Low-frequency electromagnetic fields induce a stress effect upon higher plants, as evident by the universal stress signal, alanine

Monselise, Edna Ben-Izhak; Parola, Abraham H.; Kost, Daniel

doi:10.1016/s0006-291x(03)00194-3

Cited by 67 publications

(26 citation statements)

References 64 publications

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“…However, when plants were exposed to SVMF of 0.7 mT at either 100 or 60 Hz, γ -amino butyric acid (GABA) and/or ornithine and alanine were also produced. Of these metabolites, GABA and ornithine are produced (though to a lesser extent) under normal conditions, while alanine is unique to stress conditions (Mayr et al, 2004;Koppitz et al, 2004;Ben-Izhak and Kost, 1998) & see the comprehensive table with 70 stress cases resulting in alanine accumulation in plants, animals and microorganisms, published in (Ben-Izhak et al, 2003).…”

Section: Resultsmentioning

confidence: 99%

“…2) were fed by 15 N-labeled ammonium chloride (30 mM) for 24 h. The plants were exposed (in the dark) to SVMF, 60 and 100 Hz/0.7 mT magnetic field, in the absence or the presence of vitamin C for 24 h, and their 15 NH + 4 assimilation was studied using 15 N-NMR spectroscopy of sonicated plants, as detailed before (Ben-Izhak et al, 2003). 15 N-NMR chemical shift assignments were based on published data and were compared with reference samples of amino acids.…”

Section: Amino Acid Metabolism In Duckweedmentioning

confidence: 99%

“…It seems that alanine accumulation is a universal stress signal in a wide variety of organisms. Evidence of formation of "heat shock proteins" and enhanced protein kinase activity under various stress conditions has been reported widely (see literature survey in (Ben-Izhak et al, 2003). It has recently been proposed that enhanced production and accumulation of specific amino acids precedes this stress activity (Ben-Izhak et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…The second system examined the metabolism of ammonium ions in Spirodela oligorrhiza (Lemnaceae, a small aquatic plant, commonly known as Duckweed), grown in darkness (Fig. 2), in the presence of vitamin C (ascorbic acid) (Ben-Izhak et al, 2003). The accumulation of alanine was specifically followed.…”

Section: Introductionmentioning

confidence: 99%

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Radical Scavengers Suppress Low Frequency EMF Enhanced Proliferation in Cultured Cells and Stress Effects in Higher Plants

et al. 2005

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In previous publications, we reported that sinusoidal varying magnetic fields (SVMF) modify the activity and dynamics of the malignancy marker adenosine deaminase, and enhance the proliferation of chick embryo fibroblasts (CEF). While the SVMF examined by us (50, 60 & 100 Hz / 0.06-0.7 mT) were all below kT, they may have the potential of altering chemical processes in which excited radicals are involved.We tested this hypothesis in two experimental systems: CEF in culture and Spirodela oligorrhiza (Lemnaceae) (a small aquatic plant, commonly known as Duckweed). CEF were exposed to SVMF of 100 Hz/0.7 mT for 24 h. The addition of the exogenous radical scavengers catalase, superoxide dismutase or vitamin E to the cells during exposure significantly suppressed enhancement of cell proliferation caused by the field (by 79, 67 and 82%, respectively, as evaluated by the MTT colorimetric assay). 15 N NMR analysis of Duckweed plants fed by 15 N-labeled ammonium chloride and exposed to SVMF at 60 and 100 Hz/0.7 mT for 24 h, revealed augmented alanine production. Alanine did not accumulate in the absence of SVMF. The addition of vitamin C, a radical scavenger, reduced alanine production by 82%.Exposure to SVMF resulted in specific metabolic stress effects in Duckweed plants and enhanced proliferation of CEF. In both cases, it is suggested that free radicals are involved.Abbreviations: SVMF = sinusoidal varying magnetic fields; CEF = chick embryo fibroblasts; ADA = adenosine deaminase; SOD = superodxide dismutase.

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Section: Resultsmentioning

confidence: 99%

Section: Amino Acid Metabolism In Duckweedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Radical Scavengers Suppress Low Frequency EMF Enhanced Proliferation in Cultured Cells and Stress Effects in Higher Plants

et al. 2005

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“…Numerous studies have showed that alanine production accompanies exposure to a variety of stresses. Ben-Izhak Monselise et al (2003) listed 70 stress cases in plants, animals, and microorganisms leading to alanine accumulation. Among the possible functions of alanine, they cited the stimulatory effect of genes encoding for stress-protein synthesis and the role as a reservoir of pyruvate for biosynthesis.…”

Section: Discussionmentioning

confidence: 99%

Antioxidant defenses preserve membrane transport activity in Chironomus riparius larvae exposed to anoxia

Forcella

Berra

Giacchini

et al. 2007

Arch Insect Biochem Physiol

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Changes in enzyme activities, metabolite concentrations, and membrane transport activity underlying the Chironomus riparius larvae adaptive response to anoxia were investigated. Trehalose, malate, and aspartate degradation and alanine accumulation were recorded. During anoxia exposure, there was a boost of antioxidant defenses as shown by an increase of the specific activity of the enzymes catalase, glutathione-S-transferase, glutathione peroxidase, glutathione-synthase, malic enzyme, and NADP-dependent isocitrate dehydrogenase. The ratio, glutathione reduced over glutathione oxidized, decreased. Except for alanine and catalase, the parameters return to their basal value when larvae are transferred to normoxic conditions. To test whether antioxidant defenses had protective effects on membrane functionality, L-leucine uptake into brush border membrane vesicles and membrane lipid peroxidation was measured. No difference between membranes prepared from larvae exposed to anoxia and control larvae was found. The amino acid alanine, when present inside the vesicles, trans-stimulated leucine uptake. This effect could represent a mechanism to stimulate amino acid uptake and catabolism in vivo when free alanine concentration increases during hypoxic periods.

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Extremely low frequency weak magnetic fields enhance resistance of NN tobacco plants to tobacco mosaic virus and elicit stress‐related biochemical activities

Trebbi

Borghini

Lazzarato

et al. 2006

Bioelectromagnetics

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Increasing evidence has accumulated concerning the biological effects of extremely low frequency magnetic fields (ELF-MFs) in different plant models. In the present study, effects of ELF-MFs in tobacco plants reacting to tobacco mosaic virus (TMV) with a hypersensitive response (HR) were evaluated. Plants were exposed for 8 or 24 h (either before or after TMV inoculation) to a static MF, at either -17 or 13 microT, combined with a 10 Hz sinusoidal MF with different intensities (25.6 or 28.9 microT). The working variables were the area and number of hypersensitive lesions in leaves. Following ELF-MFs exposure, an increased resistance was detected, particularly after an 8-h treatment, as shown by the decrease in lesion area and number. Moreover, two enzyme activities involved in resistance mechanisms were analyzed: ornithine decarboxylase (ODC) and phenylalanine ammonia-lyase (PAL). Uninoculated leaves previously exposed to ELF-MFs in general showed a significant increase relative to controls in ODC and PAL activities, in particular for 13 microT static MF plus 28.9 microT, 10 Hz sinusoidal MF (24 h) treatment. In conclusion, ELF-MFs seem to influence the HR of tobacco to TMV, as shown by the increased resistance and changes in ODC and PAL activities, indicating the reliability of the present plant model in the study of bioelectromagnetic interactions.

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Low-frequency electromagnetic fields induce a stress effect upon higher plants, as evident by the universal stress signal, alanine

Cited by 67 publications

References 64 publications

Radical Scavengers Suppress Low Frequency EMF Enhanced Proliferation in Cultured Cells and Stress Effects in Higher Plants

Radical Scavengers Suppress Low Frequency EMF Enhanced Proliferation in Cultured Cells and Stress Effects in Higher Plants

Antioxidant defenses preserve membrane transport activity in Chironomus riparius larvae exposed to anoxia

Extremely low frequency weak magnetic fields enhance resistance of NN tobacco plants to tobacco mosaic virus and elicit stress‐related biochemical activities

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