Heat stress-induced reactive oxygen species participate in the regulation of HSP expression, hyphal branching and ganoderic acid biosynthesis in Ganoderma lucidum

Abstract

Heat stress (HS) is an important environmental factor that affects the growth and metabolism of edible fungi, but the molecular mechanism of the heat stress response (HSR) remains unclear. We previously reported that HS treatment increased the length between two hyphal branches and induced the accumulation of ganoderic acid biosynthesis and the gene expression of heat shock proteins (HSPs) in Ganoderma lucidum. In this study, we found that HS induced a significant increase in the cytosolic ROS concentration, and exogenously added ROS scavengers NAC, VC and NADPH oxidase (Nox) inhibitor DPI reduce the cytosolic ROS accumulation in G. lucidum. In addition, the phenomena of the increased gene expression and increased length between the two hyphal branches and the accumulation of GA biosynthesis induced by HS were mitigated. Furthermore, we investigated the effects of HS on Nox-silenced strains (NoxABi-10, NoxABi-11 and NoxRi-4, NoxRi-7) and found that the level of ROS concentration was lower than that in wild-type (WT) strains treated with HS. Additionally, Nox silenced strains reduced the HS-induced increase in HSP expression, the length between two hyphal branches and GA biosynthesis compared with the WT strain. These data indicate that HS-induced ROS participate in the regulation of HSP expression, hyphal branching and ganoderic acid biosynthesis in G. lucidum. In addition, these findings identified potential pathways linking ROS networks to HSR, physiological and metabolic processes in fungi and provide a valuable reference for studying the role of ROS in HSR, mycelium growth and secondary metabolites.

Metabolic Response of Pleurotus ostreatus to Continuous Heat Stress

“…Because of the antioxidant properties of glutathione, we confirmed the self-resistance of P. ostreatus to heat stress; the complete detailed mechanism of that resistance requires further study. As we known, heat stress can cause the outbreak of ROSs, and further damage to mycelia (Liu et al, 2018b;Lei et al, 2019), if we can apply the above-mentioned substances to regulate the level of redox when the mycelia may suffer from heat stress, it may be able to remove part of ROS, thus causing lower damage to the mycelia and stabilizing the bioactive components in the mycelia.…”

“…Kong et al (2012) discovered that nitric oxide (NO) can alleviate heat stress-induced oxidative damage in Pleurotus eryngii. Other signaling molecules similar to NO, such as calcium (Ca 2+ ), reactive oxygen species (ROS), and hydrogen sulfide (H 2 S), were found to participate in the heat stress response in G. lucidum (Zhang et al, 2016;Liu et al, 2018b;Tian et al, 2019). Finally, further studies have reported activated phospholipase D (PLD), a significant accumulation of phosphatidic acid (PA) (Liu et al, 2017a), and increased cell membrane fluidity upon heat stress (Liu et al, 2017b).…”

Heat shock protein 70 (HmHsp70) from Hypsizygus marmoreus confers thermotolerance to tobacco

“…Although, the heat shock response has been studied in considerable detail in yeast and plant (McAlister and Finkelstein 1980;Richter et al 2010;Song et al 2012), the mechanism of heat shock response in basidiomycetes remains elusive. Mushrooms evolved various strategies to response and alleviate heat shock stress, including HSPs synthesis, trehalose accumulation, and reactive oxygen species scavenging (Chen et al 2017;Liu et al 2016Liu et al , 2018Liu et al , 2019Wang et al 2017). In this study, we focused on a HSPs gene involved in heat shock response in H. marmoreus.…”

“…Cytosolic Ca 2+ participates in heat shock signal transduction and the increased intracellular calcium triggers the accumulation of HSPs ). Liu et al (2018) reported that heat stress induced a significant increase in the cytosolic reactive oxygen species concentration, which also participate in the regulation of HSP expression. The expressed HSPs function as molecular chaperones in blocking protein aggregation, dissolving the denatured proteins and helping damaged proteins to fold.…”

Integrated Proteomics and Metabolomics Analysis Provides Insights into Ganoderic Acid Biosynthesis in Response to Methyl Jasmonate in Ganoderma Lucidum

“…To date, methods to promote GA biosynthesis have been studied, and it has been proven that different carbon sources, nitrogen sources and initial pH have significant effects on GA biosynthesis [6,7]. The addition of some small molecular compounds to mycelium, such as phenobarbital [8], acetic acid [9], and salicylic acid [10], can also significantly improve the content of GAs in G. lucidum. Further studies have found that some signaling molecules, such as calcium, nitric oxide, reactive oxygen species (ROS), phospholipids, hydrogen sulfide are involved in the regulation of environment-induced GA biosynthesis [10][11][12][13][14][15].…”