A Comparative Proteome Approach Reveals Metabolic Changes Associated with Flammulina velutipes Mycelia in Response to Cold and Light Stress.

In some industrial processes, cold and light stresses are recognized as two important environmental triggers for the transformation of mycelia into fruit-bodies via intermediate primordia in Flammulina velutipes cultivation. To gain insights into the mechanism of regulation of F. velutipes mycelia in response to cold and light stress, proteins expressed abundantly and characteristically at particular stress states were investigated by using the isobaric tags for the relative and absolute quantitation labeling technique. Among the 1046 nonredundant proteins identified with a high degree of confidence, 264 proteins, which were detected as differentially expressed proteins, were associated with 176 specific KEGG pathways. In-depth data analysis revealed that the regulatory network underlying the cold and light response mechanisms of F. velutipes mycelia was complex and multifaceted, as it included varied functions such as rapid energy supply, the biosynthesis of lysine, phenylalanine, tyrosine, and γ-aminobutyric acid, the calcium signal transduction process, dynein-dependent actin and microtubule cytoskeleton formation, autolysis, oxidative stress adaptation, pigment secretion, tissue and organ morphogenesis, and other interesting stress-related processes. Insights into the proteins might shed light on an intuitive understanding of the cold and light stress response mechanism underlying the fruiting processes of F. velutipes. Furthermore, the data might also provide further insights into the stress response mechanism of macro-fungi and valuable information for scientific improvement of some mushroom cultivation techniques in practice.

Compositional Differences of the Winter Culinary-Medicinal Mushroom, Flammulina velutipes (Agaricomycetes), under Three Types of Light Conditions.

The focus of this study was to investigate the effect of light on the cultivation and the amounts of bio-active components in Flammulina velutipes. The mushrooms were cultivated under fluorescent tube (T8) grow lights, lightemitting diodes (LEDs), and cold-cathode fluorescent lamps. The biological efficiency of the T8 lights was the highest, at 92%. The crude fat content, crude fiber content, polysaccharide content, and ergosterol content were highest under the LEDs, at 2.9 g/100 g, 7.9 g/100 g, 3.9 g/100 g, and 1.4 mg/g, respectively. Moreover, vitamin D2 (1.9 µg/g) was generated only under light from LEDs. Principal component analysis showed that F. velutipes cultivated under the 3 different lighting conditions showed different profiles for proximate composition, nutritional compounds, and principal fatty acids.