A Single Transcription Factor (PDD1) Determines Development and Yield of Winter Mushroom ( Flammulina velutipes )

Abstract

Most of the edible mushrooms cannot be cultivated or have low yield under industrial conditions, partially due to the lack of knowledge on how basidioma (fruiting body) development is regulated. From winter mushroom (Flammulina velutipes), one of the most popular industrially cultivated mushrooms, a transcription factor, PDD1, with a high-mobility group (HMG)-box domain was identified based on its increased transcription during basidioma development. pdd1 knockdown by RNA interference affected vegetative growth and dramatically impaired basidioma development. A strain with an 89.9% reduction in the level of pdd1 transcription failed to produce primordia, while overexpression of pdd1 promoted basidioma development. When the transcriptional level of pdd1 was increased to 5 times the base level, the mushroom cultivation time was shortened by 9.8% and the yield was increased by at least 33%. RNA sequencing (RNA-seq) analysis revealed that pdd1 knockdown downregulated 331 genes and upregulated 463 genes. PDD1 positively regulated several genes related to fruiting, including 6 pheromone receptor-encoding genes, 3 jacalin-related lectin-encoding genes, FVFD16, and 2 FVFD16 homolog-encoding genes. PDD1 is a novel transcription factor with regulatory function in basidioma development found in industrially cultivated mushrooms. Since its orthologs are widely present in fungal species of the Basidiomycota phylum, PDD1 might have important application prospects in mushroom breeding. IMPORTANCE Mushrooms are sources of food and medicine and provide abundant nutrients and bioactive compounds. However, most of the edible mushrooms cannot be cultivated commercially due to the limited understanding of basidioma development. From winter mushroom (Flammulina velutipes; also known as Enokitake), one of the most commonly cultivated mushrooms, we identified a novel transcription factor, PDD1, positively regulating basidioma development. PDD1 increases expression during basidioma development. Artificially increasing its expression promoted basidioma formation and dramatically increased mushroom yield, while reducing its expression dramatically impaired its development. In its PDD1 overexpression mutants, mushroom number, height, yield, and biological efficiency were significantly increased. PDD1 regulates the expression of some genes that are important in or related to basidioma development. PDD1 is the first identified transcription factor with defined functions in mushroom development among commercially cultivated mushroom species, and it might be useful in mushroom breeding.

A WD40 Protein Encoding Gene Fvcpc2 Positively Regulates Mushroom Development and Yield in Flammulina velutipes

“…The binary vector pBHg-BCA1 containing the resistance gene of hygromycin was used in the construction of the Fvcpc2 overexpression plasmid and RNAi plasmid as previously described (Wu et al, 2019). The promoter of glyceraldehyde-3-phosphate dehydrogenase Pgpd and terminator of trpC (TtrpC) were used to control the expression of Fvcpc2 or the sense and antisense sequence of Fvcpc2 in both plasmids (Kuo et al, 2004;Sekiya et al, 2013;Kim et al, 2015).…”

“…Plasmids Fvcpc2-OE and Fvcpc2-RNAi were transformed into F. velutipes dikaryotic strain F19 by the A. tumefaciensmediated transformation method (Wu et al, 2019), respectively. The positive transformants were detected by PCR with primers Pgpd-detect-F and TtrpC-detect-R.…”

“…The fruiting body was produced on the composted sawdust substrate (Wu et al, 2019). In order to mimic the industrial production of Winter Mushroom, the parts of fruiting bodies out of the vessel were harvested and the fresh weight was used to record the yield of each vessel.…”

“…To understand the function of Fvcpc2 in F. velutipes, the Fvcpc2 overexpression vector Fvcpc2-OE and the Fvcpc2 knockdown vector Fvcpc2-RNAi were constructed, respectively. The binary vector pBHg-BCA1, the promoter of glyceraldehyde-3-phosphate dehydrogenase (Pgpd) (Kuo et al, 2004) and the terminator of trpC (TtrpC) (Sekiya et al, 2013;Kim et al, 2015) were used to construct these plasmids as previously described (Wu et al, 2019).…”

Analysis of Reference Genes stability and Histidine Kinase Expression under Cold Stress in Cordyceps militaris

“…The fruiting body formation of various mushrooms depends on low temperature (cold stress) induction. For example, the fruiting body development was induced by shifting the cultivation condition (25 °C for mycelia) to lower temperature (15 °C) in Flammulina velutipes [12]. In Pleurotus ostreatus the mycelia were cultured at 20 °C for 30 days in a sawdust-medium, and then the temperature was lowered to 15 °C to induce fruit body development [13].…”