杂交兰花瓣类黄酮成分分析及其对花色的影响

为探究杂交兰花色形成的物质基础,以7个杂交兰品种为研究材料,采用显色反应、紫外 可见光谱方法初步判断花瓣中色素的类型;利用超高效液相色谱串联质谱(UPLC MS/MS)技术分析黄色系品种‘玉凤’和红色系品种‘福韵红霞’中代谢物组分及其含量差异,为探索杂交兰花色形成机理和兰花育种提供理论依据。结果表明：(1)7个品种均含有黄酮类化合物,不含类胡萝卜素,除‘玉凤’和‘双艺雅凤’外均含有花青素。(2)在代谢物中检测到160种差异代谢物,显著富集在花青素生物合成途径与黄酮和黄酮醇生物合成途径。(3)矢车菊素衍生物和芍药素衍生物是红色系杂交兰‘福韵红霞’的主要花色素成分;槲皮素类衍生物是黄色系‘玉凤’的主要花色素成分,推测花青素和黄酮醇生物合成的分流是杂交兰花色变化的主要原因。     

杂交兰花色花香生物合成途径的转录组分析

该研究以杂交兰(Cymbidium hybrid)不同花色花香品种‘玉凤’(K18,黄色)和‘福韵丹霞’(K24,紫红色)为材料,采用RNA-Seq技术获得杂交兰不同花期的花朵转录组数据,分析杂交兰不同时期花色/花香相关基因的表达变化,探讨杂交兰花色花香形成的分子机理,为杂交的定向改良和新品种选育提供依据。结果表明:(1)K18和K24分别获得11914和6793个差异表达基因;KEGG注释显示,有58个差异基因与花色花香合成相关;进一步分析发现,类黄酮是K18和K24的主要花色素,其合成基因在小花蕾期显著上调,其中K18通过查尔酮异构酶基因(CHI)、类黄酮-3′,5′羟化酶基因(F3′5′H)和黄酮醇合酶基因(FLS)途径生成黄酮醇,K24则通过花青素合成酶基因(ANS)途径生成花青素。(2)qRT-PCR验证表明,萜类骨架基因羟甲基戊二酰辅酶基因(HMGS)、羟基-3-甲基戊二酰辅酶A还原酶基因(HMGR2)和甲羟戊酸-5-焦磷酸合酶基因(MVD)等的表达量均在K18盛花期最高,同时6个下游的萜烯合酶(TPS)基因在K18中表达量比K24上调100倍以上。(3)定量分析表明,K24、K18中的花色素苷总含量分别为608.74、122.28μg·g-1,K18花色苷含量仅为K24的20%;K24花中色素物质主要成分为矢车菊素苷,使其花色呈红色;K18中飞燕草素苷含量相对较高(花色为黄色)。研究推测,ANS基因的较高表达可能是K24花瓣中花色苷含量高于K18的原因之一,K18通过CHI、F3′5′H、FLS途径积累了大量黄酮醇而不是花青素,从而影响了花朵颜色的决定。     

烟草FLS基因表达抑制对类黄酮代谢的影响

高等植物中黄酮醇合成酶催化二氢黄酮醇转化生成黄酮醇,是类黄酮代谢途径的关键酶之一。本研究在烟草基因组数据库中搜索获得两个类黄酮合成酶基因,即NtFLS1和NtFLS2,二者表达模式一致,均在叶片中高水平表达。在NtFLS2基因过表达载体的转化株中获得一个共抑制株系KD36,荧光定量PCR分析表明NtFLS1和NtFLS2基因表达水平均被显著抑制,类黄酮途径其它结构基因的表达水平未发生显著变化。KD36株系中二氢槲皮素含量显著上升,是对照的12倍,槲皮素、山奈酚、二氢山奈酚含量未发生显著变化。KD36株系花色更红,花青素含量是对照植株2.4倍。上述研究揭示了烟草黄酮醇合成酶基因的功能,为进一步研究烟草类黄酮代谢提供了一定的理论依据。     

基于代谢组学的两种罗布麻叶片类黄酮和酚酸成分分析

目的：类黄酮和酚酸物质是罗布麻中主要的活性物质,鉴定不同罗布麻品种中类黄酮和酚酸代谢物成分并比较代谢物含量差异,为有效利用罗布麻属药用资源提供理论依据。方法：以罗布麻和大麻状罗布麻叶片为材料,利用液相色谱质谱联用技术（LC-MS）检测次级代谢物成分并进行分析。结果：2种罗布麻中共检测出275种类黄酮和194种酚酸物质;PCA分析表明2种罗布麻的代谢物种类相似,但含量存在较大差异,结合OPLS-DA筛选出124种显著差异代谢物,其中有80种类黄酮和44种酚酸;富集分析发现,共有10条代谢通路被显著富集,主要体现在苯丙烷生物合成、类黄酮生物合成以及黄酮和黄酮醇生物合成等途径。结论：2种罗布麻药用成分种类相似,可为大麻状罗布麻作为药用植物开发提供理论依据。     

莲属植物类黄酮代谢产物的研究进展

莲属(Nelumbo)植物既可药用也可食用, 其中荷叶、藕节、莲子、莲子心、莲房和莲须等皆可入药, 但药效各不相同。迄今为止, 从莲的各组织中共检测出类黄酮多达61个, 包括8个花青素苷、2个黄酮醇、29个黄酮醇苷、1个黄酮、16个黄酮苷(内含13个碳苷黄酮)和5个黄烷醇。该文对莲各组织中所含类黄酮的检测方法、组成、含量及药理等方面的研究进展进行了综述。迄今的研究结果表明, 莲中含有丰富的类黄酮化合物, 且具广泛的药理活性(如抗氧化、抗菌、抗HIV、抗动脉粥样化、提高免疫力和减肥降脂等)。这些资料不仅对今后深入研究莲各部位的类黄酮代谢物及其与药效的关系有重要意义, 而且对保健食品和中药的研发也具有重要的参考价值。     

外源脱落酸对桃果实着色及相关基因表达的影响

以‘美香’桃为试验材料,于果实着色前用1 000、500、300mg/L的脱落酸(ABA)溶液处理果实,研究了ABA处理促进桃果皮着色的效果以及对果皮花色素苷合成相关基因表达的影响。结果表明:ABA处理显著提高了成熟果实可溶性固形物含量和果皮花色素苷含量;明显改善了果实着色,且以1 000mg/L效果最为明显。ABA处理显著促进了查尔酮合成酶基因(CHS)和二氢黄酮醇4-还原酶基因(DFR)的前期转录水平,同时促进了类黄酮葡萄糖苷转移酶基因(UFGT)和花色素合成酶基因(LDOX)表达高峰的前移。据此推测ABA可能参与了桃果实花色素苷合成的调控,对花色素苷合成具有促进作用。     

遮阴对柠檬香茅类黄酮及其合成酶基因差异表达研究

为了解柠檬香茅(Cymbopogon citratu)中类黄酮及其合成酶基因信息,以阳光直射及遮阴环境下生长的柠檬香茅嫩叶为材料,进行代谢组、转录组结合qRT-PCR验证分析。结果表明,柠檬香茅中含有11类共69种黄酮化合物,其中芦丁、去甲基托罗沙黄酮、紫云英苷及葡萄糖醇等类黄酮化合物在遮阴环境下相对含量显著降低;类黄酮生物合成涉及10类酶54个基因,其中类黄酮3''羟化酶(c99177.1)等4个酶基因在遮阴环境下相对表达量显著降低,而异黄酮合成酶(c51975.0)等6个酶基因相对表达量正好相反;其中5个类黄酮合成酶基因在光照及遮阴柠檬香茅中的上下调表达趋势与转录组测序结果中FPKM值变化一致,而二者检测结果中差异表达倍数存在差异。遮阴使柠檬香茅中大多黄酮类化合物相对含量降低,而其合成酶基因上下调表达趋势规律不明显。     

操纵茶树类黄酮3′-羟基化酶生物合成B环-3′,4′-二羟基黄酮类化合物

【目的】操纵茶树类黄酮3′-羟基化酶,生物合成B环-3′,4′-二羟基黄酮类化合物圣草酚、二氢槲皮素和槲皮素。【方法】构建了4个茶树类黄酮3′-羟基化酶基因(CsF3′H)和拟南芥的P450还原酶基因(ATR)融合表达质粒:SUMO-CsF3'H[7-517]::ATR1[49-688]3 AA、SUMO-CsF3'H[28-517]::ATR1[49-688]3 AA、SUMO-CsF3'H[7-517]::ATR2[75-711]3 AA和SUMO-CsF3'H[28-517]::ATR2[75-711]3 AA,分别转化大肠杆菌菌株TOP10、DH5α和BL21,获得12个转化菌株S1–S12;构建了茶树类黄酮3′-羟基化酶基因CsF3′H表达质粒p YES-Dest52-CsF3′H,转化酵母菌株WAT11,得到转化菌株S13;构建了茶树类黄酮3′-羟基化酶基因CsF3′H表达质粒pES-URA-CsF3′H,及茶树黄烷酮3-羟基化酶基因CsF3H与拟南芥黄酮醇合成酶基因At FLS的融合表达质粒pES-HIS-CsF3H::At FLS 9AA,二者共转化酵母菌株WAT11,获得转化菌株S14。【结果】转化SUMO-CsF3'H[28-517]::ATR1[49-688]3 AA质粒的TOP10菌株S6在25°C条件下发酵,转化效率最高,能将1000μmol/L柚皮素、二氢山奈酚和山奈酚,分别转化生成287.93μmol/L圣草酚、131.76μmol/L二氢槲皮素和188.62μmol/L槲皮素。发酵菌株S13能分别将1000μmol/L柚皮素、二氢山奈酚和山奈酚,最多能转化生成734.32μmol/L圣草酚、446.07μmol/L二氢槲皮素和594.64μmol/L槲皮素。喂食S14发酵菌株5 mmol/L的底物柚皮素,在发酵36–48 h中,最多能生成1412.16μmol/L圣草酚、490.25μmol/L山奈酚、445.75μmol/L槲皮素、66.75μmol/L二氢槲皮素和73.50μmol/L二氢山奈酚。【结论】本研究首次将茶树类黄酮3′-羟基化酶基因应用于B环-3′,4′-二羟基黄酮类化合物圣草酚、二氢槲皮素和槲皮素的生物合成。     

小苍兰花色色素成分及稳定性分析

以小苍兰(Freesia refracta)16个不同花色品种及后代为试验材料,对花瓣色素用特征显色反应和紫外-可见光谱扫描,分析其色素的成分和花色素苷的稳定性.结果表明,小苍兰花色的色素属于类黄酮化合物,含黄酮和花色素苷类物质,可能含有异黄酮,不含黄酮醇、二氢黄酮、二氢黄酮醇、查耳酮和橙酮,其中黄色系品种及后代还含有类胡萝卜素.避光下小苍兰花色素苷的稳定性要强于光照;温度对花瓣色素的稳定性有一定的影响.     

花青素生物合成关键酶的研究进展

花青素是植物花呈现不同色彩的物质基础,其生物合成途径主要受到查尔酮合成酶(CHS)、查尔酮异构酶(CHI)、黄烷酮3-羟化酶(F3H)、类黄酮3'-羟化酶(F3'H)、类黄酮3’,5’-羟化酶(F3'5'H)、二羟基黄酮醇还原酶(DFR)、花色素苷合成酶(ANS)以及类黄酮3-O-糖基转移酶(UFGT)等关键酶的控制.主要介绍花青苷生物合成途径、关键酶晶体结构及利用基因工程改造花色的研究进展,讨论目前花色改造存在的问题,并对今后的研究前景进行展望.     

Y-chromosome Data and Tribal Affiliations of Allenopithecus and Miopithecus

The phylogeny of Old World monkeys has remained unresolved in part because of a lack of resolution in the Cercopithecinae. Competing morphological hypotheses have had Allen's swamp monkey (Allenopithecus nigroviridis) and the talapoins (Miopithecus spp.) as basal branches of either the tribe Cercopithecini or the tribe Papionini. Previous molecular analyses have not adequately addressed the issue. To better understand the evolutionary history of these primates, we sequenced and subjected to phylogenetic analysis 3.1 kb of 2 loci (TSPY and SRY) from the non-recombining portion of the Y-chromosome. Individuals from the genera Allenopithecus, Miopithecus, Erythrocebus, Chlorocebus, and Cercopithecus were surveyed and their sequences compared with those previously published for the Papionini and Colobinae. The results suggest Allenopithecus and Miopithecus are more closely related to the Cercopithecini than Papionini. Our data also support the hypothesis that within the Cercopithecini, Erythrocebus and Chlorocebus share a close evolutionary relationship, distinct from the other members of the tribe.     

Ovule and seed anatomy ofCistaceae and relatedMalvanae

Ovule and especially seed anatomy of eight species ofCochlospermaceae, Bixaceae, Cistaceae, Monotoideae, Pakaraimaeoideae (two subfamilies ofDipterocarpaceae), andSarcolaenaceae were investigated. All representatives show a bixoid chalazal region in the seed as probable exclusive synapomorphy among angiosperms. The palisade layer of the exotegmen is curved inwards at its proximal end and forms a dome-shaped structure. A plug of hypostase tissue with an annulus/core structure fits into this dome. Moreover, two additional tissue types in the hypostase can be found in some representatives of the group. These and other micromorphological, wood anatomical, and floral morphological characters, indicate that the taxa form a monophyletic group close toMalvales s. str. The form of the starch grains in the endosperm is compared and is described for the first time forPakaraimaea (Dipterocarpaceae) andLeptolaena (Sarcolaenaceae). The position ofDiegodendron close toBixa and the presumably more distant positions ofMuntingia andNeuradaceae are discussed.     

Nystatin and killer toxin sensitivity of free and immobilizedSaccharomyces cerevisiae

The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.     

Amino acids and sugars in nectar,and their putative evolutionary significance

Individual amino acids and sugars from flower nectar of 32 plant species with different pollination systems were quantified and compared. Data show that there is no correlation between sugar and amino acid concentration. Furthermore there is no correlation between composition and concentration of amino acids and evolutionary advancement, nor any direct relation with pollination systems. However, higher sugar concentrations are often linked with more advanced morphological characters. Nectars from pierced or damaged flowers or nectars contaminated with pollen exhibit modifications and increases in amino acid composition. The presence of proline probably indicates such pollen contamination. Most pollinating animals depend on flower nectar in their energetic requirements, yet innumerable alternative amino acid and protein sources exist. Future research has to consider the relationship between nutritional requirements of pollinating animals and dependence on flower nectars.Dedicated to Prof. Dr.L. van der Pijl, Den Haag, in honour of his 80th birthday.     

The hernandez and fernandez genes of Drosophila specify eye and antenna

The formation of different structures in Drosophila depends on the combined activities of selector genes and signaling pathways. For instance, the antenna requires the selector gene homothorax, which distinguishes between the leg and the antenna and can specify distal antenna if expressed ectopically. Similarly, the eye is formed by a group of "eye-specifying" genes, among them eyeless, which can direct eye development ectopically. We report here the characterization of the hernandez and fernandez genes, expressed in the antennal and eye primordia of the eye-antenna imaginal disc. The predicted proteins encoded by these two genes have 27% common amino acids and include a Pipsqueak domain. Reduced expression of either hernandez or fernandez mildly affects antenna and eye development, while the inactivation of both genes partially transforms distal antenna into leg. Ectopic expression of either of the two genes results in two different phenotypes: it can form distal antenna, activating genes like homothorax, spineless, and spalt, and it can promote eye development and activates eyeless. Reciprocally, eyeless can induce hernandez and fernandez expression, and homothorax and spineless can activate both hernandez and fernandez when ectopically expressed. The formation of eye by these genes seems to require Notch signaling, since the induction of ectopic eyes and the activation of eyeless by the hernandez gene are suppressed when the Notch function is compromised. Our results show that the hernandez and fernandez genes are required for antennal and eye development and are also able to specify eye or antenna ectopically.     

Cyclooxygenase inhibitory and antioxidant cyanidin glycosides in cherries and berries

Anthocyanins from tart cherries, Prunus cerasus L. (Rosaceae) cv. Balaton and Montmorency; sweet cherries, Prunus avium L. (Rosaceae); bilberries, Vaccinum myrtillus L. (Ericaceae); blackberries, Rubus sp. (Rosaceae); blueberries var. Jersey, Vaccinium corymbosum L. (Ericaceae); cranberries var. Early Black, Vaccinium macrocarpon Ait. (Ericaceae); elderberries, Sambucus canadensis (Caprifoliaceae); raspberries, Rubus idaeus (Rosaceae); and strawberries var. Honeoye, Fragaria x ananassa Duch. (Rosaceae), were investigated for cyclooxygenase inhibitory and antioxidant activities. The presence and levels of cyanidin-3-glucosylrutinoside 1 and cyanidin-3-rutinoside 2 were determined in the fruits using HPLC. The antioxidant activity of anthocyanins from cherries was comparable to the commercial antioxidants, tert-butylhydroquinone, butylated hydroxytoluene and butylated hydroxyanisole, and superior to vitamin E, at a test concentration of 125 microg/ml. Anthocyanins from raspberries and sweet cherries demonstrated 45% and 47% cyclooxygenase-I and cyclooxygenase-II inhibitory activities, respectively, when assayed at 125 microg/ml. The cyclooxygenase inhibitory activities of anthocyanins from these fruits were comparable to those of ibuprofen and naproxen at 10 microM concentrations. Anthocyanins 1 and 2 are present in both cherries and raspberry. The yields of pure anthocyanins 1 and 2 in 100 g Balaton and Montmorency tart cherries, sweet cherries and raspberries were 21, 16.5; 11, 5; 4.95, 21; and 4.65, 13.5 mg, respectively. Fresh blackberries and strawberries contained only anthocyanin 2 in yields of 24 and 22.5 mg/100 g, respectively. Anthocyanins 1 and 2 were not found in bilberries, blueberries, cranberries or elderberries.     

Pollen morphology ofSonchus and related genera,and a general discussion

The pollen morphology of the taxa belonging to the generaAetheorhiza Cass.,Launaea Cass.,Reichardia Roth andSonchus L. in the Iberian Peninsula has been studied with light and electron microscopy. The pollen is 3(-4)-zonocolporate and echinolophate (without polar lacunae, but in general with prelacunae), with equatorial ridges and 15–20 lacunae: 3–4 poral, 6–8 abporal and 6–8 paraporal. Small to medium size, P × E = 19–36 × 23–42 µm; sometimes two different sizes have been found. Exine 3–9 µm thick and ornamentation microreticulate and echinate. The results clearly show the relationships between genera. Moreno-Socías, E., Mejías, J. A., Díez, M. J., 1994: Morfología polínica deLactuceae (Asteraceae) en la Península Ibérica, I.Lactuca y géneros relacionados. — Acta Bot. Malacitana.19: 103–113.     

Utilized and potentially utilizable seaweeds on the Namibian coast: biogeography and accessibility

Of the 1500 km coast of Namibia, only 80 km is predominantly rocky, the remaining 1420 km being sandy with only minor rocky outcrops. At present two species are utilized, Gracilaria verrucosa for agar and Laminaria schinzii for human consumption. Other potentially utilizable seaweeds occurring on the coast are Ecklonia maxima for alginates, Suhria vittata for agar, Gigartina radula, G. stiriata and Aeodes orbitosa for carrageenans and Porphyra capensis for human consumption. Laminaria schinzii also can be used for alginate production. Due to the diamond-mining areas around the 80 km rocky area at Luderitz (26° 39 S), only 20 km are accessible; hence, at present the seaweeds are being exploited almost to their full potential. The species currently not being utilized could be used, however, to support the industry that already exists at Luderitz. To increase production, access to the diamond areas would have to be gained or a cultivation program initiated.     

Molecular identification and differentiation of Brevibacterium species and strains

Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of Brevibacterium linens, Brevibacterium casei and Brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ARDRA was applied to the 16S rDNA. B. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences. AccI gave genus specific restriction patterns and was used to separate Brevibacterium from Corynebacterium species. The expected species specificity of TaqI applied to B. linens type culture strains, but not to all strains isolated from cheese. By AvaI restriction, B. casei and B. linens were differentiated from B. epidermidis and the orange pigmented Arthrobacter casei, a new species of coryneform bacteria; by XmnI restriction, B. linens and B. epidermidis were differentiated from B. casei. One of 4 B. linens genotypes could not be distinguished from B. casei by this method. Here, the typical orange B. linens pigments were used for classification, which was confirmed by partial sequencing of the 16S rDNA.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.