茶树花青素形成分子机理的研究进展

花青素是由类黄酮合成途径产生的次生代谢产物,含量高时会使茶树新梢呈现红色或紫色。同时,花青素相比儿茶素等具有更明显的抗氧化、预防肿瘤等药理保健作用。文章就茶树花青素合成途径、转录及转录后调控等方面进行综述,以期更好地为高花青素茶树的育种研究提供理论依据。     

葡萄果皮花青素提取工艺优化研究

利用高效液相色谱(HPLC)对提取葡萄果皮中花青素的提取液、提取方法和色谱条件进行比较,采用正交实验设计选择最佳的提取工艺,利用5种花青素峰面积分析夏黑葡萄果皮所含花青素的含量。试验结果表明,提取液为甲醇：水=1:1,磷酸调pH=2.0,提取时超声辅助提取30min,为最佳的工艺提取出夏黑葡萄果皮中花青素的含量,色谱条件为流动相A：水/乙腈/甲酸= 40/50/10(v/v/v),流动相B：水/乙腈/甲酸= 87/3/10(v/v/v),柱温45℃,进样量20μL,检测波长520 nm,梯度洗脱条件为:(1)0-15 min,6% A-30% A；(2)15-30 min,30% A-50% A；(3)30-35 min,50% A-60% A；(4)35-40 min,60% A-6% A,呈现的色谱图分离度更好,总体效果更佳。     

光对园艺植物花青素生物合成的调控作用

花青素是植物中一类重要的类黄酮化合物,在植物花朵、果实等器官色泽形成和抗氧化过程中起着重要作用。植物组织中花青素的形成依赖于光信号,但是光信号对花青素生物合成的调控机制及信号网络很大程度上还不清晰。本文简述了花青素生物合成及运转过程的研究进展,简要归纳了MYB、bHLH、WDR三类主要因子对花青素合成的转录调控作用,重点阐释光信号（光强、光质、光照时长）对植物花青素合成的调控作用。研究表明,光环境（光强、光质、光照时长）主要通过不同的光受体（UVR8、CRYs、PHOTs、PHYs）影响光信号通路重要因子COP1的泛素化能力和HY5的稳定性,以及其他光信号转录因子如光敏色素互作因子PIFs的稳定性,进而调控花青素的生物合成过程。这些光信号因子一方面直接结合到调控花青素合成的MYB、bHLH、WDR三大类转录因子上,转录激活或抑制它们的表达进而调控花青素的合成;另一方面,这些光信号因子通过与MYB、bHLH、WDR三大类转录因子蛋白互作,影响它们形成的MBW复合体稳定性,进而调控花青素的合成。此外,这些光信号因子还可以通过不依赖于MBW复合体的通路调控花青素的合成,如HY5通过调控miR858影响花青素的生物合成;另外,一些未知的光响应因子可能以不依赖MBW通路的方式直接或间接地调控花青素合成基因和液泡膜上的运转蛋白,改变液泡酸化,调节花青素的合成。同时,光信号会影响光合电子传递,光合电子传递链中的一些因子也会通过依赖和不依赖MBW的途径影响植物花青素的合成。这些途径如何协调以及哪些信号因子优先受光环境（光强、光质、光照时间）调控?本文为深入研究光信号对花青素生物合成的调控机理提供参考,以探索光调控花青素积累的有效途径及靶标分子,为利用基因工程、代谢工程和光环境调控手段改良园艺植物花青素积累提供理论基础。     

荔枝果皮花色苷生物合成及调控机理研究进展

荔枝是无患子科荔枝属的亚热带常绿果树,具有很高的商业价值。荔枝果皮色泽由多种色素决定,是影响消费者需求的重要品质性状。果实着色是花色苷积累的结果,荔枝果皮花色苷的生物合成是一个复杂的过程,主要由遗传背景决定,同时受内外环境影响。本文重点介绍荔枝果皮花色苷的生物合成途径,从外界环境、生理生化以及分子生物学等方面,对花色苷积累的调控机制进行综述,并展望该领域的研究方向,为提升荔枝果实的色泽品质提供重要参考。     

The association of genes for purple coleoptile with chromosomes of the wheat variety Mironovskaya 808

Summary The association of genes for purple pigment in the coleoptile with the chromosomes of the winter wheat variety Mironovskaya 808 was investigated using monosomic F₂ analysis. The segregation ratio for F₂ hybrids of Chinese Spring monosomics x Mironovskya 808 seems to indicate that the purple colour of the coleoptile is determined by two dominant genes, Rc₃ and Rc₄, which are located on the chromosomes 7D and 6B respectively, and which reinforce each other. Apart from these two genes, suppressors found on the chromosomes 2A, 2B, 2D, 4B and 6A also play a role in the intensity of the purple colour.With the aid of a Chinese Spring telocentric chromosome marker it was observed that the Rc₃ gene is located on the chromosome arm 7DS, at a distance of 16±4.23 crossover units from the centromere.     

Genetic characterization of banana cultivars (Musa spp.) from Brazil using microsatellite markers

Flavonoids, in particular the anthocyanins,are responsible for flower colour in manyspecies. The dihydroflavonols represent abranch point in flavonoid biosynthesis,being the intermediates for production ofboth the coloured anthocyanins, through theaction of the enzyme dihydroflavonol4-reductase (DFR), and the colourlessflavonols, produced by flavonol synthase(FLS). In this study the white-flowered,flavonol accumulating Mitchell line ofpetunia was used as a model to examine theinteraction between DFR and FLS enzymeactivities and possibilities forredirecting flavonoid biosynthesis awayfrom production of flavonols and towardsanthocyanins. Introduction of a 35SCaMV-DFR sense transgene construct causedthe production of anthocyanins, resultingin a pink-flowered phenotype. Furthermore,inhibition of FLS production throughintroduction of an FLS antisense RNAconstruct also led to anthocyaninproduction and a pink-flowered phenotype. A combination of both transgenes gave thehighest level of anthocyanin formation. Anthocyanins were produced in the DFR-senseand FLS-antisense transgenic lines in spiteof the greatly reduced levels of geneexpression in the Mitchell line for threeenzymes late in anthocyanin biosynthesis,anthocyanindin synthase, UDP-glucose:flavonoid 3-O-glucosyltransferase andUDP-rhamnose: anthocyanidin-3-glucosiderhamnosyltransferase. Thus, the level ofgene activity required for visibleanthocyanin formation is much lower thanthe high levels normally induced duringpetal development. Altering the balancebetween the DFR and FLS enzyme activities,using genetic modification, may be a usefulstrategy for introducing or increasinganthocyanin production in target ornamentalspecies.     

New types of major anthocyanins detected in Japanese garden iris and its wild forms

The anthocyanins of 130 cultivars, 13 lines and 3 wild forms of Iris ensata were analyzed by HPLC, and these plants were classified into 16 types of major anthocyanins. Among these types, 8 types such as petunidin 3RGac5G – delphinidin 3RGac5G, delphinidin 3RGac5G – petunidin 3RGac5G, cyanidin 3RGac5G – peonidin 3RGac5G, delphinidin 3RG – delphinidin 3RGac, petunidin 3RG5G – malvidin 3RG5G, malvidin 3RG5G – peonidin 3RG5G, peonidin 3RG5G – cyanidin 3RG5G and peonidin 3RG – cyanidin 3RG were obtained as new types. In these new types, peonidin 3RG – cyanidin 3RG and peonidin 3RG5G – cyanidin 3RG5G types were noteworthy because cyanidin 3RG and cyanidin 3RG5G are useful for the breeding of red flowers in I. ensata. This revised version was published online in July 2006 with corrections to the Cover Date.     

An HPLC investigation of flower colour and breeding of anthocyanins in species and hybrids of Alstroemeria

The tepals of 28 Chilean species of Alstroemeria and 183 interspecific hybrids were analysed for anthocyanin content by high-performance liquid chromatography (HPLC). The anthocyanins were identified as 3-rutinosides of 6-hydroxydelphinidin, 6-hydroxyeyanidin, cyanidin, and delphinidin and 3-glyeosides of cyanidin and delphinidin, some of which were acylated with malonic acid. Comparisons of the anthocyanin contents in parents and offspring showed that no anthocyanidin or acylation pattern was dominant, and that offspring values were close to mid-parent values for the percentage of malonated anthocyanins, whereas the inheritance of cyanidin, 6-hydroxycyanidin, and delphinidin seems more complicated. Flower colour, hue, and intensity were measured by CIELab in fresh tepals and compared with their anthocyanin content and the estimated flavonoid concentrations. Colour intensity was positively correlated with anthocyanin concentration. Compared with flowers containing exclusively cyanidin 3-glycosides, the hues of flowers with delphinidin 3-glycosides were bluer and with 6-hydroxycyanidin 3-glycosides redder, respectively. Both malonation of anthocyanin and co-pigmentation with flavonoids caused a shift to bluish hues, irrespective of the anthocyanidins. By quantifying both chemical and colorimetric characteristics a model for the effect of anthocyanin on Alstroemeria flower colour was established. Breeding of new cultivars of Alstroemeria is discussed.     

葡萄果皮花色素苷提取工艺的研究

【目的】获得葡萄果皮中花色素苷提取最佳工艺。【方法】分析了提取剂、盐酸用量、提取温度、料液比、提取时间、提取次数对葡萄果皮中花色素苷提取率的影响,并在此基础上进行正交试验。【结果】最佳提取工艺为:用含体积分数0.1%盐酸的甲醇作为提取剂,40℃水浴中超声波辅助提取,提取时间50 min,料液比1∶7,提取2次。各因素对葡萄果皮中花色素苷提取率的影响程度依次为:提取次数>料液比>提取时间>提取温度。【结论】得到了葡萄果皮中花色素苷的最佳提取工艺,该工艺下花色素苷的提取率为73.10%。     

不同牡丹品种开花期间花瓣花青素和类黄酮组成的动态变化

【目的】牡丹（Paeonia suffruticosa）是中国传统名花之一,花色丰富,品种多样,通过测定不同花色品种在花朵开放期间花瓣花青素苷、类黄酮苷的种类和含量,并分析其动态变化规律,为牡丹花色的呈色机理及不同花色育种提供参考。【方法】选择5种不同花色的牡丹品种为试验材料,采集蕾期（S1）、露色期（S2）、盛开期（S3）和衰败期（S4）等4个不同时期的花瓣,利用高效液相色谱（HPLC）和质谱联用（LC-MS）技术对其花青素苷和类黄酮苷进行定性定量分析,比较不同花色品种之间的差异。【结果】检测到6种花青素苷和12种类黄酮苷。其中,紫色品种‘洛阳红’检测到的花青素苷种类最多,花瓣中共检测到4种花青素苷,而白色品种‘白雪塔’中未检测到花青素苷;在检测出的12种类黄酮苷中,芹菜素5-葡萄糖苷（7.18%—58.46%）、芹菜素己糖葡萄糖苷（1.44%—43.72%）和山奈酚3,7-葡萄糖苷（2.83%—43.44%）的相对含量明显高于其他物质。6种花青素苷在花朵开放期间不断积累,从蕾期（S1）至衰败期（S4）,花青素总含量不断增加,其中在盛开期（S3）总含量显著增加,在S4时期达到最高值。类黄酮物质总含量在花朵开放与衰老期间呈现先增加后降低的趋势,但不同品种的变化趋势差异明显。‘洛阳红’的类黄酮总含量在衰败期（S4）达到最大值（752.93±48.10）μg∙g^-1 FW,‘赵粉’在盛开期（S3）达到最大值（603.81±6.30）μg∙g^-1 FW,‘白雪塔’在露色期（S2）达到最大值（673.45±9.96）μg∙g^-1 FW,‘迎日红’和‘粉荷’均在蕾期（S1）达到最大值,其含量分别为（525.88±22.38）μg∙g^-1 FW和（740.56±16.08）μg∙g^-1 FW。【结论】不同颜色的牡丹品种中花青素苷和类黄酮苷差异较为显著,紫色品种花青素苷含量较高,白色品种几乎不含有花青素苷。花青素苷在花朵开放过程中不断积累,而类黄酮苷存在先积累后降解的变化趋势。