Gene expression analysis for stem browning in the mushroom <i>Lentinula edodes</i>

The mushroom <i>Lentinula edodes,</i> is consumed worldwide and has high industrial value because of its rich content of bioactive compounds such as ergothioneine and eritadenine. Currently, mainstream artificial cultivation methods for this mushroom typically use synthetic logs. However, browning of the stem's interior (stem browning) has been observed during the cultivation in some <i>L. edodes</i> strains. Although browning does not affect the taste or other qualities of the mushroom, it gives consumers a perception of "poor quality", and is a major challenge for producers. To identify the genes responsible for stem browning in this mushroom, we performed differential gene expression analysis during stem browning development and quantified it using real-time PCR. Our results indicated that certain oxidoreductases, such as tyrosinase and laccase, were significantly upregulated during the progression of stem browning. The results obtained in the present study provide valuable insights to address the problem of stem browning in mushroom <i>L. edodes</i>.