Tissue cultivation conditions and transcriptome analysis of Tremella fuciformis primordia for industrial production purposes.

Direct acquisition of primordia represents a feasible approach for the industrial production of Tremella fuciformis fruit bodies, with stable tissue culture and multiplication of primordia being crucial steps. In this study, T. fuciformis primordia were successfully cultured and multiplied on artificial media. The effects of environmental and nutritional factors on primordia development and morphological transformation were systematically investigated. Scanning electron microscopy (SEM) was used to examine the microstructure of primordia and other morphological forms of T. fuciformis. Transcriptome analysis was conducted to identify gene expression differences between primordia, yeast-form cells, and mycelia. The results demonstrate that T. fuciformis primordia can be stably cultured and multiplied while retaining the ability to differentiate into fruiting bodies without the presence of Annulohypoxylon stygium. The optimal conditions for primordia growth were determined to be 22 °C and pH 6.0, with glucose and sucrose serving as the most effective carbon sources. Yeast extract and beef extract were found to be suitable nitrogen sources. Macromolecular carbon sources, mixed amino acids, and inorganic nitrogen sources promoted the conversion of primordia into mycelia. Under low-oxygen conditions, both primordia and mycelia readily transformed into yeast-form cells. Most differentially expressed genes between primordia, mycelia, and yeast-form cells were associated with carbon metabolism and amino acid metabolism. These findings provide valuable theoretical insights into the biological characteristics, cultivation techniques, and spawn production of T. fuciformis, and offer important directions for its industrialized production.