First Report of Sclerotinia Rot Caused by Sclerotinia sclerotiorum on Artemisia capillaris in China.

Artemisia capillaris (Asteraceae) is an annual herb found in ˃10 provinces in China. It is cultivated on ˃670 ha, with annual production around 2,500 tons. Its shoot is used in traditional Chinese medicine (Liu et al. 2021). From April to May 2023, Sclerotinia rot symptoms were seen at the Institute of Medicinal Plant Development (40.04°N, 116.28°E), Beijing, China. Disease incidence was up to 10% in the field through investigation of 300 plants. Initial symptoms were irregular tan-brown lesions (0.5 to 5.0 mm) that expended to circumferential necrosis on the roots and basal stem, aerial mycelia and sclerotia were developed on them. The leaves and stem tips were withered and droopy in severe cases. Twelve symptomatic primary roots of 12 plants from two sites were cut into 5 × 5 mm pieces, surface sterilized with 75% ethanol for 30 s and 5% NaClO for 60 s, rinsed with distilled water for three times, dried with sterile filter paper, put on potato dextrose agar (PDA), and incubated at 25°C in the dark for 2 days. Two Sclerotinia-like isolates were obtained using the hyphaltip method. White aerial mycelia were sparse and appressed for isolate YC1-3 and dense for isolate YC1-7. After incubated at 25°C in the dark for 15 days, 10 to 25 sclerotia were developed near the colony margin. Sclerotia of isolate YC1-3 were 1.0 to 3.9 × 1.2 to 4.5 (mean 1.8 × 2.2) mm (n = 60), ovoid or arc-shaped. Sclerotia of isolate YC1-7 were 1.5 to 3.4 × 2.7 to 9.2 (mean 2.3 × 4.3) mm (n = 60), ovoid, dumbbell shaped or curved. The isolates were identified as Sclerotinia sclerotiorum based on morphology (Maas 1998). To further identify the pathogens, molecular identification was performed with isolates YC1-3 and YC1-7. DNA of the two isolates were extracted by the cetyltrimethylammonium bromide (CTAB) method. Polymerase chain reaction was performed with primers ITS1/ITS4 for the internal transcribed spacer (ITS) region (Choi et al. 2020; White et al. 1990) and primers G3PDHfor/G3PDHrev for the glyceraldehyde 3-phosphate dehydrogenase (G3PDH) gene (Garfinkel. 2021). BLAST search analysis revealed that the ITS sequence (GenBank OR229758 and OR229762) was ≥99% similar to S. sclerotiorum (MN099281, MZ379265, KX781301, etc.), and the G3PDH sequence (OR778388 and OR761975) was too (MZ493894, JQ036048, OQ790148, etc.). Phylogenetic trees were computed with ITS and G3PDH sequences using the Maximum Likelihood in MEGA 11. Nine two-month-old seedlings of A. capillaris were used to test pathogenicity. The epidermis layer of each primary root was slightly wounded (2 × 2 mm, 1 mm deep) using a sterile dissecting blade. Three plants were inoculated with mycelial plugs (5 mm in diameter) of YC1-3 and YC1-7 that cultured on PDA for 7 days. Control plants were inoculated with sterile PDA plugs. All seedlings were then incubated at 25oC and 90% relative humidity. After isolate YC1-7 inoculation 3 days and isolate YC1-3 inoculation 5 days, inoculated roots had symptoms like those in the field, controls had no symptoms. S. sclerotiorum was consistently re-isolated from diseased roots, fulfilling Koch's postulates. Diseases caused by S. sclerotiorum have been reported threatens several important economical crops (Marin and Peres 2020; Guan et al. 2022). To our knowledge, this is the first report of S. sclerotiorum causes Sclerotinia rot on A. capillaris. To avoid of significant economic losses, it is urgent to establish an effective disease-management strategy.

[Anxiolytic and antidepressant effects of agarwood inhalation and its mechanism].

This study used m-chloropheniperazine(MCPP) and chronic unforeseeable mild stress(CUMS) to induce the rat models of anxiety and depression, respectively. The behaviors of rats were observed by the open field test(OFT), light-dark exploration test(LDE), tail suspension test(TST), and forced swimming test(FST), and the antidepressant and anxiolytic effects of agarwood essential oil(AEO), agarwood fragrant powder(AFP), and agarwood line incense(ALI) were explored. The enzyme-linked immunosorbent assay(ELISA) was used to determine the levels of 5-hydroxytryptamine(5-HT), glutamic acid(Glu), and γ-aminobutyric acid(GABA_A) in the hippocampal area. The Western blot assay was used to determine the protein expression levels of glutamate receptor 1(GluR1) and vesicular glutamate transporter type 1(VGluT1), exploring the anxiolytic and antidepressant mechanism of agarwood inhalation. The results showed that compared with the anxiety model group, the AEO, AFP, and ALI groups decreased the total distance(P<0.05), decreased the velocity of movements(P<0.05), prolonged the immobile time(P<0.05), and reduced the distance and velocity of the rat model of anxiety in the dark box(P<0.05). Compared with the depression model group, the AEO, AFP, and ALI groups increased the total distance and average velocity(P<0.05), reduced the immobile time(P<0.05), and reduced the forced swimming and tail suspension time(P<0.05). In terms of transmitter regulation, the AEO, AFP, and ALI groups decreased the level of Glu in the rat model of anxiety(P<0.05) and increased the levels of GABA_A and 5-HT(P<0.05), while the AEO, AFP, and ALI groups all increased the level of 5-HT in the rat model of depression(P<0.05) and decreased the levels of GABA_A and Glu(P<0.05). At the same time, the AEO, AFP, and ALI groups all increased the protein expression levels of GluR1 and VGluT1 in the hippocampus of the rat models of anxiety and depression(P<0.05). In conclusion, AEO, AFP, and ALI exert anxiolytic and antidepressant effects, and the mechanism might be related to the regulation of the neurotransmitter and the protein expression of GluR1 and VGluT1 in the hippocampus.

[Two new sesquiterpenes in Qi-nan Aquilariae Lignum Resinatum].

This study aimed to investigate the chemical constituents of supercritical extract from Qi-nan Aquilariae Lignum Resinatum by silica gel column chromatography, thin-layer chromatography, and semi-preparative high-performance liquid chromatography. One new elemane-type and one new eudesmane-type sesquiterpene compounds were isolated from the extract, and their structures were identified by MS, UV, IR, NMR, and ECD spectroscopic techniques, and named aquqinanol C(1) and aquqinanol D(2). Both compounds are novel compounds. The neuroprotective effect of the compounds on CORT-induced PC12 cell damage was determined in vitro. The results showed that compounds 1 and 2 exhibited a certain protective effect against CORT-induced damage in PC12 cells.

Genome-wide investigation and expression analysis of the AP2/ERF family for selection of agarwood-related genes in Aquilaria sinensis (Lour.) Gilg.

Aquilaria sinensis is an important non-timber tree species for producing high-value agarwood, which is widely used as a traditional medicine and incense. Agarwood is the product of Aquilaria trees in response to injury and fungal infection. The APETALA2/ethylene responsive factor (AP2/ERF) transcription factors (TFs) play important roles in plant stress responses and metabolite biosynthesis. In this study, 119 AsAP2/ERF genes were identified from the A. sinensis genome and divided into ERF, AP2, RAV, and Soloist subfamilies. Their conserved motif, gene structure, chromosomal localization, and subcellular localization were characterized. A stress/defense-related ERF-associated amphiphilic repression (EAR) motif and an EDLL motif were identified. Moreover, 11 genes that were highly expressed in the agarwood layer in response to whole-tree agarwood induction technique (Agar-Wit) treatment were chosen, and their expression levels in response to methyl jasmonate (MeJA), salicylic acid (SA), or salt treatment were further analyzed using the quantitative real time PCR (qRT-PCR). Among the 11 genes, eight belonged to subgroup B-3. All 11 genes were significantly upregulated under salt treatment, while eight genes were significantly induced by both MeJA and SA. In addition, the gene clusters containing these upregulated genes on chromosomes were observed. The results obtained from this research not only provide useful information for understanding the functions of AP2/ERF genes in A. sinensis but also identify candidate genes and gene clusters to dissect their regulatory roles in agarwood formation for future research.

Cadinane-Type Sesquiterpenoids with Cytotoxic Activity from the Infected Stems of the Semi-mangrove Hibiscus tiliaceus.

Eight new cadinane sesquiterpenoids (1-8), along with two known compounds (9 and 10), were isolated from infected stems of the semi-mangrove plant, Hibiscus tiliaceus. The structures of compounds 1-8 were elucidated through the analysis of their 1D and 2D NMR and MS data, and their absolute configurations were determined by comparing their experimental and calculated ECD spectra and by single-crystal X-ray diffraction. The two confused known compounds (9 and 10) were resolved using single-crystal X-ray crystallography. Compounds 1-3 have novel norsesquiterpene carbon skeletons arising from a ring contraction rearrangement. All obtained isolates were evaluated against the HepG2 and Huh7 cell lines, and compounds 1b, 2b, 4, 6, and 8 showed cytotoxic activity toward both cell lines, with IC50 values ranging from 3.5 to 6.8 µM.

Cadinane-type sesquiterpenoid dimeric diastereomers hibisceusones A-C from infected stems of Hibiscus tiliaceus with cytotoxic activity against triple-negative breast cancer cells.

Three new cadinane-type sesquiterpenoid dimeric diastereomers (1-3) named hibisceusones A-C were obtained from the infected stems of Hibiscus tiliaceus. The structures were determined by NMR spectroscopy and MS techniques, and the absolute configurations were assigned by ECD and single-crystal X-ray diffraction techniques. Compounds 1-3 are diastereomers, and contain a 1,4-dioxane ring linearly fused to different cadinane-type polycyclic skeletons. This is the first time that such a structure has been identified in natural products. Compounds 1-3 exhibited cytotoxic activities, and 2 showed a significantly high anti-triple-negative breast cancer (TNBC) effect. The anti-cancer effect of compound 2 was 3-4 fold higher than that of 1 and 3. The anti-cancer effect was generated via the induction of the apoptosis of the MDA-MB-231 cells by inhibiting the PI3Kα pathway.

[Analysis and suggestions on harvest period standards of plant medicinal materials in 2020 edition of Chinese Pharmacopoeia].

The improvement of the harvest period standards is critical in the quality control of Chinese medicinal materials. The present study statistically analyzed the harvest period standards of plant medicinal materials in the 2020 edition of Chinese Pharmacopoeia(Vol.Ⅰ) and put forward the existing problems and suggestions based on herbal records and modern research to provide references for the improvement of the standards. According to the statistical analysis, in 499 types of plant medicinal materials, harvest period standards are recorded under 486 types, accounting for 97.4%, and are lacking in the remaining. Only one medicinal material(Stellariae Radix) is recorded with the standard of the harvest year. The standards of the harvest season and phenological period are recorded under 233 types, accounting for 46.7%. For 237 types, only harvest season is specified, accounting for 47.5%, and for 15 types, only harvest phenological period is specified, accounting for 3.0%. Among 222 types mainly derived from cultivation and 51 types from wild resources and cultivation, only 11 types are recorded with harvest period of cultivated products. Only Stellariae Radix is recorded with the harvest period standards for the wild and cultivated products separately. The harvest period standards of plant medicinal materials with different medicinal parts have certain rules to follow. The main problems about the harvest period standards are discovered. Specifically, no harvest period standards are recorded under 13 types of plant medicinal materials. Almost all perennial cultivated medicinal materials are not recorded with harvest year standard. No phenological period standard is found under 250 types of plant medicinal materials. There is no clear distinction between the harvest period standards of cultivated and wild products. The evidence for harvest period standards of 26 types of plant medicinal materials that can be harvested all year round is insufficient. As a result, it is proposed to strengthen basic research in response to the above-mentioned problems and improve the harvest period standards as soon as possible to ensure the quality of Chinese medicinal materials.

[Anti-asthmatic effect of agarwood alcohol extract in mice and its mechanism].

As recorded, agarwood has the function of improving qi reception and relieving asthma, but the underlying mechanism is unclear and rarely reported. Therefore, this study explored the anti-asthmatic effect of the alcohol extract of agarwood produced by the whole-tree agarwood-inducing technique(Agar-Wit) in the asthma mouse model induced by intraperitoneal injection of ovalbumin(OVA) + Al(OH)_3 combined with intranasal administration of OVA and the mechanism, and compared the anti-asthmatic effects of agarwood induced with different methods. Firstly, the anti-inflammatory and anti-asthmatic effects of Agar-Wit agarwood in mice were evaluated based on the asthma frequency, lung tissue injury, and peripheral inflammatory white blood cell(WBC) count and eosinophil count. Then, the levels of interleukin-1ß(IL-1ß), IL-17, and IL-10 in serum of mice were detected by enzyme-linked immunoassay(ELISA) and the expression of inflammation-and apoptosis-related genes in tissues was measured by reverse transcription polyme-rase chain reaction(RT-PCR) so as to preliminarily explore the anti-asthmatic mechanism. RESULTS:: showed that the alcohol extract of Agar-Wit agarwood significantly reduced asthma frequency, relieved pathological injury, improved peripheral WBC count and eosinophil count, decreased the levels of inflammatory cytokines IL-1ß and IL-17, elevated the level of anti-inflammatory cytokine IL-10, and down-regulated the mRNA expression of IL-1 R, tumor necrosis factor receptor R(TNFR), nuclear transcription factor-kappa B(NF-κB), Bax, and caspase 3, but had no significant influence on the expression of high-mobility group box 1(HMGB1) protein, caspase 8, and Bcl-2. The effect of Agar-Wit agarwood alcohol extract was better than that of wild agarwood alcohol extract and alcohol extract of agarwood induced with the burning-chisel-drilling method at the same dose. In conclusion, Agar-Wit agarwood can significantly alleviate inflammation and asthma, which is related to its anti-inflammation and anti-apoptosis activity.

WRKY44 represses expression of the wound-induced sesquiterpene biosynthetic gene ASS1 in Aquilaria sinensis.

Agarwood is derived from wounds in Aquilaria trees and is widely used in traditional medicine, incense, and perfume. Sesquiterpenes are one of the main active components in agarwood and are known to be induced by wounding or injury; However, the molecular mechanisms by which wounding leads to sesquiterpene formation remain largely unknown. Agarwood sesquiterpene synthase 1 (ASS1) is one of key enzymes responsible for the biosynthesis of sesquiterpenes and is a crucial jasmonate (JA)-responsive wound-inducible synthase. However, it is not known why ASS1 is not expressed in healthy trees and how its expression is induced as a result of wounding. Here, we report that ASS1 is a wound-induced gene with a promoter in which a 242-bp region (-973 to -731bp) is identified as the core sequence for responding to wound signals. AsWRKY44 binds directly to this region and represses ASS1 promoter activity. Down-regulation or disruption of AsWRKY44 can relieve the inhibition and activate ASS1 expression. In addition, AsWRKY44 is degraded and the expression of ASS1 is significantly up-regulated in response to exogenous application of methyl jasmonate. Thus, AsWRKY44 is a crucial negative regulator of wound-induced ASS1 transcription, and is central to the mechanism of sesquiterpene biosynthesis in agarwood.

Bioactive flavonoid dimers from Chinese dragon's blood, the red resin of Dracaena cochinchinensis.

Seven flavonoid dimers, biflavocochins A-G, together with six known compounds were isolated from the red resins of Dracaena cochinchinensis (Chinese dragon's blood). Their structures were elucidated based on extensive spectroscopic analysis. The absolute configurations of 1-7 was assigned by experimental and quantum chemical calculated ECD spectra, and that of 4 was further established by X-ray diffraction analysis using Cu Kα radiation. Compounds 1-3 are novel dimers of homoisoflavonoid and dihydrochalcone with a unique dibenzopyran ring. Compounds 2, 6, 7 exhibited moderate PTP1B inhibitory activities in an enzyme assay. Compound 1 showed neuroprotective effect on serum deficiency-induced cellular damage in PC12 cells.

[Characterization of AOX family members from Aquilaria sinensis and their responses to wounding].

Aquilaria sinensis is a typical inducible medicinal plant, that can produce agarwood only after it is wounded by external stimuli. Alternative oxidase(AOX) is one of the terminal oxidases of the plant mitochondrial electron transport, which plays an important role in plants' response to environmental stress. In order to reveal the physiological function of AOX gene in the process of agarwood formation from A.sinensis induced by wounding, AOX gene was cloned based on the transcriptome database and then identified by the bioinformatics analysis, and their expression pattern in different tissues and under wounding stress were detected by qRT-PCR. The results as follows. Three AOX genes were cloned from A.sinensis for the first time. They were named AsAOX1a, AsAOX1d and AsAOX2, respectively. The tissue expression shown that AsAOX1a is mainly expressed in the stem and the seed, and the AsAOX1d and AsAOX2 genes are mainly expressed in the pulp and the stem. AsAOX1a and AsAOX1d genes are highly responsive to wounding stress, and their response time was different. In addition, the expression of AsAOX1a and AsAOX2 induced by wounding are reduced by H_2O_2 treatment, but promoted by AsA treatment. The cloning, bioinformatics analysis and expression characteristics of AOX genes from A.sinensis provided basic information for further study the function of AOX genes in the development of A.sinensis, especially in the process of agarwood formation of A. sinensis induced by wounding.

Sesquiterpenoids with cytotoxicity from heartwood of Dalbergia odorifera.

Two new sesquiterpenoids, named dalodorin A (1) and dalodorin B (2), together with four known sesquiterpenoids, were isolated from the heartwood of Dalbergia odorifera. Their structures were elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques and HR-ESI-MS. Evaluation of the isolated compounds for cytotoxicity against two human cancer cell lines (Hela and HepG-2) showed moderate activities (25.22-60.45 µM).

[Anti-inflammatory sesquiterpenes from agarwood produced via whole-tree agarwood-inducing technique of Aquilaria sinensis].

The present study is to investigate the chemical constituents and anti-inflammation of agarwood produced via whole-tree agarwood-inducing technique( Agar-Wit) from Aquilaria sinensis by column chromatographic technique and semi-preparation HPLC.Eleven sesquiterpenes were isolated from the agarwood produced by Agar-Wit,and their structures were identified on the basis of physiochemical characteristics and spectroscopic data analysis as baimuxinol( 1),5α,7α( H)-eudesm-11( 13)-en-4α-ol( 2),( 7 S,9 S,10 S)-( +)-9-hydroxy-selina-4,11-dien-14-al( 3),petafolia A( 4),7( 11)-eremophilen-8-one( 5),neopetasane( 6),petafolia B( 7),11-hydroxy-valenc-1( 10)-en-2-one( 8),( 4αß,7ß,8αß)-3,4,4α,5,6,7,8,8α-octahydro-7-[1-( hydroxymethyl) ethenyl]-4α-methylnaphthalene-1-carboxaldehyde( 9),12-hydroxy-4( 5),11( 13)-eudesmadien-15-al( 10),and( 4 R,5 R,7 S,9 S,10 S)-(-)-eudesma-11( 13)-en-4,9-diol( 11). Among them,compound 1 was a new natural product,and this is the first time to report its13 CNMR spectroscopic data. Compounds 4,9 and 10 were reported from Aquilaria for the first time,and all the compounds are firstly isolated by Agar-Wit from A. sinensis. The anti-inflammatory activity of RAW264. 7 cells with lipopolysaccharide-induced was evaluated.As a result,1,4 and 9 showed potential anti-inflammatory activities with IC50 values( 2. 5±0. 35),( 3. 2±0. 2),( 4. 3±0. 56) µmol·L-1,respectively. This work provided scientific foundation for quality evaluation of the agarwood produced by Agar-Wit.

[Genome survey analysis and SSR loci mining of Bupleurum falcatum].

Buplewrum falcatum is a traditional Chinese medicine,which is mainly used for the treatment of cold and liver protection. B. falcatum is dominantly cultivated in Japan as well as planted in China,Korea and other countries and regions. In order to determine the appropriate sequencing strategy,the genome survey before large-scale genome sequencing is needed. This survey can provide information about the size and complexity of the whole genome of the target species. In the present study,the next generation sequencing technology( Illumina Hiseq 2000) was used to analyze the genome size and complexity of B. falcatum. In addition,SSR loci were analyzed from the sequenced data. Primer 3 was used to design specific primers and 33 pairs of primers were randomly selected for PCR with template DNA of B. falcatum,and the PCR system and optimal annealing temperature were screened. A total of 288. 64 G genome sequence data was obtained,and the estimated genome size of B. falcatum was 2 119. 58 Mb. The measured genome data depth was138×; the rate of heterozygosity was 1. 84%; and the ratio of repeat sequence was 83. 89%. It is speculated that the genome of B. falcatum is complex. The preliminary assembly was performed with K-mer = 41,and the contig N50 was 224 bp,the total length 896. 97 Mb,the scaffold N50 313 bp,and the total length was 922. 67 Mb. A total of 91 377 SSR sequences were detected in the sequenced genome data which were distributed in 70 809 unigenes.The main type is dinucleotide repeats,with 49 680 sequences,accounting for70. 16%. Among the 33 pairs of primers randomly synthesized according to the obtained SSR sequences,21 pairs were successfully amplifying the target sequences. The results will be helpful for later large scale genome sequencing and SSR molecular markers development for germplasm identification and trait mapping.

[Advances in study of plant type â ¢ polyketide synthases].

Polyketides are a large class of natural products with notable structural diversity and different biological activities. They have essential pharmacological value for human health. In plants, the enzymes responsible for the formation of phenolic metabolites backbone structures are collectively known as type Ⅲ polyketide synthases (PKSs), which are the key enzymes for the polyketides biosynthesis. The PKSs catalyze a series of condensation reactions of two-carbon acetate units with an acyl starter. A brief overview of this group of enzymes, including their reaction mechanisms, function modification, expression regulation, molecular evolution, and recent interesting findings are presented here.

[Research of pollution-free and precision cultivation system of Chinese herbal medicines].

The issues of disordering production and non-standard pesticide application are common in the production of Chinese herbal medicines. Aimed to above problems, research groups built the pollution-free and precision cultivation system of medicinal plants. This system mainly included the precise site selection of medicinal plants based on the GIS technology, modern omics-assisted breeding, metagenomics guiding the soil complex improvement, and the precise field management based on rational application of fertilizer and comprehensive control of disease. At present, the production and distribution of medicinal plants were performed in the many poor counties of the whole nation. The breeding platform of resistant varieties was built, and certificates of new and well-bred varieties were received, in the base of genetic backgrounds of the original species of medicinal plants. The disease incidences were declined after application of these resistant varieties. Additionally, chemical pesticide consumption of medicinal plants (such as Panax ginseng, P. notoginseng, Salvia miltiorrhiza, P. quinquefolium, Schisandra chinensis, Platycodon grandiflorum and P. grandiflorus etc.) reduced by 20%-80% based on the genetic testing technologies of plant diseases and insect pests and safety evaluation of pollution-free pesticides. The application of pollution-free and precision cultivation system of Chinese herbal medicines achieve significantly social, economic and ecological benefits.

Transcription Factor AsMYC2 Controls the Jasmonate-Responsive Expression of ASS1 Regulating Sesquiterpene Biosynthesis in Aquilaria sinensis (Lour.) Gilg.

Sesquiterpenes are one of the most important defensive secondary metabolite components of agarwood. Agarwood, which is a product of the Aquilaria sinensis response to external damage, is a fragrant and resinous wood that is widely used in traditional medicines, incense and perfume. We previously reported that jasmonic acid (JA) plays an important role in promoting agarwood sesquiterpene biosynthesis and induces expression of the sesquiterpene synthase ASS1, which is a key enzyme that is responsible for the biosynthesis of agarwood sesquiterpenes in A. sinensis. However, little is known about this molecular regulation mechanism. Here, we characterized a basic helix-loop-helix transcription factor, AsMYC2, from A. sinensis as an activator of ASS1 expression. AsMYC2 is an immediate-early jasmonate-responsive gene and is co-induced with ASS1. Using a combination of yeast one-hybrid assays and chromatin immunoprecipitation analyses, we showed that AsMYC2 bound the promoter of ASS1 containing a G-box motif. AsMYC2 activated expression of ASS1 in tobacco epidermis cells and up-regulated expression of sesquiterpene synthase genes (TPS21 and TPS11) in Arabidopsis, which was also promoted by methyl jasmonate. Our results suggest that AsMYC2 participates in the regulation of agarwood sesquiterpene biosynthesis in A. sinensis by controlling the expression of ASS1 through the JA signaling pathway.

Four New 2-(2-Phenylethyl)chromone Derivatives from Chinese Agarwood Produced via the Whole-Tree Agarwood-Inducing Technique.

Four new 2-(2-phenylethyl)chromone derivatives (1-4) were isolated from the EtOH extract of Chinese agarwood produced via the whole-tree agarwood-inducing technique, coming from Aquilaria sinensis (Lour.) Spreng. (Thymelaeaceae). Their structures were elucidated by extensive spectroscopic methods, such as UV, IR, MS, 1D as well as 2D NMR. All of the isolates were then assessed for their anti-inflammatory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7. Compound 1 exhibited significant inhibitory activity with an IC50 value of 4.6 µM.

[Prokaryotic expression and purification of Aquilaria sinensis(Lour.) Gilg AsMYC2 protein].

The MYC2 transcription factor is a member of the important plant b HLH transcription factor families, and it is also the core regulatory elements in jasmonate（JA） signaling pathway. However, there is a little information about AsMYC2 gene in Aquilaria sinensis. In this study, with the total RNA isolated from A. sinensis leave as template, the full-length coding sequence (CDS) of AsMYC2 gene was amplified using RT-PCR method and subcloned into pGEX-4T-1 vector by the gene recombination technique. The recombinant vector pGEX-4T-1-AsMYC2 was verified by restriction enzyme digestion and nucleotide sequencing, and was transformed into E. coli BL21（DE3） to express the protein. A maximum expression of soluble protein was observed with induction by 0.1 mmol·L(-1) IPTG at 37 ℃ for 4 hours. The fusion protein was purified through a Sepharose-Glutathione column, and verified by SDS-PAGE and Western blotting using an anti-GST polyclonal antibody. We successfully constructed the GST-AsMYC2 plasmid, produced and purified the GST-AsMYC2 fusion protein, which would provide the basic material for polyclonal antibody preparation, interactive factors screening and gene function research. According to the tissue-specific expression pattern analysis by q RT-PCR method, the AsMYC2 gene in A. sinensis tissues is mainly expressed in roots and stems, the main agarwood formation parts, and lowest expressed in leaves. These results indicate that AsMYC2 gene likely play some roles in agarwood formation in A. sinensis.

[Viability of 7 kinds of medicinal plant seeds stored in medium-term gene bank of the National Medicinal Plant Gene Bank].

In order to evaluate seed viability of Platycodon grandiflorum, Schizonepeta tenuifolia, Andrographis paniculat, Codonopsis pilosula, Scutellaria baicalensis, Leonurus japonicus, Rabdosia rubescens, stored in the medium-term gene bank of the National Medicinal Plant Gene Bank for 4 years, we tested seed germination rate of 7 species of medicinal plant and analyzed the change of significance of levels of the germination rate in pre and post store. Seed germination rates of 7 species of medicinal plants were all decreased after 4 years, and the decrease of S. tenuifolia and S. baicalensis germination rates were much smaller than other species. The higher initial germination rate of P. grandiflorum, C. pilosula, R. rubescens seed has the smaller decline of germination rate, but the data of A. paniculata showed the opposite trend. The rate decline of the germination of S. tenuifolia and S. baicalensis was roughly the same in different germination rate interval. The results showed that low temperature storage could effectively prolong the seed longevity, and maintain the seed vigor. Moreover, it is necessary to study on the storage characteristics of the main medicinal plant seeds, and establish the monitoring plan and regeneration standard.