Histolocalization of chemotaxonomic markers in Brazilian Vernonieae (Asteraceae)

Vernonieae are well represented in South America by subtribe Lychnophorinae, with 104 Brazilian species, some of them rare and endangered. Lychnophorinae are well known for producing metabolites of high pharmaceutical and chemotaxonomic value. Despite the importance of secondary metabolites in Lychnophorinae, there is still little evidence regarding the secretory structures responsible for producing these compounds. Therefore, in this study we investigated 15 species representative of the main lineages of Lychnophorinae, with the following objectives: to identify where the chemotaxonomic markers of Lychnophorinae are secreted and stored and in which developmental stage of the organ these metabolites are found. Samples of stems and leaves were processed according to the usual techniques in plant anatomy. It was found that the main sites of secondary metabolite biosynthesis are glandular trichomes, epidermal cells and parenchyma tissues. Metabolites from glandular trichomes, especially sesquiterpene lactones (STL), are prevalent in the early developmental stages of organs. The metabolite compounds stored in parenchyma tissues are mainly terpenoids, flavonoids and other phenolic compounds; young and expanded leaves are equally rich in metabolites. Thus, the information obtained in this study is essential for conducting chemotaxonomic studies in this group, helping to promote selective collection and conservation of species.     

羽叶薰衣草表皮毛的发育解剖学研究

对羽叶薰衣草(LavandulapinnataL.)茎和叶上两种表皮毛(腺毛和非腺毛)发育的解剖学观察表明,两者的发生都源于茎或叶的原表皮细胞,但外部形态、发育过程及功能明显不同。腺毛有头状腺毛和盾状腺毛两种类型,均由1个基细胞、1个柄细胞和头部细胞构成。头状腺毛的头部只有1个或2个分泌细胞,盾状腺毛由8个分泌细胞构成头部。非腺毛由3-20个细胞组成,可分为三种类型:单列不分枝、二叉分枝和三叉及三叉以上多分枝的树状分枝。非腺毛的顶部细胞由基部到顶部逐渐变细,先端成尖形。腺毛发育由原表皮细胞经两次平周分裂形成,由于柄细胞和头部细胞所处的分化状态不同而发育成两类腺毛。非腺毛由非腺毛原始细胞经二次或多次平周分裂和不均等分裂,再发育成数个至二十多个子细胞。     

A role for intra- and intercellular translocation in natural product biosynthesis

The formation and storage of plant natural products such as phenylpropanoids, terpenoids and alkaloids are dynamic and complex processes that involve multiple subcellular compartments and cell types. Evidence is emerging to show that consecutive enzymes of phenylpropanoid and flavonoid biosynthesis are organized into macromolecular complexes that can be associated with endomembranes, that monoterpenoid biosynthetic enzymes are exclusively localized to highly specialized glandular trichome secretory cells and that complex monoterpenoid indole- and morphinan alkaloids require a combination of phloem parenchyma, laticifers and epidermal cells for their synthesis and storage. Highly ordered, protein-mediated processes that involve intra- and intercellular translocation need be considered when attempting to understand how a plant can regulate the formation and accumulation of complex but well-defined natural product profiles.     

臭椿茎中分泌道的发育及其组织化学研究

利用植物解剖学方法研究臭椿茎和叶柄中分泌道的结构、分布和发育过程.结果表明:臭椿茎和叶柄中的分泌道分布于髓的周缘,次生木质部中无分泌道.分泌道是由一层分泌细胞围绕分泌腔而构成,分泌细胞外有1～2层鞘细胞.分泌道以裂生方式形成,其发育过程可分为3个阶段:原始细胞阶段、形成阶段和成熟阶段.在原始细胞阶段,一群原始细胞具浓厚细胞质,细胞核清晰可见;形成阶段,原始细胞的中央细胞间细胞壁中层降解,细胞壁分离,形成腔隙,随着分泌细胞数量的增加,分泌腔体积扩大;成熟阶段的分泌道具有12～16个分泌细胞,1～2层鞘细胞,分泌腔直径为30～50μm.组织化学研究表明,分泌细胞及分泌道内含物中含大量的萜类、多糖和脂类物质.机械创伤能够诱导次生木质部中产生创伤分泌道.臭椿茎中的分泌道和创伤性分泌道在抵御生物和非生物胁迫中起重要作用.     

龙葵腺毛发育的细胞学研究

利用光学显微镜、扫描电镜和透射电镜技术,观察了龙葵“四叶一心”期时叶片及茎表皮的腺毛的种类、分布,探究了不同类型腺毛的起源、生长、成熟、分泌、衰老等发育过程的细胞学特征;通过组织化学染色和荧光显微技术,观察了龙葵腺毛成分、分布,为龙葵的进一步开发利用提供参考。结果表明：（1）龙葵腺毛分为单细胞头腺毛和多细胞头腺毛两类,前者主要分布于茎表面和叶上下表皮,后者主要分布于茎表面的单细胞头腺毛之间、叶脉及叶边缘;（2）龙葵腺毛发育起始于表皮细胞突起,单细胞头腺毛行顶端生长,具1-4个柄细胞,四种类型;多细胞头腺毛可再分为一层、两层与三层多细胞头腺毛,另具三种特殊类型;（3）龙葵成熟腺毛具分泌能力,通过皮下空间的物质积累导致腺毛头细胞表面形成突起、包块、破口,最终释放分泌物;而头细胞与柄细胞随即皱缩、衰老。（4）超微结构显示,腺毛头细胞中内质网与高尔基体极为丰富,合成代谢及分泌活动活跃,产生大量包裹嗜锇物质的囊泡,囊泡与细胞壁融合,进而将嗜锇物质转移至细胞壁并积累,随后储存在角质层下的皮下空间直至分泌释放;（5）组织化学染色结果表明,腺毛含有萜类、生物碱、脂类、蛋白质、酚类和多糖。头细胞中主要含有萜类、生物碱、脂类、蛋白质、酚类和中性多糖;柄细胞中主要含有萜类、生物碱、脂类。     

白鲜营养器官解剖结构及其与白鲜碱的积累关系

应用植物解剖学、组织化学及植物化学方法对白鲜营养器官根、茎、叶的结构及其生物碱的积累进行了研究。结果显示:(1)白鲜根的次生结构以及茎和叶的结构类似一般双子叶植物;白鲜多年生根主要由周皮、次生韧皮部、维管形成层以及次生木质部组成,根次生韧皮部中可见大量的淀粉、草酸钙簇晶、韧皮纤维以及油细胞;茎由表皮、皮层、维管组织和髓组成;叶由表皮、栅栏组织、海绵组织和叶脉组成;在茎和叶初生韧皮部的位置均分布有韧皮纤维,在叶表皮上分布有头状腺毛和非腺毛;在茎和叶紧贴表皮处分布有分泌囊。(2)组织化学分析结果显示:在白鲜多年生根中,生物碱类物质主要分布在周皮、次生韧皮部、维管形成层和木薄壁细胞中;在茎中,生物碱主要分布在表皮、皮层、韧皮部、木薄壁细胞及髓周围薄壁细胞中;在叶中,生物碱主要分布在表皮细胞、叶肉组织和维管组织的薄壁细胞;此外在分泌囊和头状腺毛中亦含有生物碱类物质。(3)植物化学结果显示,秦岭产白鲜根皮/白鲜皮、根木质部、茎和叶中白鲜碱含量分别为0.041%、0.012%、0.004%和0.002%,其中木质部中白鲜碱含量和其他部分地区白鲜皮中白鲜碱含量类似。研究表明,在秦岭产白鲜营养器官中,除根皮/白鲜皮外,在根木质部亦含有大量的白鲜碱,且在茎和叶中亦含有一定的白鲜碱,具有潜在的开发利用价值。     

唇形科植物腺毛及其分泌研究进展

唇形科植物的茎和叶通常着生腺毛,能分泌芳香油,腺毛的分布密度越大其分泌能力越强。对近年来该科植物腺毛及其分泌的研究进展作一综述,对腺毛的结构类型、发生发育和分泌物及其分泌过程作了介绍,指出了该研究领域中存在的问题。     

菱的腺毛发育及分泌活动的超微结构研究

菱的腺毛由单列圆筒状细胞组成,具有短暂的分泌功能。它们起源于叶片远轴面、叶柄的表皮细胞以及苗端茎轴、花柄的表皮细胞。处于分泌期的腺毛细胞其胞质浓厚,液泡化程度小,细胞具丰富的线粒体、高尔基体。腺毛丧失了分泌功能后即发育成为表皮毛。粘液物质由高尔基体分泌小泡携带至腺毛细胞侧壁,经胞吐与渗透结合的方式分泌至细胞外,粘液的化学成分主要为多糖。     

Glandular Trichomes in Satureja thymbra Leaves

The leaves of the aromatic plant Satureja thymbra have numerousglandular trichomes of two morphologically distinct types glandularhairs and glandular scales Investigations of the anatomy ofthese glandular trichomes with serial thick sections revealedthat the glandular hairs consist of three cells a foot, stalkand head cell Glandular scales also have a unicellular footand stalk Their heads, however, are composed of 12 cells Fourof these cells are small, occupying the central region of thehead, whereas the remainder are large and peripherally arrangedMorphometric analysis showed that, in leaf surface view, glandularscales are about 17-fold larger than glandular hairs In addition,glandular scales were found to occupy 5 7 % of the entire leafsurface area In each glandular scale the total amount of essentialoil, contained within both the subcuticular space and the interiorof the secretory cells, was calculated to be 2 51 x 10^–4mm³ The volume of the essential oil produced by all glandularscales on a single mature leaf was correspondingly determinedto be 0.059 mm³ Finally, the theoretical essential oil yieldof 100 g dry leaves of S thymbra was estimated to be 3 54 %(secretory activity of glandular scales only) Satureja thymbra, glandular trichomes, morphology, morphometry     

The effect of triacontanol on micropropagation and on secretory system of Thymus mastichina

Shoot multiplication of Thymus mastichina L. was achieved on media containing 0.1 mg l^–1 6-benzyladenine and/or 0.1 mg l^–1 indole-3-butyric acid, or in hormone-free medium (control). The growth of plantlets, the production and composition of the essential oil, the density and secretory stage of glandular hairs have been evaluated in the presence and absence of growth regulators and triacontanol. We observed a positive effect of triacontanol on the growth of micropropagated plantlets using different conditions. Media with different levels of BA, IBA and TRIA resulted in no differences in the composition of the essential oil produced by plantlets. The major components of the oil were 1,8-cineole and linalool. An increase in the oil yield was observed especially when triacontanol was added to hormone-free medium. There was no correlation between changes in the oil yield and glandular hairs density, but the yield was dependent on the secretory stage of the glands.     

紫苏腺毛的形态发生研究

紫苏叶上有两种腺毛：质状腺毛和头状腺毛。两者都具１个基细胞、１个柄细胞和头部。前者的头部可由１、２、４或８个分泌细胞组成,扩展成质状;后者的头部由１、２或４个分泌细胞组成,聚成圆球状。两种腺毛的原始细胞都来源于原表皮细胞,经两次平周分裂产生基细胞、柄细胞和顶细胞。在腺毛后期的形态发生中,柄细胞的分化状态决定腺毛的类型。若柄细胞保持扁平关且处于分生状态时,其顶细胞将发育成质状腺毛的头部;若柄细胞纵向     

紫苏腺毛的形态发生研究

紫苏叶上有两种腺毛:盾状腺毛和头状腺毛。两者都具1个基细胞、1个柄细胞和头部。前者的头部可由1、2、4或8个分泌细胞组成,扩展成盾状;后者的头部由1、2或4个分泌细胞组成,聚成圆球状。两种腺毛的原始细胞都来源于原表皮细胞,经两次平周分裂产生基细胞、柄细胞和顶细胞。在腺毛后期的形态发生中,柄细胞的分化状态决定腺毛的类型。若柄细胞保持扁平状且处于分生状态时,其顶细胞将发育成盾状腺毛的头部;若柄细胞纵向引长并迅速液泡化时,其顶细胞将发育成头状腺毛的头部。     

喜树幼枝的喜树碱积累及其组织内定位

对喜树幼枝发育过程中各组织结构变化的观察和喜树碱含量的分析,以及荧光显微技术对喜树碱的定位研究,结果表明,幼茎和幼叶表面的单细胞腺毛和幼茎及幼叶内部由1～2层细胞包围而成的分泌道是喜树碱的主要积累部位.     

Glandular trichomes of <Emphasis Type="Italic">Tussilago Farfara</Emphasis> (Senecioneae,Asteraceae)

Main conclusion

The glandular trichomes are developed on the aerial organs of Tussilago farfara ; they produce phenols and terpenoids. Smooth endoplasmic reticulum and leucoplasts are the main organelles of the trichome secretory cells. The aim of this study was to characterise the morphology, anatomy, histochemistry and ultrastructure of the trichomes in Tussilago farfara as well as to identify composition of the secretory products. Structure of trichomes located on the peduncles, bracts, phyllaries, and leaves were studied by light and electron microscopy. The capitate glandular trichomes consist of a multicellular head and a biseriate long stalk. Histochemical tests and fluorescence microscopy reveal phenols and terpenoids in the head cells. During secretory stage, the head cells contain smooth and rough endoplasmic reticulum, Golgi apparatus, diversiform leucoplasts with opaque contents in lamellae, chloroplasts, mitochondria, and microbodies. In the capitate glandular trichomes of T. farfara subcuticular cavity is absent, unlike glandular trichomes in other Asteraceae species. For the first time, content of metabolites in the different vegetative and reproductive organs as well as in the isolated capitate glandular trichomes was identified by GC–MS. Forty-five compounds, including organic acids, sugars, polyols, phenolics, and terpenoids were identified. It appeared that metabolite content in the methanol extracts from peduncles, bracts and phyllaries is biochemically analogous, and similar to the metabolites from leaves, in which photosynthesis happens. At the same time, the metabolites from trichome extracts essentially differ and refer to the above-mentioned secondary substances. The study has shown that the practical value of the aerial organs of coltsfoot is provided with flavonoids produced in the capitate glandular trichomes.

     

Parapodial glandular organs in Spiophanes (Polychaeta: Spionidae)—studies on their functional anatomy and ultrastructure

Parapodial glandular organs (PGOs) of Spiophanes (Polychaeta: Spionidae) were studied using light and electron microscopy. These organs are found in parapodia of the mid body region, starting on chaetiger 5 and terminating with the appearance of neuropodial hooks (chaetiger 14 or 15 in adult individuals). Large PGOs in anterior chaetigers display different species‐specific types of openings whereas small PGOs in posterior parapodia of the mid body region always open in a simple vertical slit. Each PGO is composed of three main complexes: (1) the glandular sac with several distinct epithelia of secretory cells and secretory cell complexes and the reservoir filled with fibrous material, (2) the gland‐associated chaetal complex (including the region of chaetoblasts and follicle cells, follicular canals, two chaetal collector canals, the combined conducting canal, the chaetal spreader including the opening of the glandular organ with associated type‐1 secretory cells, and the gland‐associated chaetae), and (3) a bilayered musculature surrounding the gland. A considerable number of different cell types are involved in the secretory activity, in the guidance of the gland‐associated chaetae, and in the final expulsion of the fibrous secretion at the opening slit. Among these different cell types the type‐5 secretory cells of the proximal glandular complex with their cup‐shaped microvilli emanating thick microfibrils into the lumen of the glandular sac are most conspicuous. Secretory cells with cup‐shaped microvilli being involved in the production of β‐chitin microfibrils have so far only been reported from some representatives of the deep‐sea inhabiting Siboglinidae (Polychaeta). We suggest that the gland‐associated chaetae emerging from inside the PGOs of Spiophanes are typical annelid chaetae formed by chaetoblasts and follicle cells. Functional morphology implies the crucial role of PGOs in tube construction. Furthermore, the PGOs are discussed in consideration of phylogenetic aspects. J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.     

Glandular trichomes and essential oil composition of endemic Sideritis italica (Mill.) Greuter et Burdet from central Italy

Sideritis italica (Mill.) Greuter et Burdet belongs to the Lamiaceae family and is endemic to Italy. The glandular trichomes (morphology, distribution, histochemistry, and ultrastructure) of the plant were studied for the first time, along with the chemical composition of the essential oils. Abundant non-glandular hairs and peltate (type A) and capitate (types B, C(1), and C(x)) glandular trichomes were observed both on the vegetative and reproductive organs. The histochemical procedures and the ultrastructural investigation enabled specific location of the main site of essential oil production mainly in type-A peltate hairs. Particular emphasis is given to the release mechanism of the secreted material in all of the types of glands, and the potential taxonomic value of the indumentum in the Lamiaceae family is briefly discussed. Essential oils were hydrodistilled from flowering aerial parts of S. italica, and 136 compounds (112 in flowerheads, 79 in vegetative parts) were identified. The quantitative prevalence of diterpenoids (43.4% in flowerheads and 22.3% in vegetative parts) was the most significant characteristic of the essential oil of S. italica that could be classified as a diterpene-rich essential oil according to the classification of Kirimer.     

紫苏腺毛的形态结构和发育的研究

紫苏（Perillafrutescens（L．）Britton）叶上腺毛的研究表明：叶上腺毛主要有两种类型,一是头状腺毛,二是后状腺毛。两类腺毛都是由1个基细胞、1个柄细胞和由分泌细胞组成的头部构成。头状腺毛的头部由1个、2个或4个分泌细胞构成,其头部呈圆球形或半圆球形。盾状腺毛的头部也由1个、2个、4个或8个分泌细胞构成,其分泌细胞横向扩展使头部呈盾状。分泌盛期,大量分泌物充满角质层下间隙。两类腺毛的原始细胞均起源于叶原基或幼叶的原表皮层细胞,它通过两次平周分裂形成1个基细胞、1个柄细胞和1个头细胞,头细胞不分裂或依次进行1—3次垂周分裂,分别形成单细胞、2细胞、4细胞或8细胞的头部。     

木香薷腺毛形态结构发生发育规律的研究

采用常规石蜡切片法及扫描电镜技术对木香薷(Elsholtzia stauntoni Benth)腺毛发生发育及其规律进行了研究。结果表明：木香薷表皮上主要有两种表皮毛：无分泌细胞的表皮毛与有分泌细胞的腺毛。前者包括单细胞乳头状毛、2~3细胞管状毛、分枝状毛及多细胞管状毛;后者包括头状腺毛与盾状腺毛。成熟头状腺毛头部由1、2或4个分泌细胞构成,头部呈圆球形或半圆球形;成熟盾状腺毛头部由8~12个分泌细胞构成,分泌细胞横向扩展形成盾状头部。木香薷腺毛主要在茎端幼叶处大量发生,从茎端第一对幼叶处开始产生;从幼叶期到成熟期均有腺毛发生,大部分腺毛在幼叶期发生发育,只有极少部分在叶的成熟期进行发生发育。     

Development of the glandular and non-glandular leaf hairs of Avicennia marina (Forsskål) Vierh.

The course of development of the glandular and non-glandular hairs of Avicennia marina was found to be the same up to the three-celled stage. The further cell divisions of the two types of developing hairs differed in their orientation. In the non-glandular hair the cells continued to divide transversely, whereas in the glandular hair the uppermost of the three cells divided longitudinally.
In the mature hairs of both types, the peripheral wall of the cell just above the basal cell was heavily cutinized. The existence of narrow canals in the cuticle of the secretory cells of the glandular hairs was confirmed. The homology of the glandular and non-glandular hairs is discussed and it is concluded that the two types are phylogenetically related.