Transcriptional profiling provides new insights into the role of nitric oxide in enhancing Ganoderma oregonense resistance to heat stress

Ganoderma is well known for its use in traditional Chinese medicine and is widely cultivated in China, Korea, and Japan. Increased temperatures associated with global warming are negatively influencing the growth and development of Ganoderma. Nitric oxide is reported to play an important role in alleviating fungal heat stress (HS). However, the transcriptional profiling of Ganoderma oregonense in response to HS, as well as the transcriptional response regulated by NO to cope with HS has not been reported. We used RNA-Seq technology to generate large-scale transcriptome data from G. oregonense mycelia subjected to HS (32 degrees C) and exposed to concentrations of exogenous NO. The results showed that heat shock proteins (HSPs), probable stress-induced proteins, and unigenes involved in D-amino-acid oxidase activityand oxidoreductase activitywere significantly up-regulated in G. oregonense subjected to HS (P < 0.05). The significantly up-regulated HSPs, monooxygenases, alcohol dehydrogenase, and FAD/NAD(P)-binding domain-containing proteins(P < 0.05) regulated by exogenous NO may play important roles in the enhanced HS tolerance of G. oregonense. These results provide insights into the transcriptional response of G. oregonense to HS and the mechanism by which NO enhances the HS tolerance of fungi at the gene expression level.