高等植物花色苷的液泡摄取机制

综述了高等植物细胞中花色苷被液泡摄取的机制。花色苷通过细胞质中定位于粗糙内质网细胞质面的多酶复合体合成后被膜包裹形成囊泡。这些囊泡主要向液泡移动,在移动中相互融合形成更大囊泡,最终将花色苷带到液泡膜的表面。在大多数情况下,花色苷经过液泡膜上的各种载体被迅速运进液泡。另外两种较少的是:(1)囊泡直接与液泡融合;(2)液泡膜自主形成大的管状内陷,使囊泡在内陷处指向液泡内腔"发芽"。在上述种种可能的具体过程中,花色苷以非修饰或修饰两种形式被摄入液泡。花色苷跨液泡膜运送可能通过4种模型实现,即由ATP结合盒型的载体介导、由依赖pH梯度的载体介导、由24-kD液泡蛋白前体衍生的蛋白质介导和由多重药物和有毒化合物排出家族的载体介导。据推测,不同植物利用不同的摄取机制将花色苷积累在液泡中,而多重机制也可能被单个植物种同时使用。     

高等植物花色苷在液泡中的存在状态及其着色效应

综述了花色苷被摄入液泡的原因、花色苷在液泡中的存在状态及其对植物细胞的着色效应。花色苷在植物细胞质中合成后转运到液泡里是为了解除其对蛋白质和DNA等细胞功能分子的毒性。花色苷的液泡区隔化是花色苷在植物细胞中发挥正常功能的前提。在大多数植物中,花色苷在绝大多数情况下完全溶解在液泡里。但是,花色苷也能在液泡里形成颗粒,这些颗粒可以划分为花色苷体和花色苷液泡包涵体两类。花色苷体由膜包裹,其形成是液泡中小的有色囊泡逐渐合并的结果,发育完全的花色苷体为典型的球状、具比液泡更深的红色;液泡里的花色苷体具高密度,呈现为含高浓度花色苷的不溶性小球;花色苷体的存在可导致液泡的强烈色彩。花色苷液泡包涵体可能具备蛋白质基质,既无膜包裹又无内部结构,其形成是转运进液泡的花色苷与蛋白质基质结合的结果;液泡里的花色苷液泡包涵体形状不规则,象果冻;在花色苷液泡包涵体中,花色苷可能通过氢键连接于蛋白质基质的一个有限空间位点;花色苷液泡包涵体被认为是液泡中花色苷的"陷阱",优先摄取花色素3,5-二糖苷或酰化的花色苷;花色苷液泡包涵体的存在可增加液泡色彩的强度并导致"蓝化"。     

高等植物的性别决定及进化

高等植物的性别决定及进化李雅轩（北京师范学院分院生物系１０００３１）在高等植物中,绝大多数植物属于雌雄同体种类,而仅有一少部分植物属于雌雄导株类型。例如：喷瓜（Ｅｃｂａｌｌｉｕｍｅｌａｔｅｒｉｕｍ）、大麻属（Ｃａｎｎａｂｉｓ）、草属（Ｈｕｍｕｌｕｓ）...     

高等植物花器官的特异性基因

生殖过程是高等植物生活史中最重要的阶段,它不能仅被看作是一个精子与卵细胞结合的简单过程。实际上它包括雌雄配子体的发育、雄配子体与雌配子体的识别及相互作用、精子与卵细胞的识别及相互作用等一系列复杂的生理生化变化。对于被子植物来说,还存在着双受精这样一个更为复杂的过程。因此,作为这一生理过程的主要执行器官,花器官的生长发育就格外受到生物学家们的重视。早期对于花器官的研究主要集中     

高等植物的性别与性别决定机制

生物在进化过程中出现了性别,有性繁殖是真核生物繁殖的主要形式,并导致了大多数真核生物两性异型的进化。本简要介绍了植物的性多态现象及雌雄异株植物的性染色体,主要介绍了雌雄异株植物的性别决定系统的三种基本类型,并与动物的性别决定系统作了比较。     

植物花色苷生物合成酶类的亚细胞组织研究进展

花色苷类化合物是类黄酮合成途径的有色末端产物,其合成需要多种酶类催化完成.花色苷生物合成的相关酶在细胞质中被组织成与膜联系的多酶复合体,该复合体对于花色苷生物合成途径的整个效率、专一性和调节具有重要意义.本文对植物花色苷生物合成相关酶的亚细胞定位、所形成的复合体的模型及其存在问题进行了综述.花色苷生物合成多酶复合体的建立将有助于演绎出一个关于细胞代谢的新“三维观”,可为花色苷生产的代谢工程的理性调控创造更有效的手段.     

山葡萄果实发育过程中花色苷和非花色苷酚成分及其含量的变化

以‘双红’山葡萄果实为试材,采用HPLC—MS／MS技术,分析山葡萄果实发育过程中果皮中花色苷和非花色苷酚成分及其含量的变化。结果表明,转色期前果皮内没有花色苷积累,随着果实的成熟,花色苷含量逐渐增加,成熟期的含量最高;非花色苷酚自花后2周至成熟期间的含量变化呈下降趋势。在山葡萄果实发育过程中检测出花色苷10种,其中双糖苷5种、单糖苷5种;非花色苷酚类物质检测到14种,其中苯甲酸类2种、肉桂酸类3种、黄烷-3-醇类2种、黄酮醇类5种、白藜芦醇类2种。     

pH对马铃薯‘转心乌’块茎花色苷颜色变化及降解速率的影响

用分光光度法在体外研究了不同pH条件下马铃薯'转心乌'块茎花色苷颜色呈现和降解速率的变化,以探讨马铃薯'转心乌,块茎颜色呈现的机理.结果显示:在pH 2.0时,该花色苷呈现最强烈的红色.随着pH从0增加到13.0,该花色苷在可见光区的最大吸收波长(λvis max)依次出现红移、蓝移,然后消失,在可见光区的最大吸收波长处的吸光值(Aλ,vis max)呈现为一条单峰曲线,峰值在pH 2.0处.当原始pH值被恢复到2.0后,如果原始pH小于或等于5.0,花色苷的红色均被恢复得更浓烈,λvis max不同程度地趋向537 nm,Aλ,vis max增加;如果原始pH大于或等于6.0,花色苷的红色根本不能被恢复,λvis max几乎不变,Aλ,vis max仍然维持低水平.在15℃、黑暗中,该花色苷在pH 0～5.0条件下均随时间推移而降解,在pH 2.0时的降解速度最慢;当pH小于或等于3.0时,该花色苷总体上降解缓慢,而且降解过程基本符合一级反应动力学.研究表明,'转心乌'块茎花色苷在可见光区的吸收光谱和在15℃、黑暗中的降解速度均具pH依赖性.     

花色苷的酶降解

综述了降解花色苷的酶类及其降解机理的研究进展.降解花色苷的酶有花色苷酶、多酚氧化酶、过氧化物酶和果胶酶.花色苷酶和果胶酶均能水解花色苷糖苷键产生花色素和糖,花色素很不稳定,因吡喃烊环极易开环可自发转换成无色衍生物.花色苷不能直接作为PPO或POD的底物;PPO和POD氧化、降解花色苷须依赖具邻二酚结构的其他酚类的存在,...     

水稻种子花色苷形成及其对稻谷储藏特性的影响

花色苷是有色稻种皮和颖壳里呈现颜色的主要物质,属于类黄酮类物质,具有抗氧化性。本研究围绕水稻种子形成过程中花色苷含量的变化以及其对稻谷储藏特性变化的影响,探讨花色苷在稻谷储藏中延长种子寿命的作用。结果显示:选取的3个品种中,水稻种子的花色苷形成主要在发育初期,随着颖果体积的增大,颖果花色苷的含量会逐渐降低,而颖壳的花色苷含量变化不显著,将种子进行人工老化后,仍只有颖果的花色苷含量出现下降的趋势,表明种子在老化过程中颖壳的花色苷不参与抗老化的各项代谢反应。老化种子SOD活性分析显示,花色苷含量低的中籼9311可能是通过SOD酶活性增加,削减高温高湿胁迫对种子衰老的影响;由稻谷感染霉菌情况显示在3个水稻品种中,花色苷含量高的品种的抗霉菌能力要稍优于花色苷含量低的品种。但综合来看,花色苷含量高低并不是决定种子寿命的主要因素。     

A rapid,sensitive and accurate determination of indolyl-3-acetic acid

A method is described for the routine determination of absolute amounts of free indolyl-3-acetic acid (IAA) in plant material. The time required for a determination is in the order of 2 hr. Several samples can be handled at the same time. Depending on the contents of IAA, the amount of fresh plant material varies from 0·05 to 5 g. Losses are corrected for by applying ¹⁴C-labeled IAA.     

Anthocyanins and flavonols from the blue flowers of six Meconopsis species in Bhutan

Blue flowers of six Bhutani Meconopsis species, M. bhutanica, M. bella, M. horridula, M. simplicifolia, M. primulina and M. polygonoides, were surveyed for anthocyanins and other flavonoids. Four anthocyanins were isolated and identified as cyanidin 3-O-sambubioside-7-O-glucoside (1), cyanidin 3-O-[xylosyl-(1 → 2)-(6″-malonylglucoside)]-7-O-glucoside (2), cyanidin 3-O-sambubioside (4) and cyanidin 3-O-[xylosyl-(1 → 2)-(6″-malonylglucoside)] (5). On the other hand, 12 flavonols were isolated from their Meconopsis species with various combination and characterized as kaempferol 3-O-glycosides (8–12), kaempferol 3,7-O-glycosides (13–16), quercetin 3-O-glycosides (17 and 18) and isorhamnetin 3-O-glycoside (19). Of six Meconopsis species which were surveyed in this experiment, anthocyanin and flavonol composition of five species except for M. horridula was clarified for the first time. Their Meconopsis species showed the different flavonoid profiles, respectively, and flavonoid diversity within the glycosylation level of Meconopsis flowers were indicated.     

Anthocyanins and flavonols from the flowers of Amherstia nobilis endemic to Myanmar

Three anthocyanins (1–3) and eight flavonols (4–11) were isolated from the flowers of Amherstia nobilis endemic to Myanmar. Anthocyanins were identified as cyanidin 3-O-glucoside (1), 3-O-xyloside (2), and peonidin 3-O-glucoside (3). On the other hand, flavonols were identified as isorhamnetin 3-O-glucoside (4), 7-O-glucoside (5), 3,7-di-O-glucoside (6) and 3-O-rutinoside (7), quercetin 3-O-rutinoside (8) and 3-O-glucoside (9), and kaempferol 3-O-rutinoside (10) and 3-O-glucoside (11). Although an anthocyanin, pelargonidin 3-O-pentoside, has been reported from the flowers of A. nobilis, it was not found in this survey. The presence of flavonols in A. nobilis was reported in this survey for the first time. Flavonoid composition of Amherstia was chemotaxonomically compared with those of phylogenetically related genera Cynometra and Brownea.     

重度盐碱地改良措施对土壤特性和不同植物光合、生长的影响

研究了重度盐碱地改良对土壤特征及不同植物光合生长的影响,结果发现：实施不同改良措施后,土壤特性方面发生了显著变化,土壤总孔隙度比对照（盐碱裸地）提高5%~20%;田间持水量比对照提高3%~13%;土壤容重由对照的1.2~1.4 g·cm^-3降到0.7～1.0 g·cm^-3;土壤紧实度由对照的2 000~2 500 kPa降低到500~1 000 kPa;土壤毛细管上升高度和土壤透水速率也高于对照;土壤电导率平均降低了1 288 μs·cm^-1;土壤pH值平均降低1.5左右;浅槽改良和深槽改良后碱解氮分别提高了50%和100%;浅槽改良和深槽改良后土壤CO₂浓度达到2 500～3 500和3 000～3 500 μL·L^-1;深槽改良使得土壤深层氧气浓度下降到17%左右。改良后种植的植物光合能力方面也有不同提高,其中甘草、甜玉米和偃柏等经深槽改良处理后比对照提高2.5~12 μmol·m^-2·s^-1。不同植物经过处理后在生物量方面明显提高,其中甜玉米、白菜、萝卜和偃柏等深槽改良处理明显高于其客土覆盖处理,我们的研究表明大规模盐碱地改良后种植品种选择应该因地制宜,综合考虑其土壤特性和植物适应性。     

Morphogenesis and Patterning at the Organ Boundaries in the Higher Plant Shoot Apex

Formation of lateral organ primordia from the shoot apical meristem creates boundaries that separate the primordium from surrounding tissue. Morphological and gene expression studies indicate the presence of a distinct set of cells that define the boundaries in the plant shoot apex. Cells at the boundary usually display reduced growth activity that results in separation of adjacent organs or tissues and this morphological boundary coincides with the border of different cell identities. Such morphogenetic and patterning events and their spatial coordination are controlled by a number of boundary-specific regulatory genes. The boundary may also act as a reference point for the generation of new meristems such as axillary meristems. Many of the genes involved in meristem initiation are expressed in the boundary. This review summarizes the cellular characters of the shoot organ boundary and the roles of regulatory genes that control different aspects of this unique region in plant development.     

衍生化UPLC-MS法测定酸性植物激素

为有效利用超高效液相-高分辨率飞行时间质谱(UPLC-TOF-MS)对酸性植物激素进行定性定量分析,选取几种有机酸衍生化试剂:2-溴苯乙酮(BP)、2-二甲氨基乙胺(DMED)、1-(3-二甲基氨基丙基)-3-乙基碳二亚胺(EDC)和溴代丙酮基三甲基溴化铵(BTA),分别与脱落酸(ABA)、赤霉素(GA3)、吲哚乙酸(IAA)、茉莉酸(JA)和水杨酸(SA)进行衍生化反应。通过比较上述各植物激素的质谱响应值,判断衍生化试剂的效果。将植物激素标准品进行浓度梯度稀释,并与衍生化试剂反应,测定它们的定量限。用衍生效果最佳的试剂与植物粗提液反应,检验其应用效果。结果显示,几种衍生化试剂均可大幅度提高酸性植物激素的质谱响应值,其中DMED衍生后植物激素的质谱灵敏度提高幅度最大,且反应稳定、重复性好。DMED衍生后, ABA、GA3、IAA、JA和SA的定量限分别为0.05、0.2、0.1、0.1和0.5 ng·mL^–1,与未衍生化相比,分别降低100、25、50、50和10倍,即DMED衍生化使几种植物激素的质谱灵敏度提高10–100倍,显著高于目前报道的灵敏度。将该方法应...     

Distribution of γ-Tubulin in Higher Plant Cells: Cytosolic γ-Tubulin is Part of High Molecular Weight Complexes

Abstract: γ-Tubulin is a protein found in all eukaryotic cells, where it plays a key role in the nucleation of microtubules. In higher plant cells, γ-tubulin is localized at the nuclear surface, a known microtubule-organizing centre, and is codistributed with all microtubule arrays. Functions of plant γ-tubulin remain to be determined. This study describes some properties of higher plant γ-tubulin. The overall level of γ-tubulin was constant during the cell cycle in synchronized tobacco BY-2 cells. Biochemical analysis of the subcellular distribution of γ-tubulin in maize cells revealed that, in contrast with animal γ-tubulin, plant γ-tubulin is mainly associated with endomembranes. We showed for the first time that the pool of soluble cytosolic γ-tubulin contained two main γ-tubulin complexes. γ-tubulin, Hsp70 and TCP1-related proteins might interact in a small complex of 750 kDa. A second γ-tubulin complex, larger than 1500 kDa was purified. The protein profile of this large complex was very similar to animal γ-tubulin complexes. The putative functions of these two complexes in plant microtubule nucleation are discussed.     

A Screening Analysis of the High‐Pressure Extraction of Anthocyanins from Red Grape Pomace with Carbon Dioxide and Cosolvent

In the work described here, a set of screening factorial design experiments was carried out in order to study the extraction process of anthocyanins from red grape pomace with carbon dioxide, along with either methanol or water as cosolvent, at high pressure. The variables studied were pressure, temperature, solvent flow‐rate, cosolvent percentage, cosolvent type (methanol or water) and extraction time. The quantification of the total amount of anthocyanins was performed by a colorimetric method. The results of the ANOVA study show a strong influence of the type and percentage of cosolvent. The best results were obtained with 20 mol‐% of methanol, 100 bar, 60 °C and a flow‐rate of 22 mmol/min after two hours of extraction.     

血液杆菌Haem atobacter sp.细胞脂肪酸测定的影响因素

应用美国MIDI公司Sherlock MIS系统检测一株归属于血液杆菌属的新菌种Haematobacter sp.HNMC11807的细胞脂肪酸组成,探讨不同培养方法和条件对其细胞脂肪酸组成的影响。采用不同培养条件培养微生物细胞,即不同的培养基组成、固液类型和培养时间;分析比较细胞脂肪酸检测结果存在的差异。同时对比分析仪器专用的两种检测体系,即常规标准和快速标准体系,对样品脂肪酸测定结果的影响。结果发现,细胞脂肪酸组成与其培养条件密切相关,且差异显著。因此,在应用该系统做微生物分类鉴定时,必需严格遵守特定的、统一的培养条件平行进行。