Die Chondriosomen in der Gonogenese bei Equisetum palustre L.

Ohne ZusammenfassungDer Name Gonogenese wird hier im Anschlu\ an die schon eingebürgerte Terminologie vonLotsy eingeführt. Alle Zellen, die infolge zweier meiotischer Teilungen hervorgehen, ungeachtet ihrer morphologischen Bedeutung, nennt er Gonen. Zum ersten Male wurde die hier vorgeschlagene neue Bezeichnung in meinem Buche Die stofflichen Grundlagen der Vererbung (Russisch 1924) gebraucht.     

Sterol Composition of the Strobilus of Equisetum arvense L.

“Process whey protein” was prepared by heating bovine milk whey protein isolate solution at neutral pH under salt-free conditions. The process whey protein solution, being clear, was heated at various pHs (2.0 to 11.0) and NaCl concentrations (0 to 200 mM), and the turbidity and gel properties of the products were then examined. For comparison, the properties of the whey protein isolate treated under the same conditions were measured. The whey protein isolate formed a transparent gel or sol below pH 3 and above pH 7 at low NaCl concentration after heating, but the process whey protein formed transparent gels and sols over a wider range of pH and NaCl concentrations than those of the whey protein isolate. More elastic, firmer, and denser gels were obtained from the process whey protein than from the whey protein isolate. The process whey protein provides a novel food material with useful properties.     

A hysteretic invertase from Equisetum giganteum L

The invertase from Equisetum giganteum L., a lower vascular sporophytic plant, was purified to chromatographic and electrophoretic homogeneity. The enzyme appears to be a pentamer, M_r 91,000, formed by identical subunits (M_r 18,000). An isoelectric point of 4.5 was found for the protein. The optimum pH was about 4.5 and the preferred substrate is sucrose, K_m=10.4 mM. Glucose and fructose are classical non-competitive (K_i=120 mM) and competitive (K_i=96 mM) inhibitors, respectively. Proteins which behave as activators of the enzyme suppress the inhibitory action of the reaction products. The activation energy of the hydrolytic reaction is 18,000 cal/mol. The outstanding property of the invertase is a hysteretic behavior when the pH changes from 3.05 to 4.5. The lag time is independent of the enzyme concentration suggesting that slow conformational changes are induced by pH variation and not by different polymerization states.     

Influence of shade timing on an Equisetum arvense L. population

Equisetum arvense L. is a perennial pteridophyte that grows in open sites. In Tokyo, the plant has photosynthetic shoots from late March to November. However, in some populations, these shoots are lost before summer because of shading by taller plants. To investigate the contribution of shoots that remain on the plant for a certain duration, in terms of the maintenance of the E.arvense population, tubers were cultivated under different light conditions and the dry weight of growth, photosynthetic rates and respiration rates were measured. Individual growth was simulated on the basis of matter production and its partitioning. Biomass at the start of the next growing season (the initial size) was seriously decreased by shading before July. However, shading after July had little effect on the initial size of the next season plants. Thus, E.arvense can maintain its population if its shoots are retained until summer.     

Sieve-Element Ontogeny in the Aerial Shoot of Equisetum hyemale L.

The aerial shoots of Equisetum hyemale L. var. affine (Engelm.)A. A. Eat. were examined with the electron microscope as partof a continuing study of sieveelement development in the lowervascular plants. Young E. hyemale sieve elements are distinguishablefrom all other cell types within the vascular system by thepresence of refractive spherules, proteinaceous bodies whichdevelop within dilated portions of the endoplasmic reticulum(ER). Details of cell wall thickening differ between protophloemand metaphloem sieve elements. Following cell wall thickeningthe ER increases in quantity and aggregates into stacks. Shortlythereafter, nuclear degeneration is initiated. During the periodof nuclear degeneration some cytoplasmic components-dictyosomes,microtubules and ribosomes-degenerate and disappear, while organellessuch as mitochondria and plastids persist. The latter undergostructural modifications and become parietal in distribution.Eventually the massive quantities of ER are reduced, leavingthe lumen of the cell clear in appearance. At maturity the plasmalemma-linedsieve element contains a parietal network of tubular ER, aswell as mitochondria, plastids, and refractive sphemh At thistime many of the spherules are discharged into the region ofthe wall. Sieveelement pores occur in both lateral and end walls.At maturity many pores are traversed by large numbers of ERmembranes. The metaphloem sieve elements of the mid-internodalregions apparently are sieve-tube members. The connections betweenmature protophloem sieve elements and pericycle cells are associatedwith massive wall thickenings on the pericyclecell side.     

Kaempferol and its glycosides from Equisetum silvaticum L. from the Khanty-Mansi autonomous area

Three flavonoids were isolated from the aerial part of the wood horsetail (Equisetum silvaticum L.); two of them were found for the first time. The compounds were identified as kaempferol, kaempferol 3-O-β-D-galactopyranosyl-7-O-α-L-rhamnopyranoside and kaempferol 3-O-rutinosyl-7-O-L-rhamnopyranoside on the basis of the chemical transformations and IR, UV, ¹H-NMR and mass spectra.     

Autofluorescence of intact Equisetum arvense L. spores during their development

The autofluorescence of horsetail Equisetum arvense spores excited with UV-light of 360-380 nm was studied by microspectrofluorimetry during their development from an individual cell to the formation of a multicellular thallus with the generative organs. The investigation involved the registration of the fluorescence spectra of individual intact developing cells and the measurement of the ratio of cell fluorescence intensities in the blue and red regions of the spectrum. Dry blue-fluorescing microspores showed the maxima at 460 and 530 nm and a small maximum at 680 nm. Thirty minutes after moistening in water, red-fluorescing cells arose among blue-fluorescing microspores, indicating the onset of development. Red fluorescence with a maximum at 680 nm enhanced as cells put off their cover, which brightly fluoresced in the blue region of the spectrum with the main maximum at 460 nm. By estimating the ratio of autofluorescence intensities in the blue region of the spectrum to red lightening of microspores at the first stages of development up to 24 h (in particular, their first division, the formation of nonfluorescencing rhizoid, etc.), nonviable (only blue-lightening) cells were distinguished from viable cells, in which red fluorescence began to prevail. After 25-40 days of development, the gametophyte fluorescing mainly at 680 nm formed male organs, antheridia, with blue-green-fluorescing spermatozoids. Then female generative organs archegonia with the egg cell appeared, which fluoresced blue, whereas the surrounding cells fluoresced red. It was supposed that the lightening in the blue and green regions of the spectrum is due to the presence of phenols, terpenoids, and azulenes, whereas the emission in the red region is associated with the presence of chlorophyll and azulenes. The observation of autofluorescence makes it possible to easily distinguish generative cells without additional staining.     

Sexual behaviour of the genus Equisetum, subgenus Equisetum

Gametophytes of five species of Equisetum that were studied in axenic single spore cultures are initially male or female, and the first antheridia appear on the males before the first arche-gonia on the females. The males never produce archegonia, but the females all produce antheridia later in progressively increasing numbers. The proportions of male and bisexual gametophytes are relatively constant within each species but vary greatly between species. Likewise between species there is great variation in the rate at which females later produce antheridia. Male gametophytes are smaller and grow more slowly than females, but individuals of both sexes live for the same length of time. After prolonged culture, growth rates fall to very low levels and there is necrosis of the older parts of the gametophytes; but sex organs are still produced. Initially female gametophytes have much sexually uncommitted tissue, whereas males are composed almost entirely of antheridial branches. The absence of archegonium formation on males may well be related to this lack of sexually undifferentiated tissue and the fact that the growth of the males is intimately connected with antheridium production.     

The sperm of Equisetum arvense L. I. Ultrastructural and cytochemical studies of nuclear constituents of the ripe sperm

Several ultrastructural cytochemical methods are used to determine the constituents of the ripe nucleus of Equisetum arvense L. They show that: DNA, associated with an arginine-rich histone, is localized in central region of the nucleus; nucleoplasm is reduced to a thin peripheral coat and contains a probably lysine rich histone; RNA is not detectable; non histone proteins form lenticular amounts disposed against the nuclear membrane.     

Three 2-oxoglutarate-dependent dioxygenase activities of Equisetum arvense L. forming flavone and flavonol from (2S)-naringenin

Equisetum arvense L. (Equisetaceae-horsetail) accumulates various flavones and flavonols in infertile shoot. Enzyme assays conducted with crude extracts of the green tissue revealed chalcone synthase activity and also three further activities assigned to flavonoid biosynthesis and identified as flavone synthase I, flavanone 3β-hydroxylase and flavonol synthase. The latter three activities were characterized as soluble, 2-oxoglutarate-dependent dioxygenases by their typical cofactor requirements and peculiar inhibition. Notably, this is the first report of flavone synthase I which had been considered to be restricted solely to species of the Apiaceae from a distant plant taxon.     

Die flavonolglykoside von Equisetum telmateja

Nine kaempferol glycosides, including the hitherto unkown 3-β-d-(6-O-acetylglucoside)-7-β-d-glucoside and 3-β-d-(6-O-acetylglucoside)-7-α-l-rhamnoside, have been isolated from Equisetum telmateja of European origin.     

Development of Stomata in Equisetum

Hitherto published accounts of the development of stomata inEquisetum are conflicting about the sequence of divisions andabout the formation of a sub-stomatal cell from a meristemoid.The present study of the development of stomata in a speciesidentified as E. ramosissimum subspecies ramosissimum supportsthe observations of Strasburger (1867) and Pant and Mehra (1964)on the basis of sections cut in various planes through internodesof the plant.     

UHPLC-MS/MS-GNPS based phytochemical investigation of Equisetum arvense L. And evaluation of cytotoxicity against human melanoma and ovarian cancer cells

Equisetum arvense L. is widely used as a traditional medicine for the management of inflammation and cancer. In the present study, phyto-chemical analysis of E. arvense was carried out and its cytotoxic potential against human melanoma (MDA-MB-435) and ovarian cancer cells (OVCAR3) was evaluated. Phyto-chemical profile of E. arvense methanolic extract and its fractions was established employing UHPLC-MS/MS and Global Natural Product Social molecular networking. Cytotoxic activity was evaluated using absorbance assay (CellTiter-Blue® Cell Viability Assay). Overall, 22 compounds were identified in the crude extract and polarity-based fractions of E. arvense. Flavonoids, flavonoid-O-glycosides and phenolic acids were found to be the major classes of phyto-chemicals. In addition, the crude extract of E. arvense and its fractions were found active against the tested cell lines. The highest anti-cancer activity against OVCAR3 cells was exhibited by the n-hexane fraction. These results indicated that E. arvense is rich in flavonoids and might be used for the development of anti-cancer drugs against melanoma and ovarian cancers.     

Sterols from Equisetum arvense

The sterol fraction of Equisetum arvense L. contains, essentially, the following sterols: beta-sitosterol (60.0%), campesterol (32.9%), isofucosterol (5.9%) and cholesterol (trace amounts). The identification of the compounds has been carried out through NMR and MS, while the corresponding percentage have been desumed from the GLC and HPLC data.     

Ueberwinterte Prothallien von Equisetum

Ohne Zusammenfassung     

Comparative morphology of the gametophytes of the genus Equisetum, subgenus Equisetum

When grown under a variety of axenic conditions gametophytes of E. arvense, E. telmateia, E. sylvaticum, E. palustre , and E. fluviatile are all morphologically distinct. Lamellae from archegonial branches provide several diagnostic features but lamellae associated with antheridia are much less distinct. The archegonia of all five species have two neck canal cells and three tiers of neck cells and are of limited use taxonomically. Although antheridium development is basically similar in all species, during the metamorphosis of the spermatocytes specific differences arise in the shape of the cavity, degree of emergence and the number of opercular cells. A taxonomy of the gametophytes based on antheridium morphology corresponds very closely to the classification of the subgenus Equisetum into three sections based on the coning behaviour of the sporophytes.     

Biomechanics and Functional Anatomy of Hollow Stemmed Sphenopsids: III. Equisetum hyemale

As in Equisetum giganteum, the hollow stem of Equisetum hyemale owes the mechanical stability of the internodes to an outer ring of strengthening tissue (hypodermal sterome) which provides stiffness and strength in the longitudinal direction. In contrast to hollow-stemmed grasses, the hypodermal sterome consists of living cells. The compound inner tissue of the overwintering aerial stem of Equisetum hyemale includes a continuous inner and outer endodermis layer of vital thick-walled cells that have slightly lignified Casparian thickenings. The two endodermis layers provide an inner tension and compression bracing which lend resistance to local buckling. The stress-strain relation in longitudinal tension is biphasic with remarkably high critical strains especially in the upper parts of the stem. Scraping off part of the epidermis with the built-in silicate does not change this behaviour, except in the initial steep part of the curve where the Young's modulus is reduced by 20%. No contribution of the endodermis and the parenchyma could be detected in tension tests of longitudinally-oriented strips. Relaxation experiments reveal viscoelastic behaviour. As with the biphasic stress-strain relation and the critical strains, the viscoelastic properties have largely to be ascribed to the hypodermal sterome.