马尾松HDR基因克隆及其对旱与盐胁迫的响应

干旱和土地盐渍化是制约林业可持续发展的重要因素,植物在遭受生物或非生物胁迫时,会在叶片释放萜类等挥发性物质。1-羟基-2-甲基-2-(E)-丁烯基-4-焦磷酸还原酶(HDR)是MEP途径的末端活性酶,具有提供前体萜类物质和主要限速作用。为探究马尾松HDR基因是否参与干旱和盐胁迫条件下的胁迫响应,该研究克隆了马尾松HDR基因开放阅读框,并初步分析了其生物信息、组织特异性表达水平和初步功能。结果表明:(1)PmHDR基因编码区长度为1 458 bp,编码485个氨基酸,其编码蛋白包含LytB/IspH基因超家族的核心序列和PLN02821多功能结构域,属于HDR家族。(2)PmHDR密码子使用偏好性较弱,偏好使用A/U结尾的密码子,烟草、拟南芥与酿酒酵母更适合作为其异源表达受体。(3)qRT-PCR结果显示,PmHDR基因在马尾松老叶中表达量最高,其次为幼叶、幼茎和老茎,在根中表达量最低。(4)构建基因表达载体pBI121-PmHDR并转化拟南芥,转基因拟南芥对干旱和盐胁迫表现出更强的抗逆性。以上研究结果表明PmHDR参与了植物干旱和盐胁迫的响应和调节,并为马尾松抗逆育种提供了一定的理论支持。     

Chemical,Antioxidant, and Antimicrobial Evaluation of Essential Oils and an Anatomical Study of the Aerial Parts from Baccharis Species (Asteraceae)

The aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC/MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORAC_FL) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only seven (β‐caryophyllene, γ‐muurolene, bicyclogermacrene, β‐germacrene, spathulenol, τ‐muurolol, and α‐cadinol) were common in the three specimens studied. Of these, γ‐muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORAC_FL (>500.0 μmol TE g^?1) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.     

Effect of esters based on terpenoids and GABA on fluidity of phospholipid membranes

Abstract

The influence of esters based on gamma-aminobutyric acid (GABA) and mono-/bicyclic terpenoids on membrane structure was investigated. The mechanism of action for terpenoid esters on phospholipids of artificial membranes and lipids isolated from the rat stratum corneum was studied by fluorescence and FT-IR spectroscopy. We report here, that inclusion of monocyclic terpenoid esters in phospholipid liposomes leads to growth of excimer to monomer ratio (I_E/I_M) indicating a decrease of membrane microviscosity. Another mechanism of influence on biomembranes was proposed for ester of bicyclic borneol - in this case a high ratio of vibronic peak intensities (I₁/I₃) was revealed. The addition of terpenoid esters appears in the FT-IR spectra as intensity reduction of absorption bands associated with C?=?O, P?=?O and P–O–С groups of lecithin phospholipids. Similar results were obtained after esters addition to lipids isolated from stratum corneum indicating a decrease of hydrogen bonds number between polar groups of lipids. Thus, the influence of terpenoid esters on molecular organization of the lipid matrix substantiates the feasibility of their use after transdermal delivery in vivo.     

Chemical Composition and In vitro Anthelmintic Activity of Extracts of Tagetes patula Against a Multidrug‐Resistant Isolate of Haemonchus contortus

Sheep breeding has suffered economic losses due to parasitism by gastrointestinal nematodes, particularly Haemonchus contortus. The use of natural products, specifically Tagetes patula, has been suggested as an alternative method of combatting this issue. Chemical analyses of the extracts of this species described in the literature report the presence of important classes of secondary metabolites such as thiophenes, flavonoids, alkaloids, and benzofurans, some of which were identified and isolated in this study. The aim of this work was to test the effect of the essential oil (EO) and the ethanolic extract of the aerial parts (Tp_EtOH) of T. patula on eggs and larvae of H. contortus, through an egg hatch test (EHT) and a larval development test (LDT). In the EHT, the EO showed 100% inhibition at 0.75 mg mL^?1 (LC₅₀ = 0.0780 mg mL^?1), and the Tp_EtOH showed 100% inhibition at 100 mg mL^?1 (LC₅₀ = 12.8 mg mL^?1). In the LDT, the EO showed 100% inhibition at 0.375 mg mL^?1 (LC₅₀ = 0.0400 mg mL^?1), and the Tp_EtOH showed 100% inhibition at 1.56 mg mL^?1 (LC₅₀ = 0.340 mg mL^?1). Compared to available literature data, the results presented here suggest that the crude extracts of T. patula have substantial potential for controlling this nematode by interrupting its life cycle and/or preventing it from reaching the infective stage.     

裂叶荆芥花穗腺鳞代谢规律研究

为揭示荆芥穗腺鳞在不同开花序列中数量性状及内含物的代谢规律,本实验通过对荆芥穗不同开花序列的萼片进行腺鳞密度及半径的测算,以腺鳞指数拟合评价其数量性状的动态变化;同时对不同开花序列腺鳞内含物中6种单萜类成分(β-月桂烯、d-柠檬烯、dl-薄荷酮、薄荷呋喃、胡薄荷酮、β-石竹烯)进行气相色谱检测与定量研究。结果显示:腺鳞的主要发生阶段为开花前期,并于开花期基本完成;荆芥穗开花后,腺鳞因受到外界因素的影响数量逐渐减少;以D10轮为界,腺鳞中对薄荷烷型单萜类成分的代谢过程存在明显的物候迭代规律,并致使胡薄荷酮在腺鳞内含物中蓄积。说明荆芥穗腺鳞于开花期基本完成其数量性状增长及内含物的合成,但薄荷酮、薄荷呋喃、β-石竹烯等化合物在开花后期仍处于旺盛代谢状态,并且其含量变化可直接造成荆芥穗药效性质的改变,因此D10轮可作为荆芥穗的采收节点。     

Seasonal variation of sexual differences in the volatile oil of Juniperus scopulorum

Very few differences between male and female trees were found in the volatile oil composition of Juniperus scopulorum Sarg. Differences were more apparent when the compounds were calculated as percent of total oil than as weight per g dry matter. Almost all of the sexual differences occurred in the growing season (March–May). Essentially no differences were observed during the rest of the year. The observed differences were very small and should not affect the choice of plant material used in revegetating efforts (when browse potential is important). These differences should not affect chemosystematic studies, particularly if sampling is done during the period of the year when the plants are dormant.     

Chemical variation in the tropical seaweed Stypopodium zonale (dictyotaceae)

Five separate collections of the tropical seaweed Stypopodium zonale were analysed for ten secondary metabolites using a combination of high performance liquid chromatography and proton nuclear magnetic resonance spectrometry. Shallow water populations from the Caribbean were found to possess similar metabolite profiles from year to year and from widely diverse locations. Stypopodium zonale from the South Pacific (Palau) contained similar structure types; however, the profile was qualitatively and quantitatively dissimilar to the Caribbean algae. A deep water Caribbean form of S. zonale was found to contain two metabolites, epitaondiol and 6a-desmethyl-6-acetylatomaric acid, not observed in the other extracts. This latter population is morphologically and anatomically distinct from the other S. zonale Caribbean populations.     

Terpenoids from Salvia palaestina

Six known terpenoids: vergatic acid, ursolic acid, crataegolic acid, lupane-3β-,11α, 20-triol, sclareol and sitosteryl 3β-glucoside were isolated from the leaves of Salvia palaestina and were identified by spectral data. Among the compounds, sclareol showed high activity against Staphylococcus aureus, S. epidermis, Escherichia coli, Proteus vulgaris and Pseudomonas aeruginosa, while the triterpenoids were not tested due to solubility problems.     

The use of metabolic profiling in the identification of gall mite (Cecidophyopsis ribis Westw.)-resistant blackcurrant (Ribes nigrum L.) genotypes

The terpenoid fractions of bud extracts from blackcurrant genotypes showing resistance or susceptibility to gall mite (Cecidophyopsis ribis) infestation were examined and compared using gas chromatography. By the use of discriminant analysis, and the application of the derived discriminator to the data, resistance status was correctly predicted in 88% of the genotypes sampled. The use of metabolic profiling provides a useful alternative to lengthy field assessments.     

Supercritical carbon dioxide extraction of selected medicinal plants--effects of high pressure and added ethanol on yield of extracted substances

The possibilities and limitations of supercritical fluid extraction of natural products of low, medium and high polarity under very high pressure and with polar modifiers has been investigated. The medicinal herbs marigold (Calendula officinalis), hawthorn (Crataegus sp.) and chamomile (Matricaria recutita) were used as models in this study. Extraction profiles and the spectra of extractable metabolites were recorded following extraction with mixtures of carbon dioxide:ethanol of varying proportions (0-20% ethanol) and at various pressures in the range 300-689 bar. Components were identified by HPLC-PAD-MS or GC-MS and quantified by HPLC or GC as appropriate. Extraction yields under the varying conditions depended to a large extent on the profiles of secondary metabolites present in the three drugs. Whereas the extractability of lipophilic compounds increased substantially at pressures above 300 bar, the yields of polyphenolic and glycosidic compounds remained low even at 689 bar and with 20% modifier in the extraction fluid.