Hydrangea mosaic virus, a new ilarvirus from Hydrangea macrophylla (Saxifragaceae)

A previously unrecognised virus isolated from Hydrangea macrophylla with chlorotic mosaic leaf symptoms in West Sussex was named hydrangea mosaic virus (HydMV). HydMV was mechanically transmitted without difficulty to four of 16 species from three of five families, and was seed transmitted in Chenopodium quinoa, but was not aphid transmitted. Although relatively unstable in vitro, HydMV was purified by clarifying leaf extracts by emulsification with chloroform and acidification with citric acid, followed by differential centrifugation and sucrose density gradient centrifugation. Purified virus incompletely separated on sucrose density gradients into three components (T. M and B) with sedimentation coefficients (s^o_20w) of 86, 97, and 105 S respectively, but all particles had buoyant densities in caesium chloride of 1.37 g/cm³. Virus contained a single polypeptide species (mol. wt 26.4 times 10³), appeared quasiisometric to ovoid or elliptical, and measured c. 28 times 30 (T), 30 times 30 (M) or 30 times 32–38 nm (B). Single-stranded RNA species or mol. wt 1–25, 1–08, 0–83, 0–36 and 0–27 (RNA-1 to 5 respectively) were obtained from virus preparations but mixtures containing RNA-1 to 3 plus either RNA-4 + 5 or the coat protein, were infective. These properties suggest that HydMV has affinities with ilarviruses, but it showed no serological relationship to any of six ilarviruses or 42 other viruses.     

八仙花离体培养和植株再生

1 植物名称八仙花(Hydrangea macrophylla). 　　2 材料类别带腋芽茎段、顶芽. 　　3 培养条件诱导培养基:(1)MS 6-BA 0.5 mg*L-1(单位下同) NAA 0.01 3%蔗糖.增殖培养基:(2)MS 6-BA 2.0 NAA 0.1 3%蔗糖.瓶内生根培养基:(3)1/2MS NAA 0.1 1.5%蔗糖.上述培养基均附加0.7%琼脂,pH 5.8～6.0.瓶外生根基质:(4)珍珠岩∶蛭石＝1∶1.培养温度23～27℃,光照时间12 h*d-1,光照度1 500～2 000 lx.……     

p-Coumaroyltriacetic acid synthase, a new homologue of chalcone synthase, from Hydrangea macrophylla var. thunbergii.

Chalcone synthase and stilbene synthase are plant-specific polyketide synthases. They catalyze three common consecutive decarboxylative condensations and specific cyclization reactions. They are highly homologous to each other, and are likely to fall into a family of polyketide synthases along with acridone synthase and bibenzyl synthase. Two cDNA clones (named HmC and HmS), both of which show high homology to the known chalcone synthases, were obtained from leaves of Hydrangea macrophylla var. thunbergii. They were expressed in Escherichia coli in order to determine their enzyme functions. Detection of chalcone formation clearly indicated that HmC encoded chalcone synthase, while HmS protein catalyzed the formation of neither chalcone nor stilbene. However, a novel pyrone, a lactonization product of a linear tetraketide was detected in reaction products of HmS protein. This proves that HmS encodes a novel polyketide synthase that catalyzes only chain elongation without cyclization.     

Three secoiridoid glucosides from Ligustrum japonicum

Three new secoiridoid glucosides, ligustaloside A, ligustaloside B and 10-hydroxyoleuropein, along with two known glucosides, oleuropein and ligstrosid     

Metabolism of phenylpropanoids in Hydrangea serrata var. thunbergii and the biosynthesis of phyllodulcin

DL-Phenylalanine-[3-¹⁴C] and cinnamic acid-[3-¹⁴C] were fed to this plant and the label from cinnamic acid was incorporated into gallic acid, phyllodulcin and quercetin. By feeding p- coumaric acid-[U-³H], caffeic acid-[U-³H] and hydrangea glucoside A-[U-³H], it was possible to show that hydroxylation at C-3′in phyllodulcin occurs after the ring closure of dihydroisocoumarin. The biosynthetic pathway of phyllodulcin in this plant is thus: phenylalanine → cinnamic acid → p- coumaric acid → hydrangenol → phyllodulcin.     

Three new secoiridoid glucosides from Eustoma russellianum

Three new secoiridoid glucosides, eustomoside, eustoside and eustomorusside, have been isolated along with three known glucosides, sweroside, swertiamarin and gentiopicroside, as well as one unknown glycoside from Eustoma russellianum.     

Evaluation of Hydrangea macrophylla for Resistance to Leaf‐Spot Diseases

Garden hydrangea (Hydrangea macrophylla) is a popular ornamental plant that can be devastated by leaf‐spot diseases. Information is needed to determine susceptibility of commercial cultivars to leaf‐spot diseases. To address this need, 88 cultivars of H. macrophylla were evaluated for their resistance to leaf‐spot diseases in full‐shade (2007–2008), full‐sun (2007–2008) and partial‐shade (2009–2010) environments in McMinnville, TN, USA. Ten cultivars [‘Ami Pasquier’, ‘Ayesha’, ‘Blue Bird’, ‘Forever Pink’, ‘Fuji Waterfall’ (‘Fujinotaki’), ‘Miyama‐yae‐Murasaki’, ‘Seafoam’, ‘Taube’, ‘Tricolor’ and ‘Veitchii’] were rated resistant (R) or moderately resistant to leaf spot under each of the three environments. In 2007–2008, approximately 51% of the cultivars were rated R in full shade, but only 5% were R in full sun. In 2009–2010, only 1% of the cultivars were rated R in partial shade. Although environmental parameters including temperature and rainfall influence disease severity and host reaction, a shaded environment was least favourable for leaf‐spot disease development, which demonstrates that establishing hydrangea in shaded environment can be an effective tool along with cultivar selection for managing leaf‐spot diseases on hydrangea. Six pathogens, Corynespora cassiicola, Cercospora spp., Myrothecium roridum, Glomerella cingulata (Anamorph: Colletotrichum gloeosporioides), Phoma exigua and Botrytis cinerea, were associated with leaf‐spot diseases of garden hydrangea. Of the leaf‐spot pathogens, C. cassiicola was most frequently isolated (55% of all isolates), followed by Cercospora spp. (20%) and other pathogens (25%). Because symptoms attributed to each leaf‐spot pathogen were similar, cultivars were selected for resistance to multiple leaf‐spot pathogens.     

绣球抗旱性综合评价及指标体系构建

采用盆栽持续干旱处理,测定5个耐旱能力不同的绣球品种生根苗25项生理生化指标,研究各品种绣球的抗旱性强弱,构建绣球品种抗旱性评价体系.结果表明: 干旱胁迫20 d后,绣球的比叶质量、细胞膜透性、丙二醛含量、超氧化物歧化酶活性、可溶性糖含量、脯氨酸含量、胞间CO₂浓度和非光化学猝灭系数均显著升高,而叶片相对含水量、净光合速率、气孔导度、蒸腾速率、光系统Ⅱ实际光量子产量和电子传递速率均显著降低.主成分分析将25项生理生化指标转化为3个互相独立的综合指标(累计贡献率达87.1%),主成分1主要反映光合、荧光等信息,主成分2主要反映植株活力等信息,主成分3主要反映膜系统及渗透调节系统等信息.聚类分析将5个绣球品种划分为3个类型:拉维布兰和塔贝为耐旱型品种,你我的浪漫为中间型品种,无尽夏新娘和银边为不耐旱型品种.根据绣球品种抗旱性综合评价值D,5个品种的抗旱性排序为拉维布兰>塔贝>你我的浪漫>无尽夏新娘>银边.细胞膜透性、过氧化物酶活性、可溶性蛋白含量和电子传递速率4个指标对绣球抗旱性有显著影响,可简化绣球抗旱性鉴定工作.     

New type of anti-diabetic compounds from the processed leaves of Hydrangea macrophylla var. thunbergii (Hydrangeae Dulcis Folium)

Two 3-phenyldihydroisocoumarins (hydrangenol and phyllodulcin), a 3-phenylisocoumarin (thunberginol A), and a stilbene (hydrangeaic acid) from the processed leaves of Hydrangea macrophylla var. thunbergii (Hydrangeae Dulcis Folium) promoted adipogenesis of 3T3-L1 cells. Hydrangenol, a principal constituent, significantly increased the amount of adiponectin released into the medium and mRNA levels of adiponectin, peroxisome proliferator-activated receptor gamma2 (PPARgamma2), and glucose transporter 4 (GLUT4), while it decreased the expression of interleukin 6 (IL-6) mRNA. Furthermore, hydrangenol significantly lowered blood glucose and free fatty acid levels 2 weeks after its administration at a dose of 200 mg/kg/d in KK-A(y) mice.     

Polyphenol Components in Cultured Cells of Amacha (Hydrangea macrophylla Seringe var. Thunbergii Makino)

In the course of our studies on the polyphenol components of the cultured cells of amacha, seven polyphenol compounds were isolated as pure crystals. The chemical structures of these compounds were determined by analytical methods (IR, UV, NMR and MS spectra) and colour reactions, and the compounds were identified as phyllodulcin, hydrangenol, daphnetin-8-monomethylether, umbelliferone, phyllodulcin-8-β-D-glucoside, hydrangenol-8-β-D-glucoside and skiminin (umbelliferone-7-β-D-glucoside). This is the first report of the isolation of phyllodulcin-8-β-D-glucoside and daphnetin-8-monomethylether from a natural source and of the other compounds from the cells of higher plants in suspension culture.     

Purification and characterization of an ethylene-induced antifungal protein from leaves of guilder rose (Hydrangea macrophylla).

An ethylene-induced, chitin-binding protein (designated as HM30) from leaves of Hydrangea macrophylla was identified and purified to apparent homogeneity by chitin affinity chromatography followed by FPLC on a Superose 12 column. The molecular mass of HM30 was 30,010.0 Da determined by mass spectrometry and its isoelectric point of 8.4 was estimated by isoelectric focusing. The amino acid composition of HM30 was also determined. The initial 15 amino acid residues of the N-terminal were found to be N-S-M-E-R-V-E-E-L-R-K-K-L-Q-D by automatic Edman degradation. This chitin-binding protein showed antifungal activity toward several crop fungal pathogens. Knowledge of properties of HM30 should be useful for its potential application as a plant fungicidal agent.     

Isolation and Identification of Hydrangenol and Umbelliferone from Cultured Cells of Amacha (Hydrangea macrophylla Seringe var. Thunbergii Makino)

2-[1-(1-Alkylamino)alkylidene]- 1,3-dicarbonyl compounds were synthesized as photosynthetic electron transport (PET) inhibitors because of their structural resemblance to the potent new PET inhibitors “cyanoacrylates”. Their functionalities were different from those of other classic photosystem II (PS II) inhibitors, and these compounds inhibited PET at the reducing side of PS II. In this paper, the synthetic approaches to these compounds are discussed.     

Xanthone and dihydroisocoumarin from Montrouziera sphaeroidea

A xanthone, montrouxanthone and a dihydroisocoumarin, montroumarin were isolated from the stem bark of Montrouziera sphaeroidea Pancher Ex Planchon et Triana [Guttiferae], along with two known compounds. Their structures were elucidated on the basis of spectroscopic analyses. This is the first report of the analysis of chemical constituents of Montrouziera species.     

Three new dinormonoterpenoid glucosides from pericarps of Myriopteron extensum

Three new dinormonoterpenoid glucosides, rel-(3R,4R)-3-(1-hydroxypropan-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (1), rel-(3R,4S)-3-(1-hydroxypropan-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (2), and rel-(3R,4S)-3-(1-hydroxy-2-propen-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (3), were isolated from the edible pericarps of Myriopteron extensum (Wight & Arn.) K. Schum. (Asclepiadaceae). Their structures were elucidated by chemical and spectroscopic methods including HRESIMS, 1D and 2D NMR. Dinormonoterpenoid glucosides were reported from Asclepiadaceae for the first time. Compounds 1–3 were evaluated for their cytotoxicity against five human cancer cell lines HL-60, SMMC-7221, A-549, MCF-7, and SW-480, but they did not exhibit cytotoxicity on the tested cell lines.     

Sepal color variation of Hydrangea macrophylla and vacuolar pH measured with a proton-selective microelectrode

Sepal color of hydrangea varies with the environmental conditions. Although chemical and biological studies on this color variation have a long history, little correct knowledge has been generated about color development. All colored sepals contain the same anthocyanin, delphinidin 3-glucoside. Thus, there must be some other system for developing the wide variety of colors. In hydrangea sepals the cells of the epidermis are colorless and only the second layer of cells contain pigment. We prepared protoplasts without any color change during enzyme treatment of sepals and measured the vacuolar pH of each of the colored cells. We could correlate the color of a single hydrangea cell with its vacuolar pH using a combination of micro-spectrophotometry and a proton-selective microelectrode. Values for the vacuolar pH of blue (lambda vismax: 589 nm) and red cells (lambda vismax: 537 nm) were 4.1 and 3.3, respectively, the vacuolar pH of blue cells being significantly higher.     

Three new neolignan glucosides from the stems of Dendrobium aurantiacum var. denneanum

Three new neolignan glucosides (1–3), together with four known analogs (4–7), have been isolated from the stems of Dendrobium aurantiacum var. denneanum. Structures of the new compounds including the absolute configurations were determined by spectroscopic and chemical methods as (−)-(8R,7′E)-4-hydroxy-3,3′,5,5′-tetramethoxy-8,4′-oxyneolign-7′-ene-9,9′-diol 4,9-bis-O-β-d-glucopyranoside (1), (−)-(8S,7′E)-4-hydroxy-3,3′,5,5′-tetramethoxy-8,4′-oxyneolign-7′-ene-9,9′-diol 4,9-bis-O-β-d-glucopyranoside (2), and (−)-(8R,7′E)-4-hydroxy-3,3′,5,5′,9′-pentamethoxy-8,4′-oxyneolign-7′-ene-9-ol 4,9-bis-O-β-d-glucopyranoside (3), respectively.     

Effects of shading on photosynthetic characteristics and chlorophyll fluorescence parameters in leaves of Hydrangea macrophylla

Aims The objectives were to investigate the effects of different light intensities on photosynthetic characteristics and chlorophyll fluorescence parameters, to clarify the physiological responses and photo-protective mechanisms of Hydrangea macrophylla to changes in light regimes in view of the distribution of energy absorbed and photosynthetic characteristics.Methods Three light regimes including natural and shade (shading rate 50% and 75% of natural light) were applied to plants for 60 days. After the treatment, the gas-exchange, chlorophyll a fluorescence and photosynthesis-light curves were measured by a portable leaf gas exchange system (LI-6400).Important findings The results showed that the weak light intensity treatment reduced dark respiration rate, light compensation point and light saturation point of plant, but increased apparent quantum yield, suggesting that plants had the physiological strategy to utilize the weakening light by reducing respiration. The net photosynthetic rate, intercellular CO₂ concentration, transpiration rate and water use efficiency of plants grown below 50% of natural light showed significant difference compared with natural and shading rate 75% of natural light. There were significant difference between natural and shade treatments in the maximal quantum efficiency of PSII (F_v/F_m), as indicated that it was significantly less at full light than that at 50% of natural light. Initial fluorescence intensity (F_o) of plants was higher at full light than that at 50% of natural light, suggesting that photoinhibition occurred in natural light. The non-photochemical quenching (NQP) decreased with the aggravation of shade stress, indicating that shading decreased the efficiency of photochemical reaction by reducing the fraction of incident light in photochemical energy utilization and decreased thermal dissipation through regulating energy distribution in photosystem II (PSII) in the leaves of Hydrangea macrophylla. In general, the 70% of incident light in photochemical energy utilization was distributed to thermal dissipation, 20% was distributed to non-regulated energy dissipation and 4% was distributed to effective photochemical reaction. In conclusion, responses of plants to increased irradiance are governed by strategy: to utilize a high fraction of incident light in photochemistry and regulate energy dissipation in PSII and weaken the accumulation of excess excitation energy in PSII to protect the photosynthetic apparatus in the leaves of H. macrophylla under saturated radiation.