Proteome and Transcriptome Reveal Involvement of Heat Shock Proteins and Indoleacetic Acid Metabolism Process in Lentinula Edodes Thermotolerance

Abstract

Background/Aims: Heat stress could cause huge losses for Lentinula edodes in China and other Asian cultivation areas. Yet our understanding of mechanism how to defend to heat stress is incomplete. Methods: Using heat-tolerant and heat-sensitive strains of L. edodes, we reported a combined proteome and transcriptome analysis of L. edodes response to 40 °C heat stress for 24 h. Meanwhile, the effect of LeDnaJ on the thermotolerance and IAA (indoleacetic acid) biosynthesis in L. edodes was analyzed via the over-expression method. Results: The proteome results revealed that HSPs (heat shock proteins) such as Hsp40 (DnaJ), Hsp70, Hsp90 and key enzymes involved in tryptophan and IAA metabolism process LeTrpE, LeTrpD, LeTam-1, LeYUCCA were more highly expressed in S606 than in YS3357, demonstrating that HSPs and tryptophan as well as IAA metabolism pathway should play an important role in thermotolerance. Over-expression of LeDnaJ gene in S606 strains showed better tolerance to heat stress. It was also documented that intracellular IAA accumulation of S606 (8-fold up) was more than YS3357 (2-fold up), and exogenous IAA enhanced L. edodes tolerance to heat stress. Conclusion: Our data support the interest of LeTrpE, LeDnaJ, tryptophan and IAA could play a pivotal role in enhancing organism thermotolerance.

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

“…In our study, the expression of hmhsp70 increased under heat shock indicating that hmhsp70 is involved in heat shock response in H. marmoreus. The result is consistent with the expression of Hsp70 genes in other mushrooms (Chen et al 2017;Wang et al 2018a;Zhang et al 2016;Zou et al 2018). The silencing of Hsp40 gene, LeDnaJ, in L. edodes defected its resistance to heat stress (Wang et al 2018b), while the over-expression of LeDnaJ gene in L. edodes S606 conferred the strain better tolerance to heat stress (Wang et al 2018a).…”

“…The result is consistent with the expression of Hsp70 genes in other mushrooms (Chen et al 2017;Wang et al 2018a;Zhang et al 2016;Zou et al 2018). The silencing of Hsp40 gene, LeDnaJ, in L. edodes defected its resistance to heat stress (Wang et al 2018b), while the over-expression of LeDnaJ gene in L. edodes S606 conferred the strain better tolerance to heat stress (Wang et al 2018a). Overexpression of an Hsp100 gene, PsHsp100, from Pleurotus sajor-caju complemented a thermotolerance defect in hsp104 mutant S. cerevisiae (Lee et al 2006).…”

“…Recently, some studies have related these proteins with heat stress resistance in edible mushrooms. The expression of hsp70 genes in Lentinula edodes and Pleurotus ostreatus were upregulated under heat stress (Fu et al 2016;Wang et al 2018a;Zou et al 2018), and the Hsp70s were more highly expressed in heat-tolerance strain than heat-sensitive strain. Even so, functional studies of hsp70 genes are quite limited in mushroom compared to yeast and filamentous fungi.…”

“…The expressed HSPs function as molecular chaperones in blocking protein aggregation, dissolving the denatured proteins and helping damaged proteins to fold. Wang et al reported that HSPs could regulate the IAA biosynthesis, and IAA accumulation could enhance thermotolerance of L. edodes (Wang et al 2018a). These studies demonstrated that the metabolic network of HSPs synthesis and functions under heat stress are complicated.…”

Hsp40 Protein LeDnaJ07 Enhances the Thermotolerance of Lentinula edodes and Regulates IAA Biosynthesis by Interacting LetrpE

“…LeDnaJ07 overexpression in L. edodes strain S606 enhanced the thermotolerance via regulating IAA biosynthesis, while LeDnaJ07 RNAi in L. edodes strain S606 played a negative role in regulating mycelial growth, the resistance to heat stress and T. atroviride and IAA biosynthesis after heat stress (Wang et al, 2018a,b). According to transcriptome and proteome analyses after heat stress, the protein level of LetrpE, a rate-limiting enzyme in the IAA biosynthesis pathway, in the thermotolerance strain S606 was increased by approximately 500-fold after heat stress, while its transcript level was obviously downregulated (Wang et al, 2018a). Further, LetrpE RNAi in S606 played a negative role in regulating L. edodes thermotolerance (Ma et al, 2018).…”