New Insights into Methyl Jasmonate Regulation of Triterpenoid Biosynthesis in Medicinal Fungal Species Sanghuangporusbaumii (Pilát) L.W. Zhou & Y.C. Dai

Abstract

Triterpenoids are secondary metabolites produced by the fungus Sanghuangporus baumii that have important pharmacological activities. However, the yield of triterpenoids is low and cannot meet market demand. Here, we treated S. baumii with several concentrations of MeJA (methyl jasmonate) and found that the total triterpenoid content was highest (23.31 mg/g) when the MeJA concentration was 250 μmol/L. qRT-PCR was used to quantify the transcription of five key genes involved in triterpenoid biosynthesis. The results showed that the relative transcription of most genes increased with increasing MeJA concentration, indicating that MeJA is a potent inducer of triterpenoid biosynthesis in S. baumii. To further explore whether other terpenoid biosynthesis pathways are also involved in the accumulation of triterpenoids induced by MeJA, we measured the contents of cis-Zeatin (cZ), gibberellins (GAs), and the transcript levels of related biosynthesis genes. We found that MeJA significantly inhibited the biosynthesis of cZ, GAs, and the transcription of related genes. The repressive effects of MeJA on cZ and GA accumulation were further confirmed by growth rate and biomass assays. In conclusion, our study provides an effective method to enhance the triterpenoid content of S. baumii, and also provides novel insights into the mechanism of MeJA-induced triterpenoid biosynthesis.

Research Progress of Bioactive Components in Sanghuangporus spp.

“…Species in Sanghuangporus have long been classified as Phellinus linteus , Phellinus baumii , Phellinus igniarius , or Inonotus linteus by many researchers from China and adjacent countries [ 6 , 7 , 15 , 16 , 17 , 19 , 30 , 40 , 53 , 60 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 ]. In 2021, Shen et al presented concrete proof for such misclassification in a study where they revised the ITS sequence in Genbank and clarified some taxonomical mistakes, such as redetermining I. baumii and I. vaninii as S. baumii and S. vaninii , respectively [ 80 ].…”

“…Sanghuangporus spp., also known as Phellinus or Inonotus in some of the literature and some areas worldwide, is a perennial genus of edible mushrooms widely distributed in boreal forests in East Asia, especially in subtropical and tropical areas, holding profound pharmaceutical potential [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. These medicinal mushrooms, as illustrated in Figure 1 , have been popular in oral use since ancient times in countries such as China, Korea, and Japan [ 4 , 5 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. The first mention could date back to approximately 2000 years ago, as the name ‘Sanger’ appeared in Shen Nong’s Materia Medica for treating gynecologic tumors taking the forms of abdominal lumps [ 2 , 20 , 21 , 22 , 23 ].…”

“…Mycelia, conversely, demonstrate higher levels of polysaccharides, proteins, and other bioactive content than the fruiting bodies [ 15 , 50 ]. The compounds in these two parts provide Sanghuang with many valuable functions, including antitumor activities and free-radical scavenging abilities [ 6 , 9 , 13 , 16 , 20 , 25 , 26 , 28 , 35 , 37 , 51 , 52 , 53 , 54 ]. Polysaccharides are reported to be the major medical component and possess anti-inflammatory, antioxidative, antitumor, diabetes-ameliorating, sleep-improving, and neuroprotective effects, often demonstrated through pathway regulation, free-radical scavenging, and metabolic regulation [ 3 , 10 , 15 , 32 , 34 , 50 , 55 , 56 , 57 , 58 , 59 ].…”

The AMP-Activated Protein Kinase (AMPK) Positively Regulates Lysine Biosynthesis Induced by Citric Acid in Flammulina filiformis

“…Existing studies tend to focus on enhancing biosynthetic capacity through genetic engineering, which invariably requires a great deal of time and effort and is hard to introduce into large-scale factory production. The mode of modern factory production of edible fungi provides a standardized model for growth regulation, which allows the adjustment of process parameters [ 10 , 11 ]. Regulating cultivation parameters to further increase lysine content during the production process is an important way to improve the quality of F. filiformis .…”

Effects on the Synthesis and Accumulation of Triterpenes in Leaves of Cyclocarya paliurus under MeJA Treatment

“…Liu et al treated Sanghuangporus baumii with several concentrations of MeJA. The accumulation of triterpenoids and expression of key genes involved in triterpenoid biosynthesis increased with increasing MeJA concentration, while the biosynthesis of other terpenoids was inhibited [11]. Key genes [3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and squalene epoxidase (SE)] and transcription factors [basic Helix-loop-helix (bHLH), MYB, and GRAS] involved in protostane triterpene biosynthesis in Alisma orientale were significantly enriched in a MeJAtreated group [12].…”