Some fine structural observations on the rhizome ofDendroligotrichum (Bryophyta)

Summary The underground portion (rhizome) of the gametophytic axis ofD. dendroides bears anatomical resemblances to a triarch dicotyledonous root. The similarities include: 1. an epidermis producing epidermal appendages; 2. a cortex with endodermoid layer; and 3. a tri-radiate arrangement of the food and water-conducting tissue. Histochemical observations reveal that the entire radial and transverse walls of the endodermoid cells are encrusted with amorphous deposits, probably of polyphenolic nature. Casparian bands are not present as reported by earlier workers. The radial walls exhibit a fine structure of alternating electron-dense and electron-opaque lamellae. In plasmolyzed cells the plasmalemma does not adhere to the radial wall. Plasmodesmatal connections were observed in the radial and outer tangential walls of the endodermoid cells, but not in the inner tangential walls. These features of the endodermoid layer ofD. dendroides are discussed in relationship to the structure and function of the endodermis of vascular plants.     

Inhibiteurs anti-trypsine et activités protéolytiques des Albumines de graine de Vigna unguiculata

Summary The extracellular space of tentacles of Drosera capensis L. is divided into two compartments by cuticular material between cells of an endodermoid layer and by the nonporous cuticle of the stalk and neck. The distal compartment includes the mucilaginous secretion as well as the free space of the secretory cap, since the cuticle covering the cap is perforated by numerous 0.05–0.3 m pores. The proximal compartment includes xylem and the intercellular space of the stalk. The existence of the endodermoid partition is consistent with the observation that action potentials recorded extracellularly from the head may be positive-going while those recorded extracellularly from the stalk are negative-going. The partitioning is also consistent with the hypothesis previously proposed to explain why the amplitude of action potentials recorded from the mucilage varies as a function of the amplitude of the receptor potential.The living cells are united by plasmodesmata. Unusually abundant plasmodesmata were observed in the walls between endodermoid cells and neck cells, between neck cells and the next row of outer stalk cells, in the end walls connecting the outer stalk cells, and the end walls connecting the inner stalk cells: these strategically located plasmodesmata presumably permit the electrotonic spread of receptor potentials and action potentials between cells.     

离体蒜苔贮存中薄壁细胞超微结构的变化

离体蒜苔贮存中薄壁细胞逐渐衰老,原生质表现出有序的降解和胞间转移。由细胞内膜产生的自体吞噬泡将细胞器消化。降解的原生质组分通过共质体和质外体两种途径转移,并最终运输至顶端作为珠蒜生长的营养。     

Intra and Inter-Cellular Changes in Constitution during the Development of Laticiferous System in Garlic Scape

Systematic investigations, mainly based on electron microscopy, have been conducted on constitutional changes in the laticifer and its adjoining parenchyma during the development of laticiferous system in garlic scape. The laticiferous system of the scape consists of several layers of articulated unbranched latieifers. About half of them are situated 2–3 cell layers below the epidermis, and the rest scattered throughout the cortex (Fig. 23). Latieifer differentiation starts with a thinning out and vacuolation of the dense protoplasm in the latieifer initials (Fig.2), which is followed by gradual degeneration of nuclei, plastids, endoplasmic reticulum, and dictyosomes; and by a sharp diminution of free ribosomes (Figs.3, 4). Remanent and defective forms of some organelles can still be found in the laticifer at the later stage. In spite of these drawbacks, the differentiating laticifer appears to function actively. Its protoplasm is delimited by a distinct plasmalemma (Figs. 3, 4). Its wall is interspersed with pits inclose spacings, to which most plasmodesmata are confined (Figs. 8, 24). The cell interior is packed with vesicles and mitoehondria (Figs. 4, 11, 15). Structurally, the laticifer seems well adapted to material exchange with the adjoining parenchyma. During the sprouting stage of the scape, the laticifer initials enlarge itself or fuse with each other by lateral wall dissolution to extend the diameter; at the same time, the laticifer elongates at an increasingly rapid rate. As a final result, the laticifer can attain 30–50 times the length and 2–3 times. the diameter of the adjoining parenchyma. The electron-dense material which protrudes into the laticifer initial from the parenchyma may be of lysosomal nature and probably concerned with wall dissolution and intracellular lytic processes in latieifer formation (Figs. 5, 7, 10). An excised garlic scape is employed in the observation of mature laticifers, which is always full of sap and is quite turgid. Once the scape is cut open, sap exudes almost exclusively from the cut end of the laticifers at the periphery, which lasts only some seconds. However, if the scape is left aside for a few days, exudation will again take place at the fresh cut end. Unlike the milky juice of many latex plants, the sap exuded from the garlic scape is watery and slightly turbid. The organic solute content is mainly made up of simple sugar and amino acids. It also contains a small amount of proteins and even protoplasmic fragments. Besides, it is worthy to note that decrease in organic solutes in the exudation is closely connected with the degree of exhaustion of cell contents from the withering scape, which is, as has already been shownm the sole agent of supplying materials required for the formation of apical cloves. All the above facts seem to indicate that there exists a loading and unloading process in the latieifer. Our electron micrographs (Figs. 16, 22) give evidence that vesicular transport through plasmodesmata in the pit field is capable of performing such a process: from the parenchyma to the laticifer in loading and from the latter to the former in unloading. The possible role of the laticifers in garlie scape could be a temporary storage of cell contents released successively from the deteriorating parenchyma. The sap content in the laticifer is in full turgidity as a result of loading, and can be readily drawn by unloading if so required. Transcellular cytosis is a term tentatively given by us to designate intercellular transport of sap, solutes, and macromolecular particles in small vesicles, which are formed and packed in one celt, traverse through plasmodesmata and merge into the other; whereas endo and exoeytosis refer to vesicular transport in a single cell only and to its moving in and out of the cell primarily through the plasma membrane, which also takes active part in the formation and dissolution of the vesicle and in the enclosure and release of its content. Transcellular cytosis was first observed by us in the withering parenchyma of an excised garlic scape; and, in the present case, between the latieifer and parenehyma, both being active functionally. As compared with the early notion that intercellular material transport is primarily carried out by secretion and reabsorption of highly degraded products through plasmalemma, transcellular eytosis appears to be a far more efficient means of translocating prefabricated assortment and well packed cargo from one cell into the other.     

中国厚结猛蚁属(膜翅目:蚁科)十三种蚂蚁的形态测量学研究

【目的】为了探索形态测量学方法在蚁科昆虫分类中的应用价值和我国厚结猛蚁属Pachycondyla种间的系统发育关系,对国内保存有标本的厚结猛蚁属13种进行了形态测量学研究。【方法】选取厚结猛蚁属13种各9个个体进行测量,以体长(TL)、头长(HL)、头宽(HW)、触角柄节长(SL)、前胸背板宽(PW)性状特征及头长宽比(CI)、触角柄节比(SI)共12个度量特征为变量,进行主成分分析和聚类分析。【结果】研究表明,3个主成分在头长、头宽、头长宽比及触角柄节比有较高的载荷值,差异显著。聚类结果显示,13种厚结猛蚁聚成4支:第1支(短背厚结猛蚁P.brevidorsa(Xu)、拟黑厚结猛蚁P.melanaria(Emery)、红足厚结猛蚁P.rufipes(Jerdon)和列氏厚结猛蚁P.leeuwenhoeki(Forel))与第2支(片突厚结猛蚁P.lobocarena Xu、郑氏厚结猛蚁P.zhengi Xu和敏捷厚结猛蚁P.astute Smith)的相似度最高,亲缘关系最近;与第3支(多毛厚结猛蚁P.pilosior(Wheeler)、安南厚结猛蚁P.annamita(Andrè)、邵氏厚结猛蚁P.sauteri(Forel)和爪哇厚结猛蚁P.javana(Mayr))的相似度次之,亲缘关系较远;与第4支(中华厚结猛蚁P.chinensis(Emery)和黄足厚结猛蚁P.luteipes(Mayr))相似度最低,亲缘关系最远。聚类关系与传统分类的结果基本一致:中华厚结猛蚁与黄足厚结猛蚁外部形态特征相似,聚为一支;郑氏厚结猛蚁、敏捷厚结猛蚁、邵氏厚结猛蚁、爪哇厚结猛蚁与片突厚结猛蚁外部形态特征相似,聚为另一支,亲缘关系较近。【结论】研究结果证明形态测量学方法具有很好的应用价值,适用于蚁科昆虫分类研究。     

六斑月瓢虫触角及感觉器扫描电镜观察

[目的] 明确六斑月瓢虫雌雄成虫触角感觉器种类、分布及形态特征。[方法] 利用扫描电子显微镜对六斑月瓢虫雌、雄成虫触角形态及触角感受器超微结构进行观察。[结果] 六斑月瓢虫成虫触角由柄节、梗节和鞭节组成,柄节长度与宽度显著大于梗节长度与宽度;鞭节分为9个亚节,末端3节横向膨大呈锤状。雌雄成虫触角上共有8种感觉器:刺形感觉器(SC)、毛形感觉器(ST)、锥形感觉器(SB)、腔形感觉器(CaS)、钟形感觉器(CS)、哑铃形感觉器(DS)、香肠形感觉器(SS)及B?hm氏鬃毛感觉器(BB)。以毛形感觉器和刺形感觉器分布最广,遍布触角;B?hm氏鬃毛仅存在于触角柄节与梗节;触角鞭节第9亚节顶端密布7种触角感觉器。六斑月瓢虫雌雄成虫触角长度、触角感觉器类型及分布无显著差异。[结论] 六斑月瓢虫成虫触角上共有8种感觉器,其触角可能具有感知机械刺激、识别化学信息素及感受温湿度变化的作用。本研究为进一步了解六斑月瓢虫触角与其行为间的关系提供基础资料。     

Genetic requirements for induction of germination of spores of Bacillus subtilis by Ca(2+)-dipicolinate

Dormant Bacillus subtilis spores can be induced to germinate by nutrients, as well as by nonmetabolizable chemicals, such as a 1:1 chelate of Ca(2+) and dipicolinic acid (DPA). Nutrients bind receptors in the spore, and this binding triggers events in the spore core, including DPA excretion and rehydration, and also activates hydrolysis of the surrounding cortex through mechanisms that are largely unknown. As Ca(2+)-DPA does not require receptors to induce spore germination, we asked if this process utilizes other proteins, such as the putative cortex-lytic enzymes SleB and CwlJ, that are involved in nutrient-induced germination. We found that Ca(2+)-DPA triggers germination by first activating CwlJ-dependent cortex hydrolysis; this mechanism is different from nutrient-induced germination where cortex hydrolysis is not required for the early germination events in the spore core. Nevertheless, since nutrients can induce release of the spore's DPA before cortex hydrolysis, we examined if the DPA excreted from the core acts as a signal to activate CwlJ in the cortex. Indeed, endogenous DPA is required for nutrient-induced CwlJ activation and this requirement was partially remedied by exogenous Ca(2+)-DPA. Our findings thus define a mechanism for Ca(2+)-DPA-induced germination and also provide the first definitive evidence for a signaling pathway that activates cortex hydrolysis in response to nutrients.     

生姜根茎的发育过程及分泌腔的超微结构

为了解生姜(Zingiber officinale Roscoe)根茎的发育过程,在光学显微镜和电子显微镜下对不同发育时期的生姜进行显微和超微结构观察,并对分泌腔的发生发育过程进行了研究。结果表明,幼嫩期的生姜,表皮以内的基本组织可大致分为皮层、拟内皮层和中柱。次生加厚分生组织起源于中柱外侧一些细胞,细胞分裂和体积增大促使生姜发育。薄壁细胞内有大量的淀粉粒且其数量、形状和大小因发育时期而不同。分泌腔广布于生姜中,其发育过程可分为3个阶段:分泌腔原始细胞团形成、分泌腔的发生和成熟分泌腔形成。生姜精油主要在线粒体、质体和细胞质中合成。本研究为生姜药用资源的开发利用提供了理论依据。     

On Arborescence in Gahnia clarkei and Gahnia sieberiana

Specimens of Gahnia sieberiana from Brisbane, Queensland, andof Gahnia clarkei from near Orbost, Victoria, were collectedand examined both morphologically and anatomically. The speciesgrow in wet areas and are of interest because they representthe largest arborescent species known in the Cyperaceae. Stemdiameters up to 120 mm and stems up to 10 m long have been observed.Such long stems tend to be supported by nearby vegetation. Althoughfresh stems are tough and woody, they are brittle. Branchingof the stems is sympodial, and numerous branches are producedby plants growing in exposed habitats. There is less branchingin plants from shaded habitats. Basal shoots may also occur.Adventitious roots develop basally on most plants, but withG. sieberiana, some adventitious roots form near the shoot apexand grow in and around leaf bases. Anatomical features of interestare an endodermoid layer composed of sclereids with elongate,undulated, outer tangential walls that are lignified and suberized,short vessel elements with horizontal to oblique simple perforationplates, and relatively short sclereids surrounding vessel elementsin the vascular bundles. Some vascular bundles are bipolar.The presence of short vessel elements here is in marked contrastto the longer tracheary elements in other arborescent monocotyledons. Arborescence, stem anatomy, Cyperaceae, Gahnia, saw sedge, Monocotyledon, bipolar bundles, morphology, endodermoid layer     

Pollen limitation, seed predation and scape length in Primula farinosa

Floral display and reward production may affect the attractiveness of a plant to a range of interacting animals including pollinators, herbivores, and vectors of pathogenic fungi. The optimal floral phenotype should therefore depend on the relative importance of selection exerted by both mutualistic and antagonistic animals. The perennial, rosette herb Primula farinosa is polymorphic for scape length. Natural populations may include both plants with flowers displayed well above the ground (the long-scaped morph) and those with flowers positioned very close to the ground (the short-scaped morph). In this study, we conducted a field experiment to examine how the relative fitness of the two scape morphs is affected by interactions with pollinators and fruit predators in two different microhabitats (high and low vegetation). As predicted based on the difference in floral display, supplemental hand-pollination showed that fruit initiation was more strongly pollen-limited in the short-scaped than in the long-scaped morph, and that this difference was significantly larger in high than in low vegetation. Moreover, plants with a short scape experienced lower levels of fruit predation than plants with a long scape. Among open-pollinated controls, there was no significant difference in seed output between the two scape morphs. However, among plants receiving supplemental hand-pollination, short-scaped plants produced significantly more seeds than long-scaped plants. The results suggest that the positive and negative effects of a prominent floral display (increased pollination and seed predation, respectively) balance in the study population, but also that the short-scaped morph would have an advantage at higher pollination intensities. Spatial and temporal variation in pollinator activity and seed predation should result in associated variation in the relative fecundity of the two scape morphs.     

离体蒜苔衰老过程中乙烯产生和纤维素酶活力的变化

自Horton和Osborne(1967)报道衰老、脱落中激素和纤维素酶活力相关性以来,许多实验证明,乙烯和纤维素酶与衰老和脱落有密切关系。关颖谦等(1981)指明离体水稻叶片衰老时,纤维素酶的活力     

GLANDULAR LEAF STRUCTURE OF TRIPHYOPHYLLUM PELTATUM (DIONCOPHYLLACEAE): A “FLY-PAPER” INSECT TRAPPER

Certain leaves of Triphyophyllum peltatum (Hutch. & Dalz.) Airy Shaw (Dioncophyllaceae) have an extended, erect midrib covered with stalked and sessile glands exhibiting insect-trapping ability. The stalked glands secrete a sticky, acid mucilage to which numerous insects in various stages of decay were observed adhering. The morphology and anatomy of the glandular leaves were investigated with light and scanning electron microscopy. The midrib and the lamina in the lowermost part of the leaf bear stomata. Those of the midrib are transitional between actinocytic and cyclocytic in type. Parenchyma cells in mature and immature portions of the midrib and in the glands contain numerous crystals and amyloplasts. The anatomy of the stalked and sessile glands is remarkably similar to that of Drosophyllum lusitanicum (L.) Link. (Droseraceae). A distinct cuticle covers the gland head, but no pores are visible. Three distinct layers underlie the cuticle: a definite epidermal layer with irregularly thickened cell walls, and two layers of more loosely arranged cells. A fourth layer, endodermoid in nature with radially thickened cell walls, connects the head and stalk of the stalked glands and the head and midrib parenchyma of the sessile glands. Vascular elements (including helical and scalariform tracheary elements) reach the endodermoid layer. According to recent studies, Triphyophyllum and Drosophyllum have different phylogenetic origins; the morphological and anatomical similarities in the insect-trapping glandular leaves show more support for their convergent evolution rather than for an alliance of the Dioncophyllaceae with the Droseraceae.     

云南鸢尾属一新种

报道了鸢尾属植物一新种,即哈巴鸢尾(Iris habanesis X. D. Dong)。该种以植株矮小,花茎单一不分枝,具鸡冠状附属物与尼泊尔鸢尾不同,同时又以花期花茎长15~20 cm而与高原鸢尾有所不同。     

樟巢螟成虫触角感器的扫描电镜观察

利用扫描电镜观察了樟巢螟Orthaga achatina Butler成虫触角的外部形态、感器类型及其分布。樟巢螟成虫触角由柄节、梗节和分为75～85个亚节的鞭节组成;触角背面被覆鳞片,绝大部分感器位于触角的腹面和侧面。樟巢螟成虫触角上都分布有以下8种感器:毛形感器、刺形感器、腔锥形感器、耳形感器、鳞形感器、栓锥形感器、Bhm氏鬃毛和腔乳头状感器,其中以毛形感器的数目最多,并可分为Ⅰ型和Ⅱ型。除Bhm氏鬃毛外,所有的感器都分布在触角鞭节的网纹区上。感器的类型及其分布位置无性别差异。     

Petaline nectaries in Swietenia macrophylla (Meliaceae): Distribution and structural aspects

There are few anatomical studies of the reproductive organs of Swietenia macrophylla, despite its economic importance. This study aims to describe the structural and ultrastructural organization of the petaline nectaries in mahogany flowers. Flower buds and flowers at anthesis were collected, fixed, and processed for studies under light and electron microscopy. Nectaries occur in the median region of the petal, on the abaxial surface. Nectar is produced at all stages, from the very young buds until anthesis. The nectary presents a uniseriate epidermis, without stomata; intercellular spaces among the epidermal cells are frequent and contiguous to the subcuticular space. The secretory tissue consists of two to five layers of cells, which are rich in organelles. The nectaries lack vasculature, and the secretory tissue is isolated from the petaline mesophyll by an endodermoid layer. In the staminate flowers, the number of nectaries is less than that observed in pistillate ones.     

Gibberellin and auxin signals control scape cell elongation and proliferation in <Emphasis Type="Italic">Agapanthus praecox</Emphasis> ssp. <Emphasis Type="Italic">orientalis</Emphasis>

Plant height is determined by the processes of cell proliferation and elongation. Plant hormones play key roles in a species-dependent manner in these processes. We used paclobutrazol (PAC) at 400 mg·L^-1 in this study to spray Agapanthus praecox ssp. orientalis plants in order to induce dwarf scape (inflorescence stem). Morphological examination showed that PAC reduced scape height by inhibiting the cell elongation by 54.56% and reducing cell proliferation by 10.45% compared to the control. Quantification and immunolocalization of endogenous gibberellins (GAs) and indole-3-acetic acid (IAA) showed that the GA₁, GA₃, and GA₄ levels and the IAA gradient were reduced. Among these hormones, GA4 was the key component of GAs, which decreased 59.51-92.01% compared to the control in scape. The expression of cell wall synthesis related genes cellulose synthase (CESA) and UDP-glucuronic acid decarboxylase (UXS) were upregulated significantly, whereas cell wall loosening gene xyloglucan endotransglucosylase 2 (XET2) was downregulated by 99.99% surprisingly. Correlation analysis suggested GA regulated cell elongation and auxin modulated cell proliferation in Agapanthus scape. Additionally, the accumulation of sugars played roles in cell wall synthesis and cell expansion. These results indicated GA and IAA signals triggered a downstream signaling cascade, controlled cell expansion and proliferation during scape elongation.     

Effects of Undernutrition on Glutamatergic Parameters in Rat Brain

Early restriction of nutrients during the perinatal period has marked repercussions on CNS ontogeny, Leading to impaired functions. This study investigated the effects of pre- and postnatal (up to 75 days) undernutrition (diet: 8% protein; normonourished group: 25% protein) on some glutamatergic and behavioral parameters of rats. Undernutrition reduced: (i) seizures caused by ICV quinolinic acid (QA) administration; (ii) Na-independent [³H]glutamate binding in cell plasma membranes of cerebral cortex, and (ii) basal [³H]glutamate release from synaptosomal preparation. Behavioral parameters related to locomotion, anxiety, or memory were not affected. These results indicate that our model of undernutrition decreased the sensitivity to QA as convulsing agent and point to some putative glutamatergic parameters involved in this effect.     

Spore germination

The germination of dormant spores of Bacillus species is the first crucial step in the return of spores to vegetative growth, and is induced by nutrients and a variety of non-nutrient agents. Nutrient germinants bind to receptors in the spore's inner membrane and this interaction triggers the release of the spore core's huge depot of dipicolinic acid and cations, and replacement of these components by water. These latter events trigger the hydrolysis of the spore's peptidoglycan cortex by either of two redundant enzymes in B. subtilis, and completion of cortex hydrolysis and subsequent germ cell wall expansion allows full spore core hydration and resumption of spore metabolism and macromolecular synthesis.     

Auxin in scapes,flower buds,flowers, and fruits of daffodil (Narcissus pseudonarcissus L.)

Summary Diffusates from flower buds, flower fruits, and scape segments, and extracts of flower stalks of Narcissus pseudonarcissus contain an auxin active in the Avena geo-curvature test. The auxin behaved like indole-3-acetic acid (IAA) in thin-layer chromatography (TLC) with neutral and basic solvents on different adsorbents. After TLC, the auxin of the extracts showed chromogenic reactions identical with those of IAA; in gas-liquid chromatography on two different columns, the purified substance, after methylation, appeared at the retention time of IAA methyl ester. The auxin content of the extracts has been estimated to be equivalent to ca. 10 g IAA kg^–1 fresh weight. Diffusates, collected at the basal end of excised flowering apices and of scape segments at different developmental stages, showed highest auxin activity when collected from old buds and young flowers, and from the basal, rapidly elongating scape regions. The diffusible auxin obtained from scape segments was very likely produced by the segments themselves. Thus, the shoot of Narcissus appears to possess two different sites of auxin production, namely, the apical region represented by the flower bud, the flower or the fruit, and the scape.Abbreviations IAA indole-3-acetic acid - IAA-OMe indole-3-acetic-acid methyl ester - TLC thin-layer chromatography - GLC gas-liquid chromatography     

诸葛菜的研究现状与开发前景

诸葛菜是一种十分珍贵的野生油料作物种源。从农艺性状、种子含油量、菜苔氨基酸含量、食用安全性等方面,概述了诸葛菜的研究现状。并提出了在我国开发诸葛菜系列产品,如：保健食用油、脱水保鲜菜苔、菜汁营养饮料,以及作为饲料添加剂的利用前景。