Cross Talk between Nitric Oxide and Calcium-Calmodulin Regulates Ganoderic Acid Biosynthesis in Ganoderma lucidum under Heat Stress

Abstract

We previously reported that high temperature impacts ganoderic acid (GA) biosynthesis in () via Ca Therefore, to further understand the signal regulating network of the organism's response to heat stress (HS), we examined the role of nitric oxide (NO) under HS. After HS treatment, the NO level was significantly increased by 120% compared with that under the control conditions. The application of a NO scavenger resulted in a 25% increase in GA compared with that found in the sample treated only with HS. Additionally, application of a NO donor to increase NO resulted in a 30% lower GA content than that in the sample treated only with HS. These results show that the increase in NO alleviates HS-induced GA accumulation. Subsequently, we aimed to detect the effects of the interaction between NO and Ca on GA biosynthesis under HS in Our pharmacological approaches revealed that the NO and Ca signals promoted each other in response to HS. We further constructed the silenced strain of nitrate reductase (NR) and calmodulin (CaM), and the results are in good agreement with the silenced strain and pharmacological experiment. The cross-promotion between NO and Ca signals is involved in the regulation of HS-induced GA biosynthesis in , and this finding is supported by studies with NRi and CaMi strains. However, Ca may have a more direct and significant effects on the HS-induced GA increase than NO. These data indicate that NO functions in signaling and has a close relationship with Ca in HS-induced GA biosynthesis. HS is an important environmental stress affecting the growth and development of organisms. We previously reported that HS modulates GA biosynthesis in via Ca However, the signal regulating network of the organism's response to HS has not yet been elucidated. In this study, we found that NO relieved HS-induced GA accumulation, and NO and Ca could exert promoting effects on each other in response to HS. Further research on the effect of NO and Ca on the production of GAs in response to HS indicated that Ca has a notably more direct and significant effect on the HS-induced GA increase than NO. Our results improve our understanding of the mechanism of HS signal transduction in fungi. A greater understanding of the regulation of secondary metabolism in response to environmental stimuli will provide clues regarding the role of these products in fungal biology.

Dual sgRNA‐directed gene deletion in basidiomycete Ganoderma lucidum using the CRISPR/Cas9 system

“…Genetic transformation systems, including Agrobacterium tumefacien ‐mediated and polyethylene glycol (PEG)‐mediated transformations, have been developed in G. lucidum (Shi et al , ; Xu et al , ; Xu and Zhong, ) and have been successfully used to enhance the production of bioactive compounds, such as ganoderic acids and polysaccharides (Zhou et al , ; Li et al , ; Zhang et al , , ; Fei et al , ; Xu et al , ). Gene silencing systems have also been used for the partial suppression of genes of interest in G. lucidum (Mu et al , ; Liu et al , ; Zhu et al , ). So far, however, targeted gene deletion has not been established in Ganoderma , although it would be a powerful tool for G. lucidum research in the post‐genomic era.…”

Dual functions of AreA, a GATA transcription factor, on influencing ganoderic acid biosynthesis in Ganoderma lucidum

“…NR ‐silenced strains were previously constructed by Liu et al . (). The full‐length cDNA of NR was obtained using the primers listed in Table S1 and cloned into the pGPiE plasmid, which was previously constructed.…”

“…tuoliensis (Kong et al, 2012). Recently, Liu et al (2018b) revealed that GA biosynthesis could be influenced by NO induced by heat stress. For example, under heat stress, an increased NO level could alleviate HS-induced GA biosynthesis (Liu et al, 2018b).…”

“…NR gene was previously obtained and analysed in Liu et al . (). The cDNA of NR and AreA was cloned using the paired primers listed in Table S1 and ligated to the overexpression vector (pGI‐gpd) previously constructed.…”

“…To further study the function of NR in regulation of nitrate assimilation and NO production, NR-silenced strains and NR-overexpressed strains were used for the following studies. NR-silenced strains were previously constructed by Liu et al (2018b). The full-length cDNA of NR was obtained using the primers listed in Table S1 and cloned into the pGPiE plasmid, which was previously constructed.…”