Botanical iron minerals: correlation between nanocrystal structure and modes of biological self-assembly

McCLEAN, Richard G.; Schofield, M. A.; Kean, William F.; Sommer, Cynthia V.; Robertson, Donald; Toth, Dick; Gajdardziska‐Josifovska, M.

doi:10.1127/0935-1221/2001/0013-1235

Cited by 48 publications

(23 citation statements)

References 15 publications

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“…In addition to other iron minerals, aggregations of randomly oriented, 1 to 50-nm hematite nanocrystals were extracted from grass samples [5]. These nanocrystals formed the inorganic cores of phytoferritin, and thus can be regarded as products resulting from BCM processes.…”

Section: Discussionmentioning

confidence: 99%

“…Both the biologically controlled mineralization (BCM) of intracellular magnetite [1][2][3] and the biologically-induced mineralization (BIM) of magnetite, goethite, lepidocrocite, ferrihydrite, and other iron oxides [4][5][6][7] have been extensively studied. Magnetite crystals produced through BCM attracted great interest as a potential biomarker both in terrestrial and extraterrestrial materials [8,9].…”

Section: Introductionmentioning

confidence: 99%

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Properties of intracellular magnetite crystals produced by Desulfovibrio magneticus strain RS-1

Pósfai

Moskowitz

Arató

et al. 2006

Earth and Planetary Science Letters

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Desulfovibrio magneticus strain RS-l is an anaerobic sulfate-reducing bacterium. Cells form intracellular nanocrystals of magnetite but are only weakly magnetotactic. In order to understand the unusual magnetic response of this strain, we studied magnetite crystals within cells grown with fumarate and sulfate. Many cells grown under either condition did not form magnetic crystals while others contained only 1 to 18 small (~40 nm) magnetite-containing magnetosomes. Bulk magnetic measurements of whole cells showed a superparamagnetic-like behavior, indicating that many of the magnetite crystals are too small to have a permanent magnetic moment at ambient temperature. The temperature of the Verwey transition is lower (~ 86 K) than of magnetite from other magnetotactic strains, likely indicating partial oxidation of magnetite into maghemite. As a result of the small size and small number of magnetite magnetosomes, the magnetic moments of most cells grown anaerobically with fumarate or sulfate are insufficient for magnetotaxis.In addition to intracellular magnetite, in some cultures another iron oxide, hematite, formed on the surfaces of cells. The hematite grains are embedded in an extracellular polymeric material, indicating that the crystals likely resulted from a biologically induced mineralization process. Although the hematite particles appear to consist of aggregations of many small (5 to 10 nm) grains, the grains have a consensus orientation and thus the whole particle diffracts as a single crystal. The aligned arrangement of nanoparticles within larger clusters may reflect either a templated nucleation of hematite crystallites in an extracellular organic matrix, or result from a self-assembling process during the crystallization of hematite from ferric gels or ferrihydrite.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Properties of intracellular magnetite crystals produced by Desulfovibrio magneticus strain RS-1

Pósfai

Moskowitz

Arató

et al. 2006

Earth and Planetary Science Letters

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“…Correlation has been observed between soil magnetic concentrations (as measured by susceptibility or saturation remanence) and organic carbon (Maher, 1998). Plants can transport iron from deeper soil layers to the surface via leaf litter fall; it is also possible that magnetite, as the inorganic core of plant phytoferritin, may constitute a more direct (but so far unquanti¢ed) source of soil ferrimagnets, of ultra¢ne (1^50 nm) grain size (McClean et al, 2001). Evans and Heller (1994) have noted that the magnetic grain size distributions of the palaeosols spanning the Chinese Loess Plateau appear very similar (as indicated by their magnetic coercivity spectra).…”

Section: Discussionmentioning

confidence: 99%

Magnetic mineralogy of soils across the Russian Steppe: climatic dependence of pedogenic magnetite formation

Maher

Alekseev

Alekseeva

2003

Palaeogeography, Palaeoclimatology, Palaeoecology

187

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Formation of ferrimagnets in well-drained, buffered, unpolluted soils appears to be related to climate, and especially rainfall. If robust, this magnetism/rainfall couple can be used to estimate past rainfall from buried soils, particularly the multiple soils of the Quaternary loess/soil sequences of Central Asia. However, dispute exists regarding the role of climate vs. dust flux for the magnetic properties of modern loessic soils. Here, we examine the mineralogical basis of the magnetism/rainfall link for a climate transect across the loess-mantled Russian steppe, where, critically, dust accumulation is minimal at the present day. Magnetic and independent mineralogical analyses identify in situ formation of ferrimagnets in these grassland soils; increased ferrimagnetic concentrations are associated with higher annual rainfall. XRD and electron microscopy show the soil-formed ferrimagnets are ultrafinegrained ( 6 V50 nm) and pure. Ferrimagnetic contributions to Mo « ssbauer spectra range from 17% in the parent loess to 42% for a subsoil sample from the highest rainfall area. Total iron content varies little but the systematic magnetic increases are accompanied by decreased Fe 2þ content, reflecting increased silicate weathering. For this region, parent materials are loessial deposits, topography is rolling to flat and duration of soil formation effectively constant. The variations in soil magnetic properties thus predominantly reflect climate (and its co-variant, organic activity)ŝ tatistical analysis identifies strongest relationships between rainfall and magnetic susceptibility and anhysteretic remanence. This magnetic response correlates with that of the modern soils across the Chinese Loess Plateau. Such correlation suggests that the rainfall component of the climate system, not dust flux, is a key influence on soil magnetic properties in both these regions. ß

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“…A weak static homogeneous MF (<100 μT), which has a low energy content (Galland and Pazur 2005), is directly connected to magnetotropism in plants (Galland and Pazur 2005, based on seven studies in the literature). This low energy content is not enough for breaking chemical bonds, therefore, Galland and Pazur (2005) discussed three other possible mechanisms based on physical mechanism for the effect of magnets on plant growth beside ferrimagnetism, which is already well proved for bacterial magnetotaxis (Blackmore 1982) and ferrimagnetic crystals, such as magnetite or hematite, was also detected in plants (McClean et al 2001): ion cyclotron resonance (ICR), quantum coherence, and the radical pair models. The ICR model is based on the path of ions in a WMF.…”

Section: Explanation Based On Diamagnetism Paramagnetism Ferromagnementioning

confidence: 99%

Magnetic fields: how is plant growth and development impacted?

2015

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This review provides detailed insight on the effects of magnetic fields on germination, growth, development, and yield of plants focusing on ex vitro growth and development and discussing the possible physiological and biochemical responses. The MFs considered in this review range from the nanoTesla (nT) to geomagnetic levels, up to very strong MFs greater than 15 Tesla (T) and also super-weak MFs (near 0 T). The theoretical bases of the action of MFs on plant growth, which are complex, are not discussed here and thus far, there is limited mathematical background about the action of MFs on plant growth. MFs can positively influence the morphogenesis of several plants which allows them to be used in practical situations. MFs have thus far been shown to modify seed germination and affect seedling growth and development in a wide range of plants, including field, fodder, and industrial crops; cereals and pseudo-cereals; grasses; herbs and medicinal plants; horticultural crops (vegetables, fruits, ornamentals); trees; and model crops. This is important since MFs may constitute a non-residual and non-toxic stimulus. In addition to presenting and summarizing the effects of MFs on plant growth and development, we also provide possible physiological and biochemical explanations for these responses including stress-related responses of plants, explanations based on dia-, para-, and ferromagnetism, oriented movements of substances, and cellular and molecular changes.

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Botanical iron minerals: correlation between nanocrystal structure and modes of biological self-assembly

Cited by 48 publications

References 15 publications

Properties of intracellular magnetite crystals produced by Desulfovibrio magneticus strain RS-1

Properties of intracellular magnetite crystals produced by Desulfovibrio magneticus strain RS-1

Magnetic mineralogy of soils across the Russian Steppe: climatic dependence of pedogenic magnetite formation

Magnetic fields: how is plant growth and development impacted?

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