Flavonoids and xanthones from the leaves of Amorphophallus titanum (Araceae)

The flavonoids and xanthones in the leaves of Amorphophallus titanum, which has the largest inflorescence among all Araceous species, were surveyed. Eight C-glycosylflavones, five flavonols, one flavone O-glycoside and two xanthones were isolated and characterized as vitexin, isovitexin, orientin, isoorientin, schaftoside, isoschaftoside, vicenin-2 and lucenin-2 (C-glycosylflavones), kaempferol 3-O-robinobioside, 3-O-rutinoside and 3-O-rhamnosylarabinoside, and quercetin 3-O-robinobioside and 3-O-rutinoside (flavonols), luteolin 7-O-glucoside (flavone), and mangiferin and isomangiferin (xanthones). Although the inflorescence of this species has been surveyed for flavonoids, those of the leaves were reported for the first time.     

Calcium oxalate crystal types and trends in their distribution patterns in leaves ofPrunus (Rosaceae: Prunoideae)

Calcium oxalate crystal types and distribution within leaves ofPrunus sensu lato (Rosaceae; Prunoideae) were surveyed from mostly herbarium specimens (196 specimens of 131 species of all five subgenera usually recognized). Rehydrated samples were bleached, mounted unstained, and viewed microscopically between crossed polarizers. Six patterns were recognized based on crystal type and relative distribution around veins and in mesophyll. Druses predominate in four subgenera, but prismatics are most common in subgenus Padus. Prunophora and Amygdalus, considered to be the most advanced subgenera, have virtually only druses, which are almost always associated with veins. Cerasus and Laurocerasus, intermediate subgenera, have the greatest diversity of patterns, but few species with prismatics. A trend is evident from mostly mesophyll prismatics in Padus to fewer prismatics and more druses of mixed distribution in Laurocerasus and Cerasus, to mostly druses restricted to veins in Amygdalus and Prunophora.     

Crystal macropattern development in Prunus serotina (Rosaceae, Prunoideae) leaves

BACKGROUND AND AIMS: Prunus, subgenus Padus, exhibits two completely different calcium oxalate crystal macropatterns in mature leaves. Foliar macropattern development has been described previously in P. virginiana, representing one version. Prunus serotina, in the group exhibiting the second macropattern, is described here. The goal was to describe developmental details for comparison with P. virginiana, and to extend the sparse current knowledge of crystal macropatterns. METHODS: Leaves at various developmental stages were removed from local trees and from herbarium specimens. Early leaf stages and freehand leaf and stem sections were mounted directly in aqueous glycerine; larger leaves were processed whole or in representative pieces in household bleach, dehydrated in alcohol/xylol, and mounted in Permount. Crystals were detected microscopically between crossed polarizers. KEY RESULTS: Bud scales have a dense druse population. Druses appear first at the stipule tip and proliferate basipetally but soon stop forming; growing stipules therefore have a declining density of druses. Druses appear at the tip of leaves <1 mm long, then proliferate basipetally in the midrib. Lamina druses appear in the distal marginal teeth of leaves 3 cm long; from here they proliferate basipetally and towards midrib along major veins. In about two-thirds-grown leaves (6-9 cm length) druses are all adaxial to veins of most orders; a shift occurs then to formation of prisms, which appear first abaxial to, then all around, veins. Mature leaves have virtually all prisms encrusting all major veins, more sparsely along smaller minor veins. Late season leaves form epitactic crystals on existing prismatics. CONCLUSIONS: The developing and mature macropattern of P. serotina is almost the reverse of the pattern described previously in P. virginiana, and shows that two closely related species can develop radically different modes of crystallization. The few detailed macropattern studies to date reveal striking variations that indicate a new level of organization that must be integrated with the anatomical, physiological and molecular approaches that have been dominant so far.     

Unusual metaxylem tracheids in petioles of Amorphophallus (Araceae) giant leaves

BACKGROUND AND AIMS: Petioles of huge solitary leaves of mature plants of Amorphophallus resemble tree trunks supporting an umbrella-like crown. Since they may be 4 m tall, adaptations to water transport in the petioles are as important as adaptations to mechanical support of lamina. The petiole is a cylindrical shell composed of compact unlignified tissue with a honeycomb aerenchymatous core. In both parts numerous vascular bundles occur, which are unique because of the scarcity of lignified elements. In the xylemic part of each bundle there is a characteristic canal with unlignified walls. The xylem pecularities are described and interpreted. MATERIAL: Vascular bundles in mature petioles of Amorphophallus titanum and A. gigas plants were studied using light and scanning electron microscopy. KEY RESULTS: The xylemic canal represents a file of huge metaxylem tracheids (diameter 55-200 microm, length >30 mm) with unlignified lateral walls surrounded by turgid parenchyma cells. Only their end walls, orientated steeply, have lignified secondary thickenings. The file is accompanied by a strand of narrow tracheids with lignified bar-type secondary walls, which come into direct contact with the wide tracheid in many places along its length. CONCLUSIONS: The metaxylem tracheids in A. petioles are probably the longest and widest tracheids known. Only their end walls have lignified secondary thickenings. Tracheids are long due to enormous intercalary elongation and wide due to a transverse growth mechanism similar to that underlying formation of aerenchyma cavities. The lack of lignin in lateral walls shifts the function of 'pipe walls' to the turgid parenchyma paving the tracheid. The analogy to carinal canals of Equisetum, as well as other protoxylem lacunas is discussed. The stiff partitions between the long and wide tracheids are interpreted as structures similar to the end walls in vessels.     

Morphologies and elemental compositions of calcium crystals in phyllodes and branchlets of Acacia robeorum (Leguminosae: Mimosoideae)

Background and Aims

Formation of calcium oxalate crystals is common in the plant kingdom, but biogenic formation of calcium sulfate crystals in plants is rare. We investigated the morphologies and elemental compositions of crystals found in phyllodes and branchlets of Acacia robeorum, a desert shrub of north-western Australia.

Methods

Morphologies of crystals in phyllodes and branchlets of A. robeorum were studied using scanning electron microscopy (SEM), and elemental compositions of the crystals were identified by energy-dispersive X-ray spectroscopy. Distributional patterns of the crystals were studied using optical microscopy together with SEM.

Key Results

According to the elemental compositions, the crystals were classified into three groups: (1) calcium oxalate; (2) calcium sulfate, which is a possible mixture of calcium sulfate and calcium oxalate with calcium sulfate being the major component; and (3) calcium sulfate · magnesium oxalate, presumably mixtures of calcium sulfate, calcium oxalate, magnesium oxalate and silica. The crystals were of various morphologies, including prisms, raphides, styloids, druses, crystal sand, spheres and clusters. Both calcium oxalate and calcium sulfate crystals were observed in almost all tissues, including mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex; calcium sulfate · magnesium oxalate crystals were only found in mesophyll and parenchyma cells in phyllodes.

Conclusions

The formation of most crystals was biologically induced, as confirmed by studying the crystals formed in the phyllodes from seedlings grown in a glasshouse. The crystals may have functions in removing excess calcium, magnesium and sulfur, protecting the plants against herbivory, and detoxifying aluminium and heavy metals.     

Isolation and characterization of polymorphic microsatellite markers in Amorphophallus paeoniifolius (Dennst.) Nicolson,Araceae

Amorphophallus paeoniifolius is an herbaceous perennial tuber crop distributed widely in many Asian countries. We isolated 19 polymorphic loci from A. paeoniifolius using a dual‐suppression‐PCR technique. These loci provide microsatellite markers with high polymorphism ranging from three to 24 alleles per locus. The observed and expected heterozygosities ranged from 0.521 to 0.854 and from 0.766 to 0.930, respectively. This high allelic diversity indicates that our markers are suitable for a population study in A. paeoniifolius.     

A torch in the rain forest: thermogenesis of the Titan arum (Amorphophallus titanum)

An outstanding flagship species in the plant kingdom is the Titan arum ( Amorphophallus titanum ), which produces a fountain-like bloom up to 3 m high. The unique appearance of three simultaneous inflorescences in May 2006 was a chance to analyse the flowering behaviour and thermogenesis of this giant. For the first time, the heating of the central column (spadix) could be documented using a high-performance thermographic camera. Time series analyses of the infrared image sequences revealed that the 3-m high spadix surface heats up in pulses emanating from the base of the inflorescence. The surface temperature reaches over 36 °C, compared to the ambient temperature of 27 °C. Waves of the carrion-like odour are synchronised with these heat pulses. The combination of heat pulses, the fountain-like shape plus the enormous size lead to a unique type of 'convection flower'. On the basis of our observations, we assume that Amorphophallus titanum is able to overcome thermodynamic decoupling by a self-produced convective process.     

弥勒魔芋珠芽发育过程的形态学和解剖学研究

珠芽是弥勒魔芋的一种重要营养繁殖器官。以弥勒魔芋为材料,通过形态学观察以及解剖学研究,揭示了弥勒魔芋珠芽形成过程中的一系列特征。结果显示:弥勒魔芋珠芽生长于植株叶柄分叉以及裂叶分叉处,由主干茎或主干叶柄表皮下的薄壁细胞重新获得分裂能力后分化而来。珠芽的发育过程可分为珠芽原基启动形成期,珠芽膨大期和珠芽成熟期。珠芽的生长终止于植株衰老倒伏。研究表明,弥勒魔芋的珠芽生长位点明显区别于其他常见植物,珠芽繁殖是魔芋适应生态环境的一种重要机制。     

金沙江干热河谷特有植物白魔芋的传粉生物学研究

以金沙江干热河谷特有植物白魔芋（Amorphophallus albus P.Y.Liu et J.F.Chen）为对象,分别在两个就地栽培实验地（四川金阳、云南永善）和一个异地栽培实验地（富源）进行传粉生物学研究（包括交配系统及气味和传粉昆虫对其繁殖策略的影响）。结果显示,白魔芋是雌雄异熟且雌蕊先熟,雌花期时,附属器散发浓烈的恶臭气味。经气相色谱-质谱联用仪（GC-MS）分析,花气味成分主要为二甲基二硫和二甲基三硫。野外观察到的传粉昆虫属于隐翅虫科（Staphylinidae）,包括前角隐翅虫亚科（Aleocharinae）的Atheta sp.和颈隐翅虫亚科（Oxytelinae）的Anotylus sp.。经气相色谱-触角电位联用技术（GC-EAD）分析表明,隐翅虫触角对白魔芋花气味中的二甲基二硫和二甲基三硫有明显的反应。授粉结果显示,金阳、永善和富源3个实验地人工自花授粉和套袋的结实率都为0,无传粉昆虫的富源实验地自然结实率也为0。综合研究结果表明白魔芋属于自交不亲和的交配系统,通过花序结构和气味吸引隐翅虫为其传粉,并提供食物和交配场所作为回报。该研究为白魔芋的繁殖育种提供了基础资料,为植物与昆虫之间的协同进化提供了进一步的理论支持,同时为白魔芋的有效保护和利用提供了理论依据和技术指导。     

Infrared thermography and odour composition of the Amorphophallus gigas (Araceae) inflorescence: the cooling effect of the odorous liquid

During the second blooming of a cultivated Amorphophallus gigas Teijsm and Binnend in the Botanical Gardens of the University of Tokyo, the surface temperature of the inflorescence was measured using an infrared camera. Contrary to studies of other species in the genus Amorphophallus, the surface of the inflorescence showed only very faint thermogenesis and had a lower temperature than that of the background. This cooling effect appeared to be due to a loss of heat through evaporation, which was caused by the secretion of a very large amount of odorous liquid. Chemical analysis revealed that the major components of this liquid were acetic acid, propionic acid, butyric acid and valeric acids. The composition of the odorous liquid was slightly different between the spathe surface and the sterile appendix. The major component(s) of the odorous material from the spathe was butyric acid, and from the sterile appendix was valeric acids. These components would play dual roles of adding the characteristic smell to the inflorescence and cooling the inflorescence.     

Cytology and systematics in JapaneseArisaema (Araceae)

Chromosome numbers are determined from 37 populations attributed to 22 taxa of JapaneseArisaema. Of them, chromosome numbers ofA. limbatum var.conspicuum (2n=26),A. minus (2n=26),A. nambae (2n=28) andA. seppikoense (2n=26) are determined for the first time. New chromosome numbers, 2n=26, are reported forA. aequinoctiale, A. limbatum, A. stenophyllum, A. undulatifolium andA. yoshinagae. Three modes of basic chromosome numbers,x=14,x=13 andx=12, occur in JapaneseArisaema. Precise karyotypic comparisons of 20 taxa reveal that taxa withx=14 andx=13 share 26 major chromosome arms and have an obvious chromosomal relationship. One of two submeta-centric chromosomes inx=13 corresponds to two telo-centric chromosomes inx=14. InA. ternatipartitum with 2n=6x=72, ten out of 12 basic chromosomes are the most similar in size and arm ratio with larger ten chromosomes ofA. ringens among JapaneseArisaema examined. A basic chromosome number ofx=14 is the commonest in the genusArisaema and the remaining basic chromosome numbers,x=13 andx=12, seem to be derived through dysploidal reduction by translocating large segments of major arm of telo-centric chromosome onto other minor arm of telo-centric followed by loss of the remainings including a centromere, and by loss of two telo-centrics fromx=14, respectively. Some systematic problems of JapaneseArisaema are discussed based on new cytological data.Arisaema hatizyoense, A. minus andA. nambae are accepted as independent species.     

Quantitative determination of calcium oxalate and oxalate in developing seeds of soybean (Leguminosae)

Developing soybean seeds accumulate very large amounts of both soluble oxalate and insoluble crystalline calcium (Ca) oxalate. Use of two methods of detection for the determination of total, soluble, and insoluble oxalate revealed that at +16 d postfertilization, the seeds were 24% dry mass of oxalate, and three-fourths of this oxalate (18%) was bound Ca oxalate. During later seed development, the dry mass of oxalate decreased. Crystals were isolated from the seeds, and X-ray diffraction and polarizing microscopy identified them as Ca oxalate monohydrate. These crystals were a mixture of kinked and straight prismatics. Even though certain plant tissues are known to contain significant amounts of oxalate and Ca oxalate during certain periods of growth, the accumulation of oxalate during soybean seed development was surprising and raises interesting questions regarding its function.     

Cytoplasmic streaming of calcium oxalate crystals in Callipsygma wilsonis (Bryopsidales, Chlorophyta)

Light microscopic study of the giant‐celled, marine green alga Callipsygma wilsonis J. Agardh (Udoteaceae, Bryopsidales) revealed numerous birefringent crystalline inclusions in the terminal segments of the assimilatory axes. The inclusions were thin plates with a triangular shape in face view, a base up to 75 μm in length, and a height that was one‐seventh the length of the base. Crystals of various sizes commonly were stacked face‐to‐face with one or more edges coinciding, but removal of organic material by treatment in sodium hypochlorite resulted in disaggregation. The crystals were soluble in dilute hydrochloric acid without effervescence but were insoluble in acetic acid. These diagnostic chemical solubility tests and a positive reaction to the Yasue staining reaction indicated that the crystals were composed of calcium oxalate. Scanning electron microscopy showed that most crystals had smoothly curving edges, but some had truncate or beveled margins. Calcium oxalate crystals have been reported to occur in the large central vacuoles of several bryopsidalean species, but the crystals in C. wilsonis were present in the parietal cytoplasm, which was evident from the presence of crystals in streaming cytoplasm. Calcium oxalate crystals, amyloplasts, chloroplasts, and other cytoplasmic constituents moved along cytoskeletal cables at rates of approximately 2.8 μm s⁻¹. These findings add to a growing body of evidence that calcium oxalate crystals in diverse algae may be present in cellular compartments other than the central vacuole.     

斑龙芋属(天南星科)及近缘属植物的叶表皮形态

光镜、电镜下观察了天南星科天南星族下斑龙芋属2个种及近缘属13个种植物的叶表皮形态特征。实验结果显示,4属植物的叶表皮组成及其形态特征较相似,属间不存在明显差异,但某些特征在种间存在差异,可作为种的鉴别特征。叶表皮特征支持将单籽犁头尖和昆明犁头尖两个种合并为一个种。15个种的气孔器均具有2个副卫细胞,Stebbins andKhush认为这是气孔器类型中较具2个以上副卫细胞更进化的一种类型,而天南星科大多数族的气孔器都具有2个以上的副卫细胞,这也证明了天南星族是天南星科较进化的族。     

Zygotic embryogenesis in Anthurium (Araceae)

Morphological, anatomical, and histochemical aspects of zygotic embryogenesis by Anthurium andraeanum Lind. were investigated from 4 to 24 wk postpollination. Anatomical features were correlated with morphology of the spadix and capacity of embryos to germinate in vitro. Development from a single-cell zygote to fully mature seed takes 24 wk. The suspensor was two ranked and obvious during the early stages of embryogeny. It was apparent by week 8, substantial until week 14, and diminished rapidly until its absence by week 22. Differentiation of the shoot apex, cotyledon, and protoderm occurs at 14 wk. The embryo starts to derive nutrition from the endosperm at this time, and germination of cultured ovules reached 56%. By 20 wk the shoot apex had visible leaf primordia and the root apex was clearly defined. The cotyledon was well developed and surrounded the shoot tip. The storage of protein and starch was at its greatest in the endosperm and embryo. Furthermore, 100% germination of cultured ovules and embryos occurred at 20 wk and thereafter. Fully mature embryos at 24 wk are green and contain protoxylem elements.     

中国不产曲籽芋属植物

曲籽芋属在中国的分布源自对采自海南的一号标本———W.T.Tsang（曾怀德）553=L.U.16052（1927年8月27日采）的错误鉴定。这号标本被E.D.Merrill定名为曲籽芋Cyrtosperma lasioides Griffith,并分藏于国内外的标本馆。因此,《海南植物志》第四卷、《中国植物志》第十三卷第二分册、《中国种子植物科属词典》以及吴征镒的《中国种子植物属的分布区类型》一文等都记录了曲籽芋属。收藏在中国科学院华南植物研究所、英国邱皇家植物园和爱丁堡皇家植物园的W.T.Tsang（     

Crystal types and their distribution in the bark of African genistoid legumes (Fabaceae tribes Sophoreae,Podalyrieae, Crotalarieae and Genisteae)

The occurrence and distribution of seven crystal types in 114 bark samples from 25 genera and 91 species, representing all four tribes of African genistoid legumes, are reported. The seven types are prismatic, druse (including irregular crystal clusters), navicular (including truncated navicular, here reported for the first time), spherical crystal cluster, styloid, crystal sand and acicular crystals in sheaf‐like aggregates. Unlike most studies, the elemental composition of the crystals was examined using X‐ray microanalyses. With the exception of acicular crystals, all crystals showed the typical peaks of calcium (sometimes accompanied by small amounts of magnesium). Acicular crystals in sheaf‐like aggregates were composed only of carbon and oxygen, indicating that they are organic and precipitate during drying or after fixation in alcohol. These crystals are found only in the two early‐diverging lineages of Podalyrieae (Cyclopia and Virgilia+Calpurnia clades), consistent with the phylogenetic pattern in the tribe (indicating a secondary loss). Navicular crystals are restricted to Podalyrieae and Crotalarieae. Prismatic crystals in bark are proposed to be the ancestral condition, with multiple losses (or reversals) in Podalyrieae, Crotalarieae and Genisteae. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 620–632.     

Plant calcium oxalate crystal formation, function, and its impact on human health

Crystals of calcium oxalate have been observed among members from most taxonomic groups of photosynthetic organisms ranging from the smallest algae to the largest trees.The biological roles for calcium...