Understanding the promotion of heat treatment on the flavor of Lentinula edodes using metabolomics integrated with transcriptomics.

The transcriptome and metabolome analyses revealed the differentially expressed metabolites (DEMs) and genes (DEGs) in the dried Lentinula edodes' response to heat treatment. Most DEMs between the L.edodes sample groups were lipids and lipid-like molecules, nucleosides, nucleotides, analogs, and organic acids and derivatives. DEMs enrich the pathway of the TCA cycle, alanine, aspartate, glutamate metabolism, and arginine biosynthesis. The proportion of DEGs annotation in the metabolism pathway and the number of DEGs increased within the drying process of 2 h. The DEGs were annotated in the signal transduction and amino acid metabolism pathways during the drying process of 2 h âˆ¼ 3 h. Five DEGs including LE01Gene04306, LE01Gene06275, LE01Gene11513, LE01Gene13848 and LE01Gene13853 existed in all comparative groups. Twenty-nine DEMs marker can be used for monitoring the quality of L.edodes during drying. The metabolic pathways, secondary metabolites biosynthesis, and unsaturated fatty acid biosynthesis were the landmark pathways that monitor DEMs and DEGs, and gamma-linolenic acid was a signal DEM marker. It provides new insights for understanding the flavor formation of L.edodes during the hot-air drying process.

The DnaJ Gene Family in Shiitake Culinary-Medicinal Mushroom, Lentinus edodes (Agaricomycetes): Comprehensive Identification, Characterization, and Expression Profiles under Different Conditions.

The DnaJ proteins, also called heat-shock protein 40 based on their molecular weight, play significant roles in organism growth and development and resistance to abiotic and biotic stresses. However, studies on the DnaJ gene family in Lentinus edodes (= Lentinula edodes) are less well known. In this study, 29 putative L. edode DnaJ genes (LeDnaJ01 to LeDnaJ29) were identified using bioinformatics analysis and were classified into four groups according to the presence of the J protein and zinc finger as well as C-terminal domain. Multiple cis elements related to the phytohormone and stresses were found in the promotor region of the LeDnaJ genes. In addition, qRT-PCR analysis revealed that 79.31% of LeDnaJ genes were induced by cadmium, 55.17% were induced by Trichoderma atroviride, and 37.93% were induced by heat stress, indicating that the LeDnaJ proteins might participate in the response of L. edodes to the multiple stresses. Meanwhile, qRT-PCR analysis also revealed that all LeDnaJs are expressed in at least one development stage, indicating that they could be involved in the process of L. edodes growth and development and the response to the abiotic and biotic stresses. Taken together, these results advance the functional analysis of DnaJ genes in Basidiomycetes.

The Reliability of DNA Sequences in Public Databases Belonging to the Most Economically Important Shiitake Culinary-Medicinal Mushroom Lentinus edodes (Agaricomycetes) in Asia.

Large numbers of DNA sequences deposited in the International Nucleotide Sequence Databases (INSD) are erroneously annotated. The erroneous information may lead to misleading conclusions or cause great economic losses to farmers. Lentinus edodes (= Lentinula edodes (Berk.) Pegler) is one of the most important and popular culinary-medicinal mushrooms with a high nutritional value. In this study, experimental and in silico methods were used to correct the sequences annotated as L. edodes in the INSD. A total of 3,426 nucleotide entries were retrieved from public databases, including 140 different types of genetic sequences. Excluding 1,893 genome sequences, the most abundant signatures represented by ITS (258) and IGS1 (259) sequences accounted for 33.23% of the total entries. A total of 3,058 sequences were annotated correctly, 350 were indeterminate, and 18 were annotated erroneously based on the two methods. Correction of sequences will be beneficial for species identification and annotation. Phylogenic analysis based on ITS sequences suggested that L. edodes segregate in four clades in the tree based on ITS sequences. The isolates from China were distributed into two clades. In L. edodes, the intraspecific variation of the ITS2 sequences was much higher than that of the ITS1 sequences. In addition, the genetic diversity of the L. edodes sequences from China was much higher than that of any other regions included in this study. The northwest and southwest regions of China were L. edodes diversity centers.

Detection of Quantitative Trait Loci Underlying Yield-Related Traits in Shiitake Culinary-Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

Increasing yield is a principal goal when breeding Lentinus edodes. The detection of quantitative trait loci (QTLs) underlying yield and its related traits, precocity and the number of fruiting bodies (NFs), is important in order to breed high-yield cultivars. Using composite interval mapping (CIM), we mapped a total of 25 QTLs responsible for precocity, NFs, and yield in 2 segregating populations of L. edodes. QTLs for the 3 traits were mapped on 5 different linkage groups, contributing 5.9% to 15.4% of the phenotypic variation. Colocated QTLs were also found underlying multiple traits, implying the presence of a genic pleiotropic effect or tightly linked genes. This is, to our knowledge, the first report of the genetic dissection of precocity, NFs, and yield using QTL mapping in L. edodes. Findings of this study will facilitate marker-assisted breeding of high-yield cultivars of L. edodes.

ITS1/5.8S/ITS2, a Good Marker for Initial Classification of Shiitake Culinary-Medicinal Lentinus edodes (Agaricomycetes) Strains in China.

China is home to rich wild and cultivated strains of Lentinus edodes, an important edible and medicinal mushroom. Artificial selection of L. edodes has a long history, and the widely cultivated strains belong to populations different from those of most wild strains. Internal transcribed spacer (ITS) regions have been used as good markers to identify L. edodes populations. But because ITS regions exhibit incomplete concerted evolution, the use of an ITS to identify L. edodes populations has been questioned. The objective of this study was to determine whether the ITS region is suitable for identifying L. edodes populations and which populations the widely cultivated strains and the most wild strains belong to by investigating intraindividual and differential ITS polymorphisms between 44 cultivars and 44 wild strains of L. edodes in China. Intraindividual ITS polymorphism is common in L. edodes strains, and most strains possessed 2 different ITS sequences, which came from their heterokaryons. The genetic polymorphisms of ITS1, 5.8S, and ITS2 in L. edodes strains are distinct. All strains were divided into one 5.8S type (5.8S-A), 2 ITS1 types (ITS1-A and ITS1-B), and 2 ITS2 types (ITS2-A and ITS2-B), which were subdivided into 2 branches (ITS2-A1 and ITS2-A2; ITS2-B1 and ITS2-B2). ITS1/5.8S/ITS2 could be used as a good marker in preliminary classification of L. edodes strains in China. It not only exhibited classified information of ITS1, 5.8S, and ITS2 for each strain at the same time, it also indicated whether the strain was heterozygous. The 44 cultivated strains were mainly the A/A/A1 type, and the 44 wild strains were mainly the A/A/A2 and other mixed types.

Expression and Antitumor Function of Latcripin-4 RCC1 and ANK Domain Protein on HepG2 from the Shiitake Medicinal Mushroom, Lentinus edodes C91-3 (Agaricomycetes), Transcriptome.

The recombinant protein of Latcripin-4 regulator of chromosome condensation 1 (RCC1) and ankyrin (ANK) domains were expressed and the antitumor activity of Latcripin-4 on HepG2 cells was studied. First, the Latcripin-4 transcript was selected from the medicinal mushroom Lentinus edodes C91-3 transcriptome by bioinformatics. Then the full-length gene of Latcripin-4 was isolated with 3'-full rapid amplification of cDNA ends (RACE) and 5'-full RACE methods according to the transcriptome. The RCC1 and ANK domains from the full-length gene were selected and inserted into the expression vector pET-32a (+) and expressed in Escherichia coli Rosetta-gami (DE3). Western blotting indicated that the protein was expressed successfully. The biological function of Latcripin-4 RCC1 and ANK domain protein on HepG2 cells was studied with the CCK-8 assay. All results demonstrated that Latcripin-4 RCC1 and ANK domain protein can inhibit the growth of human HepG2 liver cancer cells, which brings new insights to identifying antitumor proteins from medicinal food for cancer therapy.

Brown Mycelial Mat as an Essential Morphological Structure of the Shiitake Medicinal Mushroom Lentinus edodes (Agaricomycetes).

We show here, to our knowledge for the first time, that the brown mycelial mat of the xylotrophic shiitake medicinal mushroom, Lentinus edodes, not only performs a protective function owing to significant changes in the ultrastructure (thickening of the cell wall, increased density, and pigmentation of the fungal hyphae) but also is a metabolically active stage in the development of the mushroom. The cells of this morphological structure exhibit repeated activation of expression of the genes lcc4, tir, exp1, chi, and exg1, coding for laccase, tyrosinase, a specific transcription factor, chitinase, and glucanase, which are required for fungal growth and morphogenesis. This study revealed the maximum activity of functionally important proteins with phenol oxidase and lectin activities, and the emergence of additional laccases, tyrosinases, and lectins, which are typical of only this stage of morphogenesis and have a regulatory function in the development and formation of fruiting bodies.

Optimization of the Production of Extracellular Polysaccharide from the Shiitake Medicinal Mushroom Lentinus edodes (Agaricomycetes) Using Mutation and a Genetic Algorithm-Coupled Artificial Neural Network (GA-ANN).

Exopolysaccharide (EPS) production by a strain of Lentinus edodes was studied via the effects of treatments with ultraviolet (UV) irradiation and acridine orange. Furthermore, optimization of EPS production was studied using a genetic algorithm coupled with an artificial neural network in submerged fermentation. Exposure to irradiation and acridine orange resulted in improved EPS production (2.783 and 5.548 g/L, respectively) when compared with the wild strain (1.044 g/L), whereas optimization led to improved productivity (23.21 g/L). The EPS produced by various strains also demonstrated good DPPH scavenging activities of 45.40-88.90%, and also inhibited the growth of Escherichia coli and Klebsiella pneumoniae. This study shows that multistep optimization schemes involving physical-chemical mutation and media optimization can be an attractive strategy for improving the yield of bioactives from medicinal mushrooms. To the best of our knowledge, this report presents the first reference of a multistep approach to optimizing EPS production in L. edodes.

Lentiavidins: Novel avidin-like proteins with low isoelectric points from shiitake mushroom (Lentinula edodes).

A biotin-binding protein with a low isoelectric point (pI), which minimizes electrostatic non-specific binding to substances other than biotin, is potentially valuable. To obtain such a protein, we screened hundreds of mushrooms, and detected strong biotin-binding activity in the fruit bodies of Lentinula edodes, shiitake mushroom. Two cDNAs, each encoding a protein of 152 amino acids, termed lentiavidin 1 and lentiavidin 2 were cloned from L. edodes. The proteins shared sequence identities of 27%-49% with other biotin-binding proteins, and many residues that directly associate with biotin in streptavidin were conserved in lentiavidins. The pI values of lentiavidin 1 and lentiavidin 2 were 3.9 and 4.4, respectively; the former is the lowest pI of the known biotin-binding proteins. Lentiavidin 1 was expressed as a tetrameric protein with a molecular mass of 60 kDa in an insect cell-free expression system and showed biotin-binding activity. Lentiavidin 1, with its pI of 3.9, has a potential for broad applications as a novel biotin-binding protein.

Molecular characterization of shiitake medicinal mushroom, Lentinus edodes strains (higher Basidiomycetes) using RAPD and ITS sequencing.

The molecular phylogeny in seven strains of Lentinus edodes was studied based on RAPD and their internal transcribed spacers (ITS) regions. The strains were analyzed by RAPD with 20 arbitrary primers. Fifteen primers were found efficient for the amplification of the genomic DNA. The size of the polymorphic bands were in the range of 100-1000 bp. However, the size of ITS1-2 and ITS1-4 regions varied among the strains from 278 to 575 bp and from 410 to 616 bp, respectively. The higher alignment score of the ITS 1-2 region indicated more variability in the ITS 1-4 region. Thus, on the basis of RAPD-PCR and ITS sequencing it was found that strains LeC and LeI showed a high degree of divergence from all other strains.

A PCR method for the detection and differentiation of Lentinus edodes and Trametes versicolor in defined-mixed cultures used for wastewater treatment.

A PCR-based method for the quantitative detection of Lentinus edodes and Trametes versicolor, two ligninolytic fungi applied for wastewater treatment and bioremediation, was developed. Genomic DNA was used to optimize a PCR method targeting the conserved copper-binding sequence of laccase genes. The method allowed the quantitative detection and differentiation of these fungi in single and defined-mixed cultures after fractionation of the PCR products by electrophoresis in agarose gels. Amplified products of about 150 bp for L. edodes, and about 200 bp for T. versicolor were purified and cloned. The PCR method showed a linear detection response in the 1.0 microg-1 ng range. The same method was tested with genomic DNA from a third fungus (Phanerochaete chrysosporium), yielding a fragment of about 400 bp. Southern-blot and DNA sequence analysis indicated that a specific PCR product was amplified from each genome, and that these corresponded to sequences of laccase genes. This PCR protocol permits the detection and differentiation of three ligninolytic fungi by amplifying DNA fragments of different sizes using a single pair of primers, without further enzymatic restriction of the PCR products. This method has potential use in the monitoring, evaluation, and improvement of fungal cultures used in wastewater treatment processes.