes under different ambient temperatures. The highest activities of lignocellulose-degrading enzymes (laccase, xylanase, and cellulase), amylase, and proteinase at the vegetative growth stage occurred at 15–22 °C, 20–22 °C, and 22–30 °C, respectively. The highest activities of superoxide dismutase, peroxidase, and catalase at the vegetative growth stage occurred at 28–30 °C. This study provides a reference temperature for bag-cultured P. ostreatus. [ABSTRACT FROM AUTHOR]

The 1-aminocyclopropane-1-carboxylic acid (ACC) pathway that synthesizes ethylene is shared in seed plants, fungi and probably other organisms. However, the evolutionary relationship of the key enzyme ACC oxidase (ACO) in the pathway among organisms remains unknown. Herein, we cloned, expressed and characterized five ACOs from the straw mushroom (Volvariella volvacea) and the oyster mushroom (Pleurotus ostreatus): VvACO1-4 and PoACO. The five mushroom ACOs and the previously identified AbACO of the button mushroom contained all three conserved residues that bound to Fe(II) in plant ACOs. They also had variable residues that were conserved and bound to ascorbate and bicarbonate in plant ACOs and harbored only 1–2 of the five conserved ACO motifs in plant ACOs. Particularly, VvACO2 and AbACO had only one ACO motif 2. Additionally, VvACO4 shared 44.23% sequence identity with the cyanobacterium Hapalosiphon putative functional ACO. Phylogenetic analysis showed that the functional ACOs of monocotyledonous and dicotyledonous plants co-occurred in Type I, Type II and Type III, while putative functional gymnosperm ACOs also appeared in Type III. The putative functional bacterial ACO, functional fungi and slime mold ACOs were clustered in ancestral Type IV. These results indicate that ACO motif 2, ACC and Fe(II) are essential for ACO activity. The ACOs of the other organisms may come from the horizontal transfer of fungal ACOs, which were found ordinarily in basidiomycetes. It is mostly the first case for the horizontal gene transfers from fungi to seed plants. The horizontal transfer of ACOs from fungi to plants probably facilitates the fungal-plant symbioses, plant–land colonization and further evolution to form seeds. [ABSTRACT FROM AUTHOR]

Abstract Only a few transcription factors involved in mushroom development have been reported till now, Therefore, identification of transcription factors in common edible mushroom has commercial and scientific importance. In this study, the Pofst3 gene from Pleurotus ostreatus was cloned and characterized. Bioinformatics analysis showed that Pofst3 protein had 71% sequence similarity with fst3 of model mushroom Schizophyllum commune. Furthermore, the function of Pofst3 gene was analyzed by overexpression and antisense silencing in P. ostreatus via Agrobacterium -mediated transformation. Expression verification of Pofst3 in transformants through qRT-PCR showed that compared with the wild type strains, the transcription level was about 1.26 ∼ 9.59 and 0.01 ∼ 0.30 fold in Pofst3 overexpressing and silencing strains, respectively. Petri dish and bag cultivation tests of transgenic strains showed that the number of primordia and the type of fruiting bodies of Pofst3 overexpressing strains were consistent with the wild type strains, i.e. fewer primordia and larger fruiting bodies; the number of primordia formed by Pofst3 silencing strains were more than those of wild type strains, but fruiting bodies were smaller. It was very likely that Pofst3 was involved in the regulation of P. ostreatus development through inhibiting the formation of clusters of primordia. [ABSTRACT FROM AUTHOR]