Koki Fujita

Kyushu University | Kyudai · Department of Agro-environmental Sciences

Cationic cell-wall-bound peroxidase (CWPO-C) from Populus alba is the only Class III peroxidase that has been shown to be able to oxidize high molecular weight lignin polymers from sinapyl alcohol and previously, has been believed to be a lignin polymerization-specific peroxidase. However, using an Arabidopsis heterologous expression system, we sho...

[This corrects the article DOI: 10.1007/s12298-022-01241-0.].

The poplar cationic cell-wall-bound peroxidase (CWPO-C) mediates the oxidative polymerization of lignin precursors, especially sinapyl alcohols, and high molecular weight compounds that cannot be oxidized by other plant peroxidases, including horseradish peroxidase C. Therefore, CWPO-C is believed to be a lignification-specific peroxidase, but dire...

The mechanism of lignin dehydrogenative polymerization (DHP), made by means of horseradish peroxidase (HRP), was studied in comparison with other plant peroxidases. Interestingly, HRP is efficient for guaiacyl type polymer formation (G-DHPs), but is not efficient in the case of syringyl type DHPs (S-DHPs). It was previously demonstrated that lignif...

The evaluation of houses made of wood has been raised again in recent years. For houses made of wood, the odor of the wood is one of the important factors. The volatile compounds released from the wood can change over the year because of large variations in temperature and humidity in Japan with four seasons. In this study, volatile compounds in a...

Most of the known 4-coumarate:coenzyme A ligase (4CL) isoforms lack CoA-ligation activity for sinapic acid. Therefore, there is some doubt as to whether sinapic acid contributes to sinapyl alcohol biosynthesis. In this study, we characterized the enzyme activity of a protein mixture extracted from the developing xylem of Robinia pseudoacacia. The c...

A cell culture of Cupressus lusitanica was used to investigate the reaction of a plant to certain airborne chemicals. Compared with laboratory and field methods using intact plants or tissues, a cell culture is advantageous because it is not affected by environmental factors, and the experiments are easier to reproduce. When exposed to an elicitor,...

Plant class III heme peroxidases catalyze lignin polymerization. Previous reports have shown that at least three Arabidopsis thaliana peroxidases, AtPrx2, AtPrx25 and AtPrx71, are involved in stem lignification using T-DNA insertion mutants, atprx2, atprx25, and atprx71. Here, we generated three double mutants, atprx2/atprx25, atprx2/atprx71, and a...

Cultured Cupressus lusitanica cells induced by various stresses are thought to produce different complexes of defense chemicals to optimize defense. To compare the induced products of two stimulations, we investigated the emission of monoterpenes, biosynthesis of β-thujaplicin, and accumulation of lignin in mechanically stressed and fungal elicited...

We showed previously that in Cupressus lusi-tanica (Mexican cypress), the first two steps of terpinolene oxidation, beginning at hydroxylation at the aryl position and then forming epoxide at the double bond, were driven by cytochrome P450s. The significance of enantio differ-ences, in general, has received attention because those enantiomers often...

Lignins are aromatic heteropolymers that arise from oxidative coupling of lignin precursors, including lignin monomers (p-coumaryl, coniferyl, and sinapyl alcohols), oligomers, and polymers. Whereas plant peroxidases have been shown to catalyze oxidative coupling of monolignols, the oxidation activity of well-studied plant peroxidases, such as hors...

β-Thujaplicin is a wood monoterpene and tropolone compound with a unique conjugated 7-membered ring. Because of its strong antifungal and antitumor activities, β-thujaplicin is used in several fields. The biosynthesis pathway of β-thujaplicin has not yet been elucidated. Using Cupressus lusitanica cell cultures in a radioisotope feeding experiment,...

Caryophyllene-6,7-epoxide and caryophyllene-6,7-episulfi de can be easily synthesized from β-caryophyllene by autoxidation or episulfi dation. The bioactivities of β-caryophyllene and its derivatives were investigated against the subterranean termite Reticulitermes speratus Kolbe. The antifeedant, feeding, and termiticidal activities of each compou...

The final step of lignin biosynthesis, which is catalyzed by a plant peroxidase, is the oxidative coupling of the monolignols to growing lignin polymers. Cationic cell-wall-bound peroxidase (CWPO-C) from poplar callus is a unique enzyme that has oxidative activity for both monolignols and synthetic lignin polymers. We show that putative CWPO-C homo...

Many of monoterpenes produced in plants contribute to defenses against herbivores, insects and microorganisms. Among those compounds, β-thujaplicin formed in Cupressaceae plants has a unique conjugated seven-membered ring and some useful biological activities, e.g. fungicide, repellent, insecticide and so on. The biosynthesis pathway of β-thujaplic...

This paper addresses the identification of (E)-5-formyl-2,3,3′,4′-tetramethoxystilbene (11), a major tetramethylammonium hydroxide (TMAH) thermochemolysis product of guaiacyl dehydrogenation polymer (DHP). It was carried out by comparing the mass spectral data and chromatographic behavior with those of authentic (E)-11, which was prepared by off-li...

Phenolic 2-arylcoumarans 1–6 were used to examine the behaviors of β-5 subunits in lignin during tetramethylammonium hydroxide (TMAH) thermochemolysis. Products were monitored by gas chromatography/mass spectrometry. The process predominantly provided dimeric products with the opened hydrofuran ring. Substituent changes at the γ-position of ring A...

Direct episulfidations of caryophyllene or humulene with elemental sulfur were examined by means of gas chromatography. Caryophyllene-6,7-episulfide was formed at an early stage in a reaction of the caryophyllene and elemental sulfur at 120 degrees C. Caryophyllene-3,6-sulfide and polymer compounds were formed after the episulfidation. Formations o...

1,2-Diarylpropane-1,3-diol-type lignin model compounds, 1,2-bis(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (1) and 1-(3,4-diethoxyphenyl)-2-(4-methoxyphenyl)propane-1,3-diol (2), were pyrolyzed at 500 degrees C for 4 s to clarify the thermal behavior of beta-1 subunits in lignin. Products were monitored by gas chromatography/mass spectrometry. The...

Beta-thujaplicin Is a natural troponoid with strong antifungal, antiviral, and anticancer activities. Beta-thujaplicin production in yeast elicitor-treated Cupressus lusitanica cell culture and its relationships with reactive oxygen species (ROS) and nitric oxide (NO) production and hypersensitive cell death were investigated. Superoxide anion radi...

beta-Thujaplicin is an antimicrobial tropolone derived from geranyl pyrophosphate(GPP) and monoterpene intermediate. Yeast elicitor-treated Cupressus lusitanica cell cultures accumulate high levels of beta-thujaplicin at early stages and other monoterpenes at later stages post-elicitation. The different regulation of beta-thujaplicin and monoterpen...

Oxidative stress is a common physiological stress that often challenges plants. Reactive oxygen species (ROS) are major factors in oxidative stress that significantly affect plant cell growth and secondary metabolism. Here we used beta-thujaplicin production by Cupressus lusitanica cell culture as an example to demonstrate the common occurrence of...

Roles of jasmonate and ethylene signalling and their interaction in yeast elicitor-induced biosynthesis of a phytoalexin, beta-thujaplicin, were investigated in Cupressus lusitanica cell cultures. Yeast elicitor, methyl jasmonate, and ethylene all induce the production of beta-thujaplicin. Elicitor also stimulates the biosynthesis of jasmonate and...

Summary • An increasing body of evidence on plant electrophysiology, biochemistry, and molecular biology shows that cAMP exists in higher plants and plays a role in several physiological processes by affecting potassium (K+) or calcium (Ca2+) fluxes. Our study here reports that cAMP is involved in elicitor-induced accumulation of a phytoalexin, β-t...

A novel monoterpene, (1S, 2S, 6S)-(+)-1,6-epoxy-4(8)-p-menthen-2-ol, was isolated from an elicitor-treated cell culture of Cupressus lusitanica (Mexican cypress). Ten known monoterpenes--limonene, myrcene, beta-ocimene, sabinene, terpinolene, 4-terpineol, alpha-terpineol, 4(8)-p-menthen-1,2-diol, 4-hydroxyphellandric acid methylester and beta-thuja...

 The optimum conditions for β-thujaplicin production in a Cupressus lusitanica cell suspension culture were investigated. The conditions required for β-thujaplicin production were clearly different from the conditions for cell growth. The initial phosphate concentration and pH did not affect β-thujaplicin production. A total nitrogen source concent...

 Conditions for cell growth of suspension cultures of Cupressus lusitanica, which has high β-thujaplicin productivity, were studied. The medium that provided the highest growth rate was IS-1 medium (pH 5.5), modified from Gamborg B5 medium containing 32 mM of total nitrogen. Its NO3-N/NH4-N ratio was 30 : 2. The maximum growth represented a 25-fold...

Suspension cell cultures of Cupressus lusitanica produce beta-thujaplicin, a tropolone found mostly in Cupressaceae heartwood. The factors controlling beta-thujaplicin accumulation in this cell culture system were investigated. Initial cell density of the cultures did not affect beta-thujaplicin levels, though initial addition of beta-thujaplicin s...

Suspension cell culture of Cupressus lusitanaca produce β-thujaplicin, a heart wood tropolone. The product inhibition in the β-thujaplicin biosynthesis was investigated in the present paper. Initial cell density at the beginning in the culture did not affect the β-thujaplicin accumulation level, and the initial addition of β-thujaplicin to the cult...

Production of a novel antimicrobial tropolone, beta-thujaplicin, in Cupressus lusitanica suspension cultures was studied by using a variety of chemicals and fungal elicitors. Sodium alginate, chitin, and methyl jasmonate resulted in 2-, 2.5-, and 3-fold higher beta-thujaplicin production, respectively, than in the control. Significantly improved be...

Effects of some organic acids and monoterpenes on production of β-thujaplicin were studied in Cupressus lusitanica suspension cultures. The fungal elicitor-induced biosynthesis of β-thujaplicin was promoted by the feedings of malate, pyruvate, fumarate, succinate, and acetate. These results suggest some relationships between acetate/pyruvate metabo...

The biosynthesis pathway of β-thujaplicin,which has a unique conjugated seven-membered ring structure, was investigated using the Cupressus lusitanica cell culture. We also examined a transformation of the carbon skeleton during its biosynthesis. Incorporation of [10-14C] geraniol into β-thujaplicin in the cell culture revealed that this compound w...

Ethyl acetate extracts ofCupressus lusitanica suspension cell cultures were examined for their biological activities (viz., tyrosinase inhibitory, antioxidant, and antimicrobial activities). The extract from elicitor-treated cells showed all of the biological activities, whereas the extract from cultures without elicitor was not bioactive to a disc...

One of wood tropolones, ß-thujaplicin, exists in heartwood of some species in Cupressaceae. Biosynthesis pathway of ß-thujaplicin has been interested because it has unique conjugated seven-membered ring and there has been no experimental evidence which suggests its biosynthesis pathway. Therefore, first of all we tried 14C-geraniol feeding experime...

A novel monoterpene, (1S, 2S, 6S)-(+)-1,6-epoxy-4(8)-p-menthen2-01, was isolated from an elicitor-treated cell culture of Cupressus lusitanica (Mexican cypress). Ten known monoterpenes - limonene, myrcene, $ \beta $-ocimene, sabinene, terpinolene, 4-terpineol, $ \alpha $-terpineol, 4 (8) -p-menthen-l,2-diol, 4-hydroxyphellandric acid methylester an...

メキシコイトスギ(Cupressus lusitanica)の培養細胞は酵母抽出物などのエリシターの刺激によって高い生産性で細胞内外にヒノキチオールを生産することが報告されている.培養細胞を用いた植物二次代謝成分生産の実用化に適した液体懸濁培養条件を検討し,大規模化・自動化の可能性を検討するためにジャーファーメンターによる細胞培養とヒノキチオール生産を試みた.三角フラスコを用いた小規模な液体懸濁培養系では,GamborgのB5培地を基本にした培地で良好な細胞成長とヒノキチオール生産がみられた.スケールアップのため同じ培地組成で撹拌式ジャーファーメンターとエアリフト式ジャーファーメンターを用いて培養を行った.エアリフト式では良好な成長率が得られたが,撹拌式では成長率は低かった.ヒノキチオール生...