SIMS Investigation of the Distribution of K + , Na + , Mg 2+ and Ca 2+ Cations in Birch Pollen

Microscopy Res & Technique

Verdus

et al. 2002

In 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.

Section: Sample Preparationmentioning

confidence: 99%

Appraisal of Sims applicability to boron studies in plants

Dérue

Microscopy Res & Technique

Verdus

et al. 2002

“…Conventional techniques based on the chemical fixation of biological samples in aqueous phase are clearly inappropriate. Precipitation methods (Follet-Gueye et al, 1998;Mentré and Escaig, 1988;Mentré and Halpern, 1988) and new methods using vapor-phase fixation-dehydration (Dérue et al, 2002;Follet-Gueye et al, 1999;Lhuissier et al, 1997) have given interesting results with plant samples. Cryomethods can be considered as the most satisfactory sample preparation technique for ion analysis and imaging (Edelmann, 1994;Grignon et al, 1997;Palsgard et al, 1996;Quintana and Bonnet, 1994;Sitte et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

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

Dérue

Microscopy Res & Technique

Demarty

et al. 2006

We 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.

“…However, we had to check for possible interference by 25 MgH 2 − at mass 27, because the mass resolution required to separate it from 12 C 15 N − would be equal to 20 000, a resolution which cannot be attained with an IMS 4f SIMS instrument without a drastic loss of transmittance of the spectrometer. The reason for checking for a possible interference by 25 MgH 2 − is that cytoplasmic structures containing high Mg concentrations are known to exist in pollen grains (Lhuissier et al ., 1997). Using the isotopic‐ratio function of the CAMECA software package, we measured a 15 N percentage value of 0.357 ± 0.009 and (in order to check the reliability of the measurements) a 13 C percentage value of 1.03 ± 0.06 (mean ± standard error of 40 measurements on total, made on four different areas) on the Mg‐phthalocyanine standards.…”

Section: Resultsmentioning

confidence: 99%

“…Pollen fixation and dehydration were carried out at room temperature using a ‘vapour phase’ technique recently developed in our group for studying the distribution of inorganic, mobile ions (Lhuissier et al ., 1997). The technique was used here for the sake of homogeneity of sample preparation (the same specimens were used for imaging the distributions of inorganic ions) and to decrease the risk of losing the NO x molecules possibly attached to diffusible substances.…”

Section: Methodsmentioning

confidence: 99%

“…For the principle of SIMS and recent application to pollen and other plant samples, see for example Thellier et al (1993), De Ârue et al (1999, Grignon et al (1999) and Lhuissier et al (1997Lhuissier et al ( , 1999. Brie¯y, when a ®nely focused ion beam (primary ions) a few keV in energy impinges on the surface of a solid, the most super®cial atomic layers of the solid are sputtered out.…”

Section: Sims Analysesmentioning

confidence: 99%

See 1 more Smart Citation

Secondary ion mass spectrometry imaging of the fixation of ¹⁵N‐labelled NO in pollen grains

Lhuissier

Lefebvre

et al. 2000

Journal of Microscopy

We used secondary ion mass spectrometry to image cellular targets of nitrogen oxides (widespread air pollutants) in pollen grains of birch (Betula verrucosa Ehrh.) and cockfoot (Dactylis glomerata L.). The pollen samples were exposed to air supplemented with high doses of 15NO. The pollen grains were then fixed, dehydrated using a newly developed 'vapour phase' preparation method and embedded in LRW resin. Semithin sections were then analysed. Imaging was performed in scanning mode. As usual, the two isotopes 14N and 15N were imaged as 12C14N- and 12C15N-, respectively. The isotopic percentages of 15N were quantitatively determined either by image processing or by direct analysis. We show that the preferential areas of NO fixation in the pollen cell are the sporoderm and discrete intracytoplasmic structures that we tentatively describe as globoid-like structures similar to those encountered in seeds.