bluuebunny/crossref_metadata_2025_split huggingface dataset:
Touch‐ and Methyl Jasmonate‐induced Lignification in Tendrils of Bryonia dioica Jacq.
Authors: Kaiser Isolde , Engelberth J. , Groth Beate , Weiler E. W. 
Published: February 2014

AbstractThe touch‐induced free coiling response of Bryonia dioica tendrils is accompanied by the differentiation of supporting tissue at the ventral side of the organ, becoming the inner (concave) side of the coiled tendril. As part of this process, the Bianconi plate, a continuous sclerenchyma sheath stretching along the ventral face of the five bicollateral vascular bundles, becomes strongly lignified. During this reaction, the extractable activity of phenylalanine ammonia‐lyase in the tendrils increases four‐ to five‐fold, while the amount of PAL, as demonstrated by immunoblotting, remains unchanged. This touch‐induced process can also be elicited by airborne application of methyl jasmonate. The PAL inhibitor, 2‐aminoindan‐2‐phosphonic acid (AIP) completely inhibits both the touch‐ and methyl jasmonate‐induced deposition of lignin‐like material in the Bianconi plate, but has no effect on coiling. From these results, it can be concluded that the cessation of growth at the ventral side of a free‐coiling tendril is not due to induced lignification but rather, lignification seems to serve the function of increasing the mechanical strength of the coiled tendril.
Geosiphon pyriforme, an Endosymbiotic Association of Fungus and Cyanobacteria: the Spore Structure Resembles that of Arbuscular Mycorrhizal (AM) Fungi
Authors: Schüßler A. , Mollenhauer D. , Schnepf E. , Kluge M. 
Published: February 2014

AbstractThe zygomycete Geosiphon pyriforme is the only known endocyanosis of a fungus. The Nostoc spp. filaments are included in photosynthetically active and nitrogen fixing, multinucleated bladders, which grow on the soil surface. The spores of the fungus are white or slightly brownish. They are about 250 μm in diameter and develop singly on hyphal ends or, less frequently, intercalarly. The wall of the spores consists of a thin innermost layer, a laminated inner layer with a thickness of about 10–13 μm, and an evanescent outer layer. The laminated layer is composed of helicoidally arranged microfibrils, and is separated from the evanescent outer layer by a thin electron‐dense sublayer. Polarisation microscopy indicates the occurrence of chitin. Shape and wall ultrastructure of the Geosiphon spores and their cytoplasm resemble that of Glomus spores, but are different from that of other genera of the Glomales and Endogonales. Germination occurs by a single thick hyphal outgrowth directly through the spore wall. Like various AM forming fungi, Geosiphon pyriforme contains endocytic bacteria‐like organisms, which are not surrounded by a host membrane. Our observations indicate that Geosiphon is a potential AM fungus.
Imaging the K, Mg, Na and Ca Distributions in Flax Seeds using SIMS Microscopy
Authors: Jauneau A. , Ripoll C. , Verdus Marie‐Claire , Lefebvre F. , Demarty M. , Thellier M. 
Published: February 2014

AbstractTaking advantage of the sensitivity, the lateral resolution and the ability of secondary ion mass spectrometry (SIMS) for elemental imaging, we have shown that the main alkaline and alkaline‐earth cations exhibited clear‐cut regionalization in flax seeds. Calcium, and even more magnesium were almost exclusively located within the protein bodies (PBs); and they were practically absent from the tissue areas with no PBs, such as the provascular tissue. By contrast, sodium was almost exclusively located outside the PBs; moreover, most of the seed sodium was in the tissues at the seed periphery (chiefly the teguments). Among the studied cations, potassium was the only one with a non‐negligible concentration both in and outside the PBs.
Blue, Green and Red Fluorescence Signatures and Images of Tobacco Leaves*
Authors: Lang M. , Lichtenthaler H. K. , Sowinska Malgorzata , Summ P. , Heisel Francine 
Published: February 2014

AbstractLaser‐induced fluorescence images of the leaf of an aurea mutant of Nicotiana tabacum were recorded for the blue and green fluorescence at 440 and 520 nm and the red chlorophyll fluorescence at 690 and 735 nm. The results obtained were compared with direct measurements of the fluorescence emission spectra of leaves using a conventional spectrofluorometer. The highest emission of blue (F440) and green fluorescence (F520) within the leaf was found in the leaf veins, particularly the main leaf vein. In contrast, the intercostal fields of leaves, which exhibited the highest chlorophyll content, showed only a very low blue and green fluorescence emission, which was much lower than the red and far‐red chlorophyll fluorescence emission bands (F690 and F735). Correspondingly, the ratio of blue to red leaf fluorescence F440/F690 of upper and lower leaf side was much higher in the leaf veins (values 1.2 to 1.5) than in intercostal fields (values of 0.6 to 0.7). The results also demonstrated that in the intercostal fields the major part of the blue‐green fluorescence was reabsorbed by chlorophylls and carotenoids. A partial reabsorption of the red fluorescence band near 690 nm by leaf chlorophyll took place, but did not affect the far‐red fluorescence band near F735. As a consequence the chlorophyll fluorescence ratio F690/F735 exhibited significantly higher values in the chlorophyll‐poor leaf vein regions (1.7 to 1.8) than in the chlorophyll‐rich intercostal fields (0.8 to 1.3). Imaging spectroscopy of leaves was shown to be much more precise than the screening of fluorescence signatures by conventional fluorometers. It clearly demonstrated that the blue‐green fluorescence and the red chlorophyll fluorescence of leaves exhibit an inverse contrast to each other. The advantage of the fluorescence imaging spectroscopy, which allows the simultaneous screening of the whole leaf surface and distinct parts of it, and its possible application in the detection of stress effects or local damage by insects and pathogens, is discussed.
Compartmentation of Zinc in Roots and Leaves of the Zinc Hyperaccumulator Thlaspi caerulescens J & C Presl
Authors: Vázquez M. D. , Poschenrieder Ch. , Barceló J. , Baker A. J. M. , Hatton P. , Cope G. H. 
Published: February 2014

AbstractThlaspi caerulescens is a metallophyte that is able to hyperaccumulate Zn. In the present study the subcellular compartmentation of Zn was investigated in roots and leaves of this species by means of X‐ray microanalysis.Leaves accumulated higher average Zn concentrations than roots. In roots of plants exposed to 10 μM Zn, Zn concentrations in the apoplast were similar to those in vacuoles, while in plants treated with 100 μM Zn considerably higher Zn concentrations were detected in vacuoles than in the apoplast. In epidermal and sub‐epidermal cells of leaves of plants from both treatments, Zn mainly accumulated in vacuoles and, to a lesser extent, in the apoplast. In vacuoles from plants exposed to 100 μM Zn, high Zn concentrations were associated with variable amounts of P, Ca and K. In leaves, the highest Zn concentrations (13,600 μg g−1 d.m.) were found in globular crystals present in many vacuoles of epidermal and subepidermal cells. Smaller deposits with a variable Zn concentration between 1,000 and 18,300 μg g−1 d.m. were observed in the epidermal and subepidermal cells of roots. Both the high Zn/P element ratios found in the crystals and the absence of Mg indicate that, in contrast to other plant species, myo‐inositol hexaphosphate (phytate) is not the main storage form for Zn in Thlaspi caerulescens.
Fish Poisoning Plants in Africa
Authors: Neuwinger H. D. 
Published: February 2014

AbstractFishing with the aid of plant toxins was formerly very common in tropical Africa. Today this easy method of fishing is still practised in remote areas. The method is simple: the poisonous ingredients are pounded and thrown into a pool or dammed‐up sections of a small river. After a short time the fish begin to rise to the surface and can then readily be taken by hand. The fish can be eaten without health problems. The main active compounds are saponins, rotenoids and diterpene esters. Such biologically active plants are of great interest to scientists of various disciplines. Some of these plants provide important insecticides, many play an important part in traditional medicine and in preparation or arrow poisons.258 fish‐poisoning plants are presented, based on 25 years of field research by the author in tropical Africa and evaluations of herbarium notes. 10–20 per cent of the fishing poisons are probably still unknown. They are spread among 167 plant genera and 60 families. The evaluation shows a clear dominance of the Leguminosae (Caesalpiniaceae, Mimosaceae, Papilionaceae) in the hierarchy of the fish poisoning plants. It is also remarkable that a great proportion are in the Euphorbiaceae.
Elicitation of 2,3‐Dihydroxybenzoic Acid and Ajmalicine in a Catharanthus roseus Suspension Culture*
Authors: Frankmann K. T. , Kauss H. 
Published: February 2014

AbstractAddition of an elicitor preparation from cell walls of Phytophthora megasperma f. sp. glycinea (Pmg elicitor) to a newly established cell suspension culture of Catharanthus roseus induced extracellular free 2,3‐dihydroxybenzoic acid, suggesting its role in pathogen defense. The same substance also accumulated intracellularly in a bound form. Treatment of the crude Pmg elicitor preparation with trypsin abolished elicitor activity, suggesting that the active fraction is proteinaceous. The cells became more sensitive to low but not to elevated elicitor concentrations when they were pretreated with 2,6‐dichloroisonicotinic (DCIA) or 5‐chlorosalicylic (5CSA) acid for about 1 day before addition of the elicitor. This indicates that the elicitor reception/transduction system becomes improved by these compounds known to be related to systemic acquired resistance against plant pathogens. The newly established cell line initially accumulated also the indole alkaloid ajmalicine, a process enhanced by Pmg elicitor. This potency was lost during subculturing for about 1 year and was also not restored by preincubation with DCIA or 5CSA. In contrast, elicitation of 2,3‐dihydroxybenzoic acid synthesis was undiminished, suggesting that the Pmg elicitor perception system was still functioning and not the cause for the decline in elicited indole alkaloid production.
Intracellular Localization of Jasmonate‐Induced Proteins in Barley Leaves
Authors: Hause Bettina , zur Nieden Uta , Lehmann J. , Wasternack C. , Parthier B. 
Published: February 2014

AbstractThe plant growth substance jasmonic acid and its methyl ester (JA‐Me) induce a set of proteins (jasmonate‐induced proteins, JIPs) when applied to leaf segments of barley (Hordeum vulgare L. cv. Salome). Most of these JIPs could be localized within different cell compartments by using a combination of biochemical and histochemical methods. Isolation and purification of various cell organelles of barley mesophyll cells, the separation of their proteins by one‐dimensional polyacrylamide gel electrophoresis and the identification of the major abundant JIPs by Western blot analysis, as well as the immuno‐gold labelling of JIPs in ultrathin sections were performed to localize JIPs intracellularly. JIP‐23 was found to be in vacuoles, peroxisomes, and in the granular parts of the nucleus as well as within the cytoplasm; JIP‐37 was detected in vacuoles and in the nucleoplasm; JIP‐66 is a cytosolic protein. Some less abundant JIPs were also localized within different cell compartments: JIP‐100 was found within the stromal fraction of chloroplasts; JIP‐70 is present in the peroxisome and the nucleus; JIP‐50 and JIP‐6 accumulate in vacuoles. The location of JIP‐66 and JIP‐6 confirms their possible physiological role deduced from molecular analysis of their cDNA.
How to Evolve a Complex Plastid? ‐ A Hypothesis
Authors: Häuber M. M. , Müller S. B. , Speth V. , Maier U.‐G. 
Published: February 2014

AbstractThe evolution of complex plastids in general and the phylogeny of the intermediate forms present in chlorarachniophytes and cryptophytes are considered. By comparing possible protein transport mechanisms in these algae, also taking into account problems in explaining horizontal gene transfer between eukaryotic nuclei, we arrive at the hypothesis that the initial step in the evolution of complex plastids was a primary endocytobiosis of the host (!) cell. Our hypothesis also explains why the nucleomorph (the reduced nucleus of a secondary endocytobiont) is not eliminated.
Coloured Pollen in Cactaceae: a Mimetic Adaptation to Hummingbird‐Pollination?
Authors: Rose Marie‐Jeanette , Barthlott W. 
Published: February 2014

AbstractPollen of 361 species from 71 genera of Cactaceae was investigated for this study of the correlation between pollen colour and the pollination syndrome. 11% of all species studied had red or brown pollen, and nearly all of these species were ornithophilous. This suggests that pollen colour probably is part of the bird‐flower syndrome of Cactaceae. Possibly the red or brown pollen might be a crypto‐mimetic adaptation to the dark coloured bill of the pollinating hummingbird (Trochilidae) and secures safe transport to a receptive stigma without being removed by the bird immediately.The results are discussed against a background of studies encompassing about 900 species from 77 families, which provide further evidence for the proposed adaptive significance of palynological characters.
Specific Transport of Inorganic Phosphate and C3‐ and C6‐Sugar‐Phosphates across the Envelope Membranes of Tomato (Lycopersicon esculentum) Leaf‐Chloroplasts, Tomato Fruit‐Chloroplasts and Fruit‐Chromoplasts
Authors: Schünemann Danja , Borchert Sieglinde 
Published: February 2014

AbstractPlastidial envelope membranes were isolated from tomato (Lycopersicon esculentum) leaves and green and red tomato fruits by isopycnic discontinuous sucrose density gradient centrifugation. Solubilized envelope membrane proteins were reconstituted into liposomes. Transport measurements revealed that the phosphate translocator from tomato leaves transports inorganic phosphate, 3‐phosphoglycerate and triosephosphates. The phosphate translocators of green and red fruit plastids catalyze, in addition to the transport of these substrates, also the transport of glucose‐6‐phosphate, glucose‐1‐phosphate and phosphoenolpyruvate.
Tissue‐ and Cell‐Specific Distribution of Connexin 32‐and Connexin 26‐related Proteins from Vicia faba L.
Authors: Janßen Martina , Hunte Carola , Leineweber Kirsten , Knop Mona , Cramer H. , Traub O. , Schulz Margot 
Published: February 2014

AbstractDifferent tissues (leaf lamina and midveins, epidermis, primary roots, etiolated shoots, hypocotyl, petioles) and protoplasts from mesophyll, guard cells, and petioles of Vicia faba L., obtained from defined developmental stages were analyzed with polyclonal antibodies raised against mouse liver connexins 26 and 32. Immunostaining after treatment with CX 26 antibodies showed two polypeptides of 21 and 16 kD in all tissues examined except for hypocotyl and epidermis. Additionally, a stronger immunoresponse at 40 kD occurred in extracts from leaf material, mesophyll protoplasts, and roots.Incubation with the CX 32 antibodies resulted in an immunoreactive band at 29 kD in mesophyll protoplast samples, and, a very weak band in extracts from leaf material. A 36 kD polypeptide, present in samples prepared from root, etiolated shoots, petioles, and midveins, did not appear in leaf laminas and mesophyll protoplasts. Extracts from guard cells did not show any immunoreactive band. The tissue‐ and cell‐specific distribution of CX 23‐ and CX 26‐related proteins is supposed to reflect diversities in physiological functions together with alterations in plasmodesmatal ultrastructures during development.
Blue Light Reception in Phycomyces: Red Light Sensitization in madC Mutants
Authors: Galland P. , Amon S. , Senger H. , Russo V. E. A. 
Published: February 2014

AbstractSporangiophores of the zygomycete fungus Phycomyces blakesleeanus are sensitive to near UV and blue light. The quantum effectiveness of yellow and red light is more than 6 orders of magnitude below that of near UV or blue light. Phototropism mutants with a defect in the gene madC are about 106 times less sensitive to blue light than the wild type. These mutants respond, however, to yellow and red light when the long wavelength light is given simultaneously with actinic blue light. In the presence of yellow or red light the photogravitropic threshold of madC mutants is lowered about 100‐fold though the yellow and the red light alone are phototropically ineffective. A step‐up of the fluence rate of broad‐band red light (> 600 nm) from 6 × 10−3 to 6W m−2 elicits, in mutant C 148 madC, a transient deceleration of the growth rate. The growth rate of the wild type is not affected by the same treatment. The results are interpreted in terms of a red light absorbing intermediate of the blue light photoreceptor of Phycomyces. The intermediate should be short‐lived in the wild type and should accumulate in madC mutants.
Drought‐induced Short Roots in Arabidopsis thaliana: Structural Characteristics
Authors: Couot‐Gastelier Jeanne , Vartanian Nicole 
Published: February 2014

AbstractIn Arabidopsis thaliana, as in other Brassicaceae species, a progressive drought stress induced changes in root morphogenesis: from a threshold plant water deficit, the new emerging roots remain short, hairless and often take a tuberized shape at their base while drought persists. The organization of these drought‐induced roots was examined in light microscopy in Arabidopsis thaliana, Columbia wild‐type ecotype, and compared to the normal, well‐watered lateral roots. The main structural traits were the absence of elongation zone, the arrest of cell cap expansion, the lack of root hairs (despite epidermal differentiation in trichoblasts and atrichoblasts) and the radial enlargement of epidermal and cortical cells. The early differentiation, close to the short root apex, of large and highly lignified metaxylem elements, the absence of starch accumulation in hypertrophied cortical cells appeared to be characteristic of the species Arabidopsis, as compared to other Brassicaceae. These structural alterations are discussed in terms of drought‐induced changes in gene expression with regard to similar modifications described in root morphogenesis and root hair‐defective Arabidopsis mutants.
Responses of Calcicole and Calcifuge Poaceae Species to Iron‐Limiting Conditions
Authors: Gries D. , Runge M. 
Published: February 2014

AbstractSix differently distributed Poaceae species were compared in order to identify morphological and/or physiological properties that ensure calcicole species but not calcifuge species a sufficient Fe supply on CaCO3 rich soils.When grown at a range of FeEDTA supply from deficient to adequate, the calcicole species had higher Fe productivities and relative yields at low Fe supply than the calcifuges. Specific root surface and Fe uptake requirements were lower in calcicoles than in calcifuges.Root exudation of Fe‐mobilizing compounds was monitored in plants grown either with or without added FeEDTA in hydroponic culture. Under Fe deficiency, typically more than 80% of soluble root exudates of Poaceae are phytosiderophores (Marschner et al., 1989; Römheld, 1987). Maximum exudation rates of Fe mobilizing compounds were 6.6 to 11.5 μmol g−1 root dry wt 2 hr−1 in calcicoles and 0.48 to 1.64 in calcifuges. If Fe requirement is defined as mean Fe uptake rate required for 90 % of the maximal relative growth rate, the exudation rates of Fe mobilizing compounds were at least 11.7 to 31.9 times higher than Fe requirements in calcicoles and 0.38 to 5.36 times higher in calcifuges.Growth response to a precipitated versus a chelated Fe source was determined. The relative ability to grow with Fe(OH)3 precipitate was correlated with the Fe mobilization rate of the species. The present results give evidence for the importance of Fe efficiency in wild plants. Calcicoles are able to live on calcareous soils partly because they produce larger amounts of Fe mobilizing compounds and have lower tissue Fe requirements than calcifuges.
Net Uptake of Sulfate and its Transport to the Shoot in Spinach Plants Fumigated with H2S or SO2: Does Atmospheric Sulfur Affect the “Inter‐Organ” Regulation of Sulfur Nutrition?*
Authors: Herschbach Cornelia , De Kok L. J. , Rennenberg H. 
Published: February 2014

AbstractSpinach plants (Spinacea oleracea L. cv. Estivato) were grown on nutrient solutions under deficient, normal and excess sulfate supply. In both young and mature plants net uptake of sulfate and its transport to the shoot increased with increasing sulfate supply, but both processes proceeded at a higher rate in young as compared to mature plants. The relative sulfate transport, i.e. the relative amount of the sulfate taken up that is transported to the shoot, decreased with increasing sulfate supply. Apparently, net uptake of sulfate is not strictly controlled by the sulfur demand of the shoot, but xylem loading appears to counteract excess transport of sulfate to the shoot.Fumigation with H2S or SO2 reduced net uptake of sulfate by the roots in sulfur‐deficient plants and absolute as well as relative sulfate transport to the shoot independent of the three sulfate levels supplied to the plant. At the same time thiol contents of the shoot and the root were enhanced by fumigation with H2S and SO2. These findings are consistent with the idea that thiols produced in the leaves can mediate demand‐driven control of sulfate uptake by the roots and its transport to the shoot.
The Function of Phloem Connections in Regenerating In Vitro‐Grafts*
Authors: Schöning U. , Kollmann R. 
Published: February 2014

AbstractIn order to answer the question whether functioning phloem connections exist between graft partners, phloem transport has been studied in cultured explant‐grafts after application of 14C‐sucrose and carboxyfluorescein (CF) to the scion. Autografts of Lycopersicon esculentum and Helianthus annuus were investigated at various regeneration periods. Ungrafted internodes served as controls.A segmental analysis was used to determine the tissue distribution of 14C‐sucrose in a graft. The 14C‐profiles obtained show that sucrose translocation across the graft interface started 4 days after grafting and increased later. The observed translocation appears to occur via wound phloem, since at this time the first complete wound‐phloem bridges (shown as files of aniline‐blue‐positive sieve plates) traverse the graft interface. In 7‐d‐old autografts, sucrose transport across the graft interface returned to normal again, as indicated by the distribution of the label. In addition, 14C‐profiles reveal accumulation of label in sink tissues. Here the basal callus of the stock, and temporarily the graft union itself, represent the main sinks for labelled sucrose.Translocation of CF was analyzed in hand sections of the grafts. The beginning of translocation into the stock was confirmed with the dye. Moreover, effective phloem translocation across the graft interface, visualized with CF, could undoubtedly be assigned to wound‐phloem bridges reconnecting the cut vascular bundles of scion and stock. Thus, the function of phloem connections in regenerated in vitro‐grafts is directly shown.