Tomohiro Suzuki

• Ph.D
• Professor (Associate) at Utsunomiya University

The formation of resting cysts is a strategy for survival in unfavorable environments by single cell organisms such as protists. Here, we show that Colpoda resting cysts have high salinity tolerance and investigate the changes in gene expression that underpin this effect. Colpoda resting cysts can tolerate saline conditions up to 3.5% NaCl. A compa...

Tulip mild mottle mosaic disease, caused by tulip mild mottle mosaic virus (TMMMV, species Ophiovirus tulipae), was first reported in Japan in 1979. TMMMV has a negative-sense ssRNA genome and is closely related to ophioviruses such as Mirafiori lettuce big vein virus (MLBVV, Ophiovirus mirafioriense). However, its complete nucleotide sequence has...

The mushroom Lentinula edodes, is consumed worldwide and has high industrial value because of its rich content of bioactive compounds such as ergothioneine and eritadenine. Currently, mainstream artificial cultivation methods for this mushroom typically use synthetic logs. However, browning of the stem’s interior (stem browning) has been observed d...

Edamame and chamame (brown edamame) are immature soybeans that contain abundant protein, vitamins, and dietary fiber. Edamame has a different nutrient composition compared with mature soybeans, as evidenced by its higher content of vitamins and folic acid. Recent studies have shown that proteins in mature soybeans, such as β-conglycinin, and dietar...

The green alga Pediastrum duplex forms colonies through asexual reproduction and has a unique life cycle. To elucidate the mechanisms that regulate the asexual reproductive cycle in P. duplex, we analyzed the effects of light on the processes and gene expression involved in each step of the asexual reproductive cycle, revealing light irradiation to...

Objective In 2004, after consuming angel-wing mushrooms, Pleurocybella porrigens, 59 incidents of food poisoning were reported in Japan. Consequently, 17 individuals died of acute encephalopathy. In 2023, we proved that a lectin, pleurocybelline, and pleurocybellaziridine from this mushroom caused damage to the brains of mice. Although we reported...

Malformed flowers similar to super-double-flowers were observed in potted ‘Cherie’ carnation (Dianthus caryophyllus L.) plants. In the malformed flower (mlf) lines, most flowers were malformed at 15°C, but not at 20°C. Thus, we hypothesized that the malformation was due to a mutation associated with morphological responses to temperature. In this s...

α,α-trehalose is a well-known sugar that plays a key role in establishing tolerance to environmental stresses in many organisms, except unicellular eukaryotes. However, almost nothing is known about α,β-trehalose, including their synthesis, function, and even presence in living organisms. In this study, we identified α,β-trehalose in the resting cy...

Gladiolus (Gladiolus spp.) florets exhibit low ethylene sensitivity. Accordingly, the wilting of their tepals is an ethylene-independent process. Both trehalose and cycloheximide can extend the vase life of gladiolus florets. Floral senescence is probably regulated by programmed cell death. However, senescence-related genes have not been thoroughly...

This is a report of a complete genome sequence of bean common mosaic virus in Vietnam. This virus shares around 99% nucleotide identity with a Nepal isolate.

Protist species are distributed worldwide. The processes that enabled this global distribution are unclear. One possible means is through the oceanic dispersal of freshwater protists, although this has not been investigated in detail to date. Here, the ability of resting cysts to tolerate saline conditions is examined as a possible mechanism that e...

Resting cyst formation is a crucial process of cryptobiosis in protists. In colpodid ciliates, cyst formation is accompanied by large-scale morphological changes such as changes of cell shape, resorption of cilia, and formation of a cyst wall; additionally, the cell cycle is arrested. These changes provide acquired tolerance against environmental s...

The interactions between the host immune system and intestinal microorganisms have been studied in many animals, including fish. However, a detailed analysis has not been performed in medaka, an established fish model for biological studies. Here, we investigated the effect of immunodeficiency on the microbiota composition and the effect of gut bac...

The remarkable mechanical strength and extensibility of spider dragline silk spidroins are attributed to the major ampullate silk proteins (MaSp). Although fragmented MaSp molecules have been extensively produced in various heterologous expression platforms for biotechnological applications, complete MaSp molecules are required to achieve instincti...

Decay process of wood of Japanese white birch [ Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara] tree by Inonotus obliquus (Fr.) Pilát was clarified by using the regression model in wood color and chemical components as a function of height position (1, 2, 3, and 4 m above the ground), wood type (sound wood and decayed wood), and their int...

Inonotus obliquus is a pathogenic fungus found in living trees and has been widely used as a traditional medicine for cancer therapy. Although lignocellulose-degrading enzymes are involved in the early stages of host infection, the parasitic life cycle of this fungus has not been fully understood. In this study, we aimed to investigate the activiti...

Lentinula edodes (shiitake mushroom) is one of the most widely cultivated edible mushrooms and is primarily cultivated using sawdust medium. While there have been improvements in the cultivation technology, the mechanism of mycelial block cultivation, such as mycelial growth and enzymatic sawdust degradation, has not been clarified. In this study,...

Ascomycete lectins may play an important role in their life cycle. In this report, we mined a ricin B-type lectin, named CmRlec, from the Cordyceps militaris genome by homology search. Furthermore, we succeeded in the soluble expression of CmRlec using β-glucuronidase as a solubilization tag and demonstrated that this lectin is a novel chitin-recog...

Mitochondria play an essential role in intracellular energy metabolism. This study described the involvement of Bombyx mori nucleopolyhedrovirus (BmNPV) GP37 (BmGP37) in host mitochondria. Herein, the proteins associated with host mitochondria isolated from BmNPV-infected or mock-infected cells by two-dimensional gel electrophoresis were compared....

Fairy chemicals (FCs), 2-azahypoxanthine (AHX), imidazole-4-carboxamide (ICA), and 2-aza-8-oxohypoxanthine (AOH), are molecules with many diverse functions in plants. The defined biosynthetic pathway for FCs is a novel purine metabolism in which they are biosynthesized from 5-aminoimidazole-4-carboxamide. Here, we show that one of the purine salvag...

2-Azahypoxanthine was isolated from the fairy ring-forming fungus Lepista sordida as a fairy ring-inducing compound. 2-Azahypoxanthine has an unprecedented 1,2,3-triazine moiety, and its biosynthetic pathway is unknown. The biosynthetic genes for 2-azahypoxanthine formation in L. sordida were predicted by a differential gene expression analysis usi...

The sapwood of Japanese cedar (Cryptomeria japonica D. Don) was decayed by the brown-rot fungus Fomitopsis palustris under bright and dark conditions. Scanning electron microscopy revealed the presence of mycelia inside the wood even after 1 week from the start of fungal exposure. Moreover, holes were observed in the torus after fungal exposure. Ru...

2-Azahypoxanthine (AHX) and 2-aza-8-oxohypoxanthine (AOH), discovered as causal substances of fairy rings, are known to be endogenous in the fairy ring-forming Lepista sordida. In this study, we showed that xanthine dioxygenase, an a-ketoglutarate-dependent dioxygenase, might catalyze the conversion of AHX to AOH in the fungus. Furthermore, this en...

In Japan in 2004, 59 people who had consumed angel-wing mushroom, Pleurocybella porrigens, experienced acute encephalopathy, and of these 17 died. We purified a lethal protein to mice, pleurocybelline (PC), from P. porrigens. Although PC caused no damage to the brain, PC formed a complex with a lectin (PPL) and showed exo-protease activity, degradi...

Lentinula edodes (shiitake mushroom) is one of the most widely cultivated edible mushrooms and is primarily cultivated using sawdust medium. While there have been improvements in the cultivation technology, the mechanism of mycelial block cultivation, such as mycelial growth and enzymatic sawdust degradation, has not been clarified. In this study,...

Four types of biodegradable plastics were evaluated for their biodegradability in seawater collected at Ajigaura coast, Japan, in the presence or absence of marine sand. One of the plastics, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), showed a degree of biodegradation in a seawater sample, and the addition of marine sand markedly accelera...

Hermansky-Pudlak syndrome is an autosomal recessive disease characterized by albinism, visual impairment, and blood platelet dysfunction. One of the genes responsible for Hermansky-Pudlak syndrome, hps1, regulates organelle biogenesis and thus plays important roles in melanin production, blood clotting, and the other organelle-related functions in...

Fungi belonging to the Ascomycete genus Cordyceps are endoparasitoids and parasites, mainly of insects and other arthropods. Cordyceps militaris has been used as a therapeutic drug for cancer patients. However, the infection, parasitism, and fruiting body formation mechanisms of this fungus are still unknown. Based on our hypothesis that lectin(s)...

Lepista sordida is a fairy ring-forming fungus that belongs to the family Tricholomataceae and is widely distributed in the Northern Hemisphere. Here, we report the complete mitochondrial genome sequence of L. sordida. The mitochondrial genome (57,375 bp) contained 20 protein-coding genes, 2 ribosomal RNA genes, and 26 transfer RNA genes. Phylogene...

2-Azahypoxanthine (AHX) was first isolated from the culture broth of the fungus Lepista sordida as a fairy ring-inducing compound. It has since been found that a large number of plants and mushrooms produce AHX endogenously and that AHX has beneficial effects on plant growth. The AHX molecule has an unusual, nitrogen-rich 1,2,3-triazine moiety of u...

RNA-seq data analysis of cigarette beetle (Lasioderma serricorne) strains having different sensitivities to pyrethroids identified sodium channel mutations in strains showing pyrethroid resistance: the T929I and F1534S mutations. These results suggest that reduced sensitivity of the sodium channel confers the pyrethroid resistance of L. serricorne....

Lotus root (Nelumbo nucifera) is an edible rhizome that the consumption/production has continuously increased as more consumers demand convenient and ready-to-eat foods. However, the processing, storage, and transportation of fresh-cut fruits and vegetables promotes physiological deterioration, such as browning, which leads to a reduction in the va...

Here, we report the draft genome sequence of the white-rot basidiomycete fungus Phanerochaete sordida YK-624 (ATCC 90872), which was isolated in Yakushima, Kagoshima, Japan. The genome of this strain was found to be 41.2 Mbp, with a G+C content of 58.7%, and to comprise 17,108 predicted protein-coding sequences.

Inonotus obliquus is pathogenic fungus on living trees and has been widely used as a traditional medicine for cancer therapy. Although it has been reported that lignocellulose-degrading enzymes are involved in the early stage of host infection, the parasitic life cycle of this fungus has not been fully clarified. In the present study, we investigat...

Dahlia is a major ornamental plant that is cultivated worldwide. However, dahlia plants, which are mainly propagated through vegetative reproduction, are susceptible to widespread damage by viruses, and viral control requires that the nature of the infecting virus(es) be known. In this study, dahlia common mosaic virus (DCMV) was detected for the f...

Plant diseases caused by the Cercospora genus of ascomycete fungi are a major concern for commercial agricultural practices. Several Cercospora species can affect soybeans, such as C. kikuchii which causes soybean leaf blight. Speciation in Cercospora on soybean has not been adequately studied. Some cryptic groups of Cercospora also cause diseases...

Biocontrol fluorescent pseudomonads produce a number of antibiotic organic compounds, including 2,4-diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, and phenazine. We previously classified rhizospheric fluorescent pseudomonads harboring antibiotic biosynthetic gene clusters into 10 operational taxonomic units (OTUs). In the present study, we repo...

Changes in the subcellular localisation of chloroplasts help optimise photosynthetic activity under different environmental conditions. In many plants, this movement is mediated by the blue-light photoreceptor phototropin. A model organism with simple phototropin signalling that allows clear observation of chloroplasts would facilitate the study of...

Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. It was demonstrated that YK-624 ca...

Lotus root ( Nelumbo nucifera ) is an edible rhizome that the consumption/production has continuously increased as more consumers demand convenient and ready-to-eat foods. However, the processing, storage, and transportation of fresh-cut fruits and vegetables promotes physiological deterioration, such as browning, which leads to a reduction in the...

In this study, we report a more efficient heterologous expression of lectin from Pleurocybella porrigens (PPL) using an Escherichia coli-based expression system. The yield (9.3 mg/L culture broth) of recombinant PPL (rPPL) using this expression system was increased approximately 9-fold compared to our previous study. The rPPL obtained in this study...

Mushroom-forming fungi produce unique bioactive compounds that have potential applications as medicines, supplements, and agrochemicals. Thus, it is necessary to clarify the biosynthetic pathways of these compounds using genome and transcriptome analyses. This review introduces some of our research on bioactive compounds isolated from mushrooms, as...

In Japan, tulip-growing areas have been plagued by viral diseases for decades, but the viruses causing the damage remain undescribed. In this study, Nicotiana benthamiana and Chenopodium quinoa plants mechanically inoculated with crude sap from a symptomatic tulip flower exhibited necrosis symptoms. Additionally, flexuous and filamentous virus part...

Cut astilbe (Astilbe × arendsii) inflorescences have many small florets with low ethylene sensitivity, and a short vase life. The senescence of flowers is complex and probably regulated by programmed cell death, but specific senescence-related genes have not been widely studied, apart from ethylene-sensitive species. In this study, we investigated...

Polyhydroxyalkanoate (PHA) is a biodegradable polymer that is synthesized by a wide range of microorganisms. One of the derivatives of PHA, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) has flexible material properties and low melting temperature. We have previously demonstrated that PHBH is degradable in a freshwater environment via the for...

Moisture content (MC) is an important factor in the freshness of shiitake mushrooms (Lentinula edodes). In this study, we developed a simple prediction method for MC of shiitake mushrooms using near-infrared (NIR) imaging at 1450 nm, as the band at 1450 nm is strongly correlated with OH groups. First, a NIR image was captured by an InGaAs sensor wi...

In the major eusocial species of Hymenoptera, the regulatory mechanisms controlling queen/worker differentiation and exclusive reproduction by queens have been studied extensively. These studies have shown that insulin/insulin‐like growth factors and juvenile hormones (JHs) act as key endocrine factors. However, although considerable knowledge has...

A strain-designated YsT was isolated as a filterable bacterial strain from Lake Sanaru, a brackish water lake in Hamamatsu Japan. YsT is aerobic, Gram-negative, and slender rod shaped. YsT grew optimally at 30 °C, pH 7.0–8.0 and without the addition of NaCl. MK-7 was the sole isoprenoid quinone. The main cellular polar lipids were phosphatidylethan...

Brown-rot fungi preferentially degrade softwood and cause severe breakdown of wooden structures. At the initial stage of the brown-rot decay, penetrating hyphae of the fungi are observed in ray parenchyma. Since starch grains are known to be present in the ray parenchyma of sapwood, investigation of the functions and roles of the starch-degrading e...

Background Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. In our previous study,...

Inonotus obliquus is a medicinal fungus in the family Hymenochaetaceae and commonly known as chaga. The sclerotium of this fungus has been used as a traditional medicine for long time. In this study, we present the mitochondrial genome sequence of I. obliquus. The mitochondrial DNA (mtDNA) is 119,110 base pairs in length and contained genes for 58...

Marchantia polymorpha is a model liverwort for which many molecular biological techniques are now available. We previously developed the S-AgarTrap method for easy genetic transformation of M. polymorpha using spores. In this study, we report production of a T-DNA insertion mutant library (approx. 10,000 lines) for M. polymorpha using the S-AgarTra...

Cellouronate is a (1,4)-β-D-glucuronan prepared by TEMPO-mediated oxidation from regenerated cellulose. We have previously isolated a cellouronate-degrading bacterial strain, Brevundimonas sp. SH203, that produces a cellouronate lyase (β-1,4-glucuronan lyase, CUL-I). In this study, the gene encoding CUL-I was cloned, and the recombinant enzyme was...

Anthocyanins are responsible for red, purple, and pink pigmentation of flowers in Cymbidium hybrids. Although anthocyanin content in all floral organs increases with flower development, they increase markedly in the tepals compared with the labella or columns. Using next-generation sequencing technology, we identified three anthocyanin biosynthesis...

Circular patterns called “fairy rings” in fields are a natural phenomenon that arises through the interaction between basidiomycete fungi and plants. Acceleration or inhibition of plant vegetative growth and the formation of mushroom fruiting bodies are both commonly observed when fairy rings form. The gene of an enzyme involved in the biosynthesis...

The complete nucleotide sequence of Tomato leaf curl New Delhi virus detected from melon in Indonesia-[Indonesia:Yogya:Melon:2015] (ToLCNDV-[ID:YG:Mel:15]) was determined. ToLCNDV-[ID:YG:Mel:15] has bipartite DNAs, and both DNAs showed highest identity to ToLCNDV-[Indonesia:Java:Cucumber:2008] (ToLCNDV-[ID:JV:Cuc:08]). However in a phylogenetic ana...

Quorum sensing is a cell density-dependent regulation of gene expression. N-Acyl-l-homoserine lactone (AHL) is a major quorum-sensing signaling molecule in gram-negative bacteria and synthesized by the LuxI family protein. The genus Serratia is known as a producer of the red pigment, prodigiosin, whose biosynthesis is dependent on the pig gene clus...

An α-L-fucosidase (Pap-Alf) was purified from the pancreas of a starfish Patiria pectinifera by ammonium sulfate precipitation followed by several column chromatographies. The molecular mass of the purified enzyme was estimated to be 52.6 kDa by SDS-PAGE, although gel filtration analysis of the native enzyme suggests it exists as a homodimer in sol...

A cysteine protease belonging to peptidase C1A superfamily from the eukaryotic, symbiotic dinoflagellate, Symbiodinium sp. strain KB8, was characterized. The protease was purified to near homogeneity (566-fold) by (NH4)2SO4 fractionation, ultrafiltration, and column chromatography using a fluorescent peptide, butyloxycarbonyl-Val-Leu-Lys-4-methylco...

Effects of metal ions on the VLKP activity. Each value is shown as a relative value based on the value of the control (distilled water). Each metal ion was at a final concentration of 1 mM. The counterion SO42– used for Cu2+ and Fe2+, and Cl−used for the other cations. Values represent the mean ± SE of three independent experiments. N.D., not detec...

Substrate specificity of the crude Symbiodinium sp. KB8 extract. A MES + HEPES + Tricine solution (pH 4–8) was used for the measurements. Synthetic fluorogenic peptides were each added to a final concentration of 0.1 mM. Values represent the mean ± SE of three independent experiments. (PDF)

Molecular mass determination of VLKP by Superdex 200 HiLoad 16/60 gel filtration. Molecular markers used: 1, thyroglobulin (669 kDa); 2, alcohol dehydrogenase (150 kDa); 3, BSA (66 kDa); 4, carbonic anhydrase (29 kDa). Kav = (VE−V0) (VC−V0)–1; V0, void volume (ml); VE, elution volume (ml); VC, geometric bed volume (ml). (PDF)

Optimum pH for VLKP activity. Maximum activity was assigned a value of 100%, and the activities in the other samples were scaled to that value. A succinate-borate buffer (0.1 M, SB) was used for pH values between 3.0 and 5.0, and a MES-HEPES-Tricine buffer (0.1 M, MHT) was used for pH values between 5.0 and 6.0. Values represent the mean ± SE of th...

Effects of heat treatment on VLKP activity and stability. Maximum activity was assigned a value of 100%, and the activities of the other samples were scaled to that value. Values represent the mean ± SE of three independent experiments. A, Optimum temperature determination. Activity of purified VLKP was measured between 20 and 50°C at 5°C intervals...

Time course of protease activity, chlorophyll content, and growth during Symbiodinium sp. KB8 culture. Protease activity is reported as the activity per amount of protein in the crude extract. Values represent the mean ± SE of three independent experiments. (PDF)

SDS-PAGE of fractions isolated by Superdex 200 HR 10/30 chromatography. Ten Superdex 200 HR 10/30 fractions (from elution volume 13.5 ml to 18 ml, see Fig 1) containing substantial activity were electrophoresed through an SDS-PAGE gel and silver stained. The activity of each fraction was also measured. The amount of protein in the upper band (31.3...

Synthetic fluorogenic peptides used in this study. The target substrate of each enzyme are described by reference of Peptide Institute (http://www.peptide.co.jp) and MEROPS (http://merops.sanger.ac.uk). (PDF)

Stropharia rugosoannulata (Strophariaceae, Basidiomycota) is an edible mushroom distributed in northern temperate zones throughout the world. In this study, the complete mitochondrial genome sequence of S. rugosoannulata was determined. This mitochondrial genome is 60,551 bp in length with a GC content of 31.0% and encodes 14 conserved proteins, 2...

Brown-rot fungi are the wood-decay basidiomycetes and have ability to break down plant cell wall carbohydrates. It has been suggested that degradation of pectin is important for the initial stages of brown rot. We purified an endo-polygalacturonase (FpPG28A) from the brown-rot fungus Fomitopsis palustris, analysis of the predicted amino acid sequen...

We investigated biofilm formation on biodegradable plastics in freshwater samples. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) was covered by a biofilm after an incubation in freshwater samples. A next generation sequencing analysis of the bacterial communities of biofilms that formed on PHBH films revealed the dominance of the order Burkh...

Salinity stress limits plant growth and productivity. To cope with this limitation, the expression patterns of numerous genes are altered in response to salt stress; however, the regulatory mechanisms involved in these changes are unclear. In the present study, we investigated the regulation of the salinity stress response in the liverwort Marchant...

Background: Increasing rice demand is one of the consequences of the steadily improving socio-economic status of the African countries. New Rice for Africa (NERICA), which are interspecific hybrids between Asian and African rice varieties, are one of successful breeding products utilizing biodiversity across the two different rice crop species. Up...