Biological Characterization, Domestication, and the Molecular Basis of Iron Enrichment in a Wild Flammulina yunnanensis Strain
TL;DR
In this study, a wild strain Z68, isolated from Tibet, was identified as Flammulina yunnanensis based on ITS sequence and phylogenetic analysis, providing insight for biological characterization, domestication, and the molecular basis of iron enrichment in a F. yunnanensis Z68.
Abstract
In this paper, we reported a wild strain Z68, isolated from Tibet, was identified as Flammulina yunnanensis based on ITS sequence and phylogenetic analysis. Optimal condition for its mycelial growth (maltose, yeast extract, magnesium sulfate, 20 °C and pH 7.0–8.0) and fruiting ability was confirmed. Its fruiting bodies contained 25.1 g/100 g protein and 19.80 g/100 g of 16 amino acids, with iron, potassium and zinc, contents significantly higher than these in the controls F. fennae and F. velutipes. Significantly, whole-genome sequencing and comparative analysis of iron-metabolism gene families were performed between F. yunnanensis, F. fennae and F. velutipes to elucidate the basis of its notably elevated iron content, revealing most single copied and conserved iron-related gene families and two-fold expanded iron permease FTR1 in F. yunnanensi, which is the iron–sulfur cluster assembly protein family. Sequence, topology (DeepTMHMM), and structural-confidence (ColabFold/AlphaFold2) analyses of FTR1 identified six species-specified physicochemical substitutions, of which a charge reverse at the intracellular channel (Glu→Lys) and a polar-to-nonpolar change in the TM3 pore (Ser→Ala) were predicted to enhance iron transport efficiency. These suggested a possible two-tier mechanism underlying the elevated iron content of F. yunnanensis, combining gene-family expansion and predicted functional fine-tuning of the FTR1 permease. This study provided insight for biological characterization, domestication, and the molecular basis of iron enrichment in a F. yunnanensis Z68.