Etude biologique des Propagules de Campylopus introflexus (Hedw.) Brid. sens, restr. (Bryopsida, Dicranales) en relation avec sa dispersion

Campylopus introflexus is a bryophyte species the areal distribution of which is becoming subcosmopolite. The reasons of this extension trend are investigated. In western Europe, C. introflexus produces small vegetative apical shoots (propagules) which separate from the mother plant and give rise to new plantlets. The vegetative reproduction cycles are specified, according to the corresponding potentialities.Campylopus introflexus est une espèce dont l'aire de distribution en expansion devient subcosmopolite. Les causes de son extension sont recherchées. En Europe occidentale, C. introflexus se multiplie par des propagules ayant valeur de rameaux apicaux spécialisés. Les cycles de multiplication végétative par propagules sont précisés et les potentialités correspondantes mises en évidence.Verdus Marie-Claire. Etude biologique des Propagules de Campylopus introflexus (Hedw.) Brid. sens, restr. (Bryopsida, Dicranales) en relation avec sa dispersion. In: Bulletin mensuel de la Société linnéenne de Lyon, 48ᵉ année, n°3, mars 1979. pp. 135-143

Improved protoplast yield and cell wall regeneration in Gracilaria verrucosa (Huds.) Papenfuss (Gracilariales, Rhodophyta)

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SIMS study of the calcium-deprivation step related to epidermal meristem production induced in flax by cold shock or radiation from a GSM telephone

Exposing seedlings of the flax, Linum usitatissimum L., to a variety of weak environmental stresses plus a 2-day calcium deprivation triggers the common response of production of epidermal meristems in the hypocotyl. Here, we show that the same response was induced by a 1 min cold shock. Epidermal meristem production was also induced by a single 2-h exposure to radiation emitted at 0.9 GHz at non-thermal levels by a GSM telephone. This flax-based system is therefore well suited to studying the effects of low intensity stimuli, including those of electromagnetic radiation. To begin to determine the underlying mechanisms, in which calcium is implicated, it is desirable to analyse the changes in ions in the tissues affected. We therefore performed a Secondary Ion Mass Spectrometry (SIMS) study of the distribution of the main inorganic cations in the hypocotyl of control and calcium-deprived seedlings. This showed decreases in calcium, sodium and potassium and an increase in magnesium that did not alter substantially the overall ratio of divalent to monovalent cations

Two-dimensional electrophoresis investigation of short-term response of flax seedlings to cold shock

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Appraisal of Sims applicability to boron studies in plants

International audienceIn the search for a new methodological approach applicable to the determination of the still poorly known primary role of boron in plant physiology, we have undertaken to appraise the potential of the SIMS method for the analytical imaging of the boron isotopes, (10)B and (11)B, at physiological concentrations in plants. With our own, CAMECA IMS4F SIMS ion analyser, and using O(2)(+) as primary ions for the detection of B(+) (plus (12)C(+) and (40)Ca(+)) secondary ions, we have been able to map quantitatively the two boron isotopes in control and boron-enriched plants, to evaluate boron concentrations at the level of individual cells and to determine boron isotopic ratios. This provides the opportunity to carry out the simultaneous labeling and imaging of boron, using enrichment with the stable isotopes, (10)B and (11)B. The method has also the potential for the simultaneous, quantitative detection of the boron isotopes and of the borate-binding sites in plant cells

Dynamic-SIMS imaging and quantification of inorganic ions in frozen-hydrated plant samples

International audienceWe present here SIMS images of the distribution of inorganic cations (Na, K, Mg and Ca) in frozen‐hydrated samples of three plant species, ivy, camomile, and flax. The samples were cryofixed using fast plunge‐freezing. Stigmatic images were obtained, at 100 K, under dynamic SIMS conditions by fast atom bombarding (FAB). Even though the images obtained with the frozen‐hydrated plant samples are still not of upper quality, they show that the method used to prepare these samples preserves existing ionic gradients between the outer and the inner part of the cells, between adjacent cells, including cells with the same type of differentiation, and between tissues. We also describe the quantification of the relative proportions of the ions in the vacuoles of flax. The reasonable accuracy achieved for quantification of the vacuole ion ratios permitted to show (i) that radial gradients of ion ratios in hypocotyls change when the plant is becoming older and (ii) that large differences may exist between adjacent cortical cells of the same type. The role of these substantial differences in vacuole ion balance ratios is a largely unexplored issue in plant physiology

Direct structural identification of polysaccharides from red algae by FTIR microspectrometry I: Localization of agar inGracilaria verrucosa sections

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Chemical Microscopy of Biological Samples by Dynamic Mode Secondary Ion Mass Spectrometry (SIMS)

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Chemical Microscopy of Biological Samples by Dynamic Mode Secondary Ion Mass Spectrometry (SIMS)

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