Differentiation of Non-articulated Laticifers in Poinsettia (Euphorbia pulcherrima Willd.)

Differentiation of non-articulated laticifers in poinsettia(Euphorbia pulcherrima Willd.) was studied ultra-structurally.Growing laticifers show: (1) a multinucleate apical region containingabundant ribosomes but few other differentiated organelles and(2) a sub-apical zone where the cytoplasm is dominated by vacuolesof diverse morphology with latex particles. These particlesappear first within narrow tubular vacuoles developed especiallyin the peripheral cytoplasm. During vacuolation of the laticifer,portions of cytoplasm, including some of the nuclei, becomeisolated by the enlarging and fusing vacuoles; eventually thesebecome lysed, except the latex particles which remain in thecentral vacuole. During differentiation of a laticifer branch,the cytoplasm contains the usual organelles, including a fewmicrobodies and coated vesicles. The plastids that lie withinthe peripheral cytoplasm differentiate into amyloplasts witha single elongated starch grain. Towards the end of differentiationthe cytoplasm becomes restricted to a thin parietal layer, withthe remaining organelles reduced or degenerate, surroundinga central vacuole filled with latex particles. Euphorbia pulcherrima Willd, poinsettia, ultrastructure, differentiation, laticifers     

Distribution and Organization of Non-articulated Laticifers in Mature Tissues of Poinsettia (Euphorbia pulcherrima Willd.)

The distribution and cytological organization of non-articulatedbranched laticifers in the mature root, stem, and leaf tissuesof poinsettia. Euphorbia pulcherrima Willd., were studied bythe use of optical and electron microscopy. The laticifers occurin all parts of the plant body, being well represented in certainparenchymatous tissues and the phloem. The mature region ofthe laticifer has a living protoplast showing a thin parietalcytoplasm, bounded by plasmalemma and a tonoplast, which enclosesa large continuous central vacuole containing the milky latexfluid. The protoplast is multinucleate and possesses large amyloplasts,each enclosing a single elongated starch grain. Sparseness andpoor differentiation of the other components of the protoplast,mostly mitochondria, ribosomes and endoplasmic reticulum, suggestlow metabolism in the mature region of the laticifer. The latexof the central vacuole is dominated by spherical particles,0.3–1 µm in diameter, each with a dense matrix andan eccentric core of lighter staining material. In some laticifersthe latex particles fuse into coagulated masses. Euphorbia pulcherrima Willd, poinsettia, laticifers, ultrastructure, cytology     

Axillary Bud Inhibition Induced by Young Leaves or Bract in Euphorbia pulcherrima Willd

In plants held under long days in the vegetative stage, youngexpanding leaves of poinsettia (Euphorbia pulcherrima Willd.‘Brilliant Diamond’) are the main source of axillarybud inhibition, while the apical bud, which includes the meristem,primordial leaves and small unfolded leaves, is a secondaryinhibition source. Removal of these expanding leaves resultedin rapid release and growth of axillary buds. Decapitation ofthe apical bud resulted in delayed axillary bud release. Inreproductive plants kept in short days, the pigmented bractsare the primary source of axillary bud inhibition and the cyathiaare the secondary source. Applications of NAA —substitutedfor both young leaves and bract inhibition — maintainedapical dominance. The concentration of endogenous auxin washighest in the apical bud. However, when calculated on wholeorgan basis the auxin level was greater in young developingvegetative leaves and in reproductive bracts than in the apicalbud. Euphorbia pulcherrima Willd, apical bud, apical dominance, auxin, correlative inhibition, cyathia, poinsettia, IAA, NAA     

叶子花花瓣状苞片和叶片的比较转录组学研究

叶子花(Bougainvillea spectabilis Willd.)的苞片色彩鲜艳,呈花瓣状,在景观园艺和环境美化有着广泛应用。为了进一步了解花瓣状苞片的演化机制,该研究采用RNA-seq技术分别对苞片和叶片进行测序,比较苞片和叶片在基因表达水平的差异。最终获得54.48 M对长度为150bp的双向clean reads,从头拼接出55 782条Unigenes,平均长度为1 003.79bp,N50为1 402bp。共有30 874条Unigenes能被注释到公共数据库,其中有12 631条Unigenes能被注释到基因本体。差异化表达分析确定苞片和叶片差异表达的基因共有456个。该研究分别对不同组织差异表达的基因进行GO富集分析和KEGG富集分析,结果表明,在苞片中高表达的差异化基因有黄酮类合成相关的基因,花色合成关键酶多巴双加氧酶(DODA)以及发现与花瓣发育相关的基因,在叶片中高表达的差异化基因主要是参与光合作用。     

一品红叶片的组织培养及其植株再生(简报)

一品红叶片外植体在MS IAA0．4mg／L 6-BA4．0mg／L的培养基上培养15d后产生疏松的浅绿色愈伤组织,30d后开始从愈伤组织表面分化产生幼芽,45d后平均每块愈伤组织产生15株幼芽。将幼芽转至含0．5mg／LIBA的MS培养基上形成根,再形成完整植株。     

High Uniformity of plants regenerated from cytogenetically variable embryogenic suspension cultures of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch)

Summary Shoot tip explants, callus and embryogenic cell suspensions of Euphorbia pulcherrima have been examined for quantitative variation in nuclear DNA content by means of cytophotometry. Increasing instability was found in calli and cell suspensions from Erlenmeyer flask and bioreactor culture. Nuclear DNA content ranged from 2C up to 32 C. Plants regenerated from embryogenic cell suspensions, however, were highly uniform with regard to phenotype and ploidy level indicating strongly impaired embryogenic potential of polyploid, aneuploid or other genetically altered cells.     

一品红试管苗移栽驯化期叶片的解剖结构变化

对一品红试管苗移栽驯化,同时研究了驯化过程中叶片结构的变化,结果表明,一品红在珍珠岩基质中成活率达98%,随着移栽时间的延长,表皮细胞增大,排列紧密;叶肉细胞间隙减小,栅栏组织细胞长度增加,主脉增厚,导管数目增加,保水,输水和抗逆能力增强。     

Local and systemic protection of poinsettia (Euphorbia pulcherrima Willd.) against Botrytis cinerea Pers. induced by benzothiadiazole

Benzothiadiazole (BTH) was found to be highly effective in increasing resistance of two poinsettia cultivars — ‘Coco White’ and ‘Malibu Red’, moderately susceptible to the fungus Botrytis cinerea. BTH applied at a concentration of 0.3 mM on the discs cut out from the leaves of these poinsettia cultivars reduced disease symptoms by more than 60 % in comparison to the control discs treated with water and exposed to infection. It was also observed that the applied inducer at a concentration of 0.03 and 0.3 mM had a favourable influence on the increase of poinsettia systemic resistance of SAR type (systemic acquired resistance). The effectiveness of BTH was much less when disease development was examined on detached leaves (a 20 % reduction of lesion area) in comparison with a pronounced inhibition of grey mould development on intact leaves of previously induced plants (a 80 % protection of intact plants). Benzothiadiazole in the concentration range from 0.03 to 1.4 mM added to in vitro agar medium was not found to have an inhibitory influence on Botrytis cinerea mycelium growth and sporulation.     

一品红体细胞胚胎发生与植株再生

一品红不同部位愈伤组织诱导能力存在差异,嫩茎>幼花序>嫩叶。愈伤组织的长势主要受生长素的影响,细胞分裂素对愈伤组织生长有促进作用;但在含6-BA和NAA的培养基中诱导出的愈伤组织,其胚性明显强于单独用NAA诱导出的愈伤组织。液体悬浮培养是一品红体细胞胚胎高频发生的中间步骤。不同浓度BA对一品红体细胞胚的萌发率影响不大,萌发培养基中KNO₃含量加倍可提高萌发率。     

一品红花色素抗氧化性能的研究

从一品红红色苞片中提取花色素,并用自由基测定试剂盒测试了一品红花色素的体外抗氧化性能,并用碘量法测定了其抑制猪油氧化的效果,用TBARS法测定其对血浆脂蛋白氧化的抑制能力。结果表明:一品红花色素具有较强的清除超氧阴离子(O2.-)和羟自由基(.OH)的能力,清除效果优于同浓度的VC;其对猪油氧化的抑制效果和同浓度的VC相近,而对人血浆脂质过氧化的抑制效果显著高于VC。     

一品红苞片花色素的分离及初步鉴定

用紫外-可见光分光光度计、高效液相色谱(HPLC)和质谱(MS)技术对一品红(Euphorbia pulcherrima)红色苞片中的花色素提取液进行了初步鉴定。一品红花色素的甲醇溶液分别在270、340 和520 nm 处有 3 个吸收峰; 在 440 nm 吸光度与可见光最大吸收波长 520 nm 吸光度的比值 为0.29; 花色素的甲醇溶液中加入AlCl3后发生红移, 再加入HCl后发生蓝移; 色素溶液在紫外光下无荧光; 色素样品经液相色谱分离后在 270 nm检测有 5 个比较明显的吸收峰; 质谱中得到 595、611、381、571 和 589 等对应的分子离子峰; 花色素酸解液高效液相色谱图谱和鼠李糖、葡萄糖的出峰时间一致。由这些结果可推断一品红花色素样品中主要含有 5 种组分: 矢车菊花色素芸香苷、飞燕草花色素芸香苷、飞燕草花色素苯甲酰基葡糖苷、矢车菊花色素苯甲酰基葡糖苷和一种未知成分。     

一品红苞片花色素的分离及初步鉴定

用紫外-可见光分光光度计、高效液相色谱（HPLC）和质谱（MS）技术对一品红（Euphorbia pulcherrima）红色苞片中的花色素提取液进行了初步鉴定.一品红花色素的甲醇溶液分别在270、340和520 nm处有3个吸收峰;在440 nm吸光度与可见光最大吸收波长520 nm吸光度的比值为0.29;花色素的甲醇溶液中加入AlCl3后发生红移,再加入HCl后发生蓝移;色素溶液在紫外光下无荧光;色素样品经液相色谱分离后在270 nm检测有5个比较明显的吸收峰;质谱中得到595、611、381、571和589等对应的分子离子峰;花色素酸解液高效液相色谱图谱和鼠李糖、葡萄糖的出峰时间一致.由这些结果可推断一品红花色素样品中主要含有5种组分：矢车菊花色素芸香苷、飞燕草花色素芸香苷、飞燕草花色素苯甲酰基葡糖苷、矢车菊花色素苯甲酰基葡糖苷和一种未知成分.     

Anti-inflammatory components of Euphorbia humifusa Willd.

Two new compounds, euphorbinoside (1) and dehydropicrorhiza acid methyl diester (2), along with 24 known compounds (3–26) were isolated from Euphorbia humifusa Willd. The effects of these compounds on soluble epoxide hydrolase (sEH) inhibitory activity were evaluated. Flavonoid compounds (10–21) exhibited high sEH inhibitory activity. Among them, compounds 12, 13, and 19 greatly inhibited sEH enzymatic activity, with IC₅₀ values as low as 18.05 ± 1.17, 18.64 ± 1.83, and 17.23 ± 0.84 μM, respectively. In addition, the effects of these compounds on lipopolysaccharide (LPS)-induced nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) production by RAW 264.7 cells were investigated. Compounds 3–6, 8, 18, 20–23, and 25–26 inhibited the production of both NO and TNF-α, with IC₅₀ values ranging from 11.1 ± 0.9 to 45.3 ± 1.6 μM and 14.4 ± 0.5 to 44.5 ± 1.2 μM, respectively.     

Sterols and triterpenols in latex and cultured tissues of Euphorbia pulcherrima

The sterol and triterpenol constituents of Euphorbia pulcherrima latex and cultured callus tissues were examined by GLC and mass spectrometry. Latex extracts from different varieties contained sitosterol, β-amyrin, germanicol, cycloartenol, β-amyrin acetate, and germanicol acetate. Capillary GC profiles of these varieties indicated that the triterpene content was essentially identical for examined latices. Cultured tissues derived from petioles and stem internodes synthesized only sitosterol in significant quantities, although trace amounts of several sterols that occur in latex were also detected in cultured tissues. This study supports the interpretation that the pattern of triterpene synthesis in the laticifer of the normal plant is a highly controlled and stable phenomenon among varieties of this species.     

Parallelism in hill activity and anthocyanidin content in Euphorbia pulcherrima

Pigment compositions and Hill activities of red-leafy bracts, red-green leaves and green leaves of E. pulcherrima were studied. Interestingly enough, the chloroplasts from anthocyanidin-containing leaves are intrinsically more active than those from green leaves.     

Arabinogalactan proteins in embryogenic and non-embryogenic callus cultures of Euphorbia pulcherrima

The arabinogalactan protein (AGP) fractions of embryogenic and non-embryogenic callus lines of Euphorbia pulcherrima Willd. ex. Klotzsch were analysed over a cultivation period of 9 weeks using the β -glucosyl Yariv reagent and an anti-AGP antibody (LM2). The amount of AGPs detected with the Yariv reagent increased in embryogenic cultures during the development of somatic embryos. The embryogenic and non-embryogenic callus contained different sets of AGPs characterized with the Yariv reagent and the LM2 monoclonal antibody. AGPs recognized by LM2 are localized primarily in the protodermal cells of globular somatic embryos. The development of somatic embryos of E. pulcherrima appears to be associated with the presence of particular AGPs.     

不同色彩珙桐苞片与叶片的生理特性研究

以生长在同一生境下的粉红珙桐和普通珙桐植株为试材,比较两种珙桐苞片/叶片的色素、基础代谢物含量和酶活性,探讨粉红珙桐苞片与叶片的呈色机理。结果显示：粉红珙桐叶片的类黄酮含量是普通珙桐的1.52倍,两种珙桐苞片中的类黄酮含量都较低,且无显著差异（P>0.05）;粉红珙桐苞片和叶片的花色苷含量极显著高于普通珙桐（P<0.01）,分别是普通珙桐的1.68倍和3.67倍;粉红叶片的光合色素略低于绿色叶片,但无显著差异（P>0.05）。粉红珙桐苞片和叶片的可溶性糖、脯氨酸含量显著高于普通珙桐（P<0.05）,可溶性蛋白含量则相反;苞片的可溶性糖含量极显著低于叶片（P<0.01）,而可溶性蛋白和脯氨酸含量更高（P<0.01）。粉红珙桐苞片和叶片的苯丙氨酸解氨酶（PAL）、查尔酮异构酶（CHI）活性极显著高于普通珙桐（P<0.01）,过氧化物酶（POD）和超氧化物歧化酶（SOD）活性无显著差异（P>0.05）;苞片中的酶活性大多都显著高于叶片（P<0.05）,尤其是CHI活性。类黄酮、花色苷含量与可溶性糖、脯氨酸含量、PAL、CHI活性呈显著正相关,而与可溶性蛋白含量显著负相关。研究表明,花色苷是珙桐苞片转粉红的直接因素,而叶片转粉红受类黄酮和花色苷的共同影响,可溶性糖、可溶性蛋白、脯氨酸、PAL、CHI影响花色苷的合成。