High frequency (900 MHz) low amplitude (5 V m−1) electromagnetic field: a genuine environmental stimulus that affects transcription, translation, calcium and energy charge in tomato

Abstract

Using an especially-designed facility, the Mode Stirred Reverberation Chamber, we exposed tomato plants (Lycopersicon esculentum Mill. VFN8) to low level (900 MHz, 5 V m(-1)) electromagnetic fields for a short period (10 min) and measured changes in abundance of three specific mRNA soon after exposure. Within minutes of electromagnetic stimulation, stress-related mRNA (calmodulin, calcium-dependent protein kinase and proteinase inhibitor) accumulated in a rapid, large and 3-phase manner typical of an environmental stress response. Accumulation of these transcripts into the polysomal RNA also took place (indicating that the encoded proteins were translated) but was delayed (indicating that newly-synthesized mRNA was not immediately recruited into polysomes). Transcript accumulation was maximal at normal Ca(2+) levels and was depressed at higher Ca(2+), especially for those encoding calcium-binding proteins. Removal of Ca(2+) (by addition of chelating agents or Ca(2+) channel blocker) led to total suppression of mRNA accumulation. Finally, 30 min after the electromagnetic treatment, ATP concentration and adenylate energy charge were transiently decreased, while transcript accumulation was totally prevented by application of the uncoupling reagent, CCCP. These responses occur very soon after exposure, strongly suggesting that they are the direct consequence of application of radio-frequency fields and their similarities to wound responses strongly suggests that this radiation is perceived by plants as an injurious stimulus.

Human keratinocytes in culture exhibit no response when exposed to short duration, low amplitude, high frequency (900 MHz) electromagnetic fields in a reverberation chamber

“…Previous work from our group demonstrated an unequivocal link between low amplitude, short duration HF EMF exposure and stress-related mRNA accumulation in tomato plants [Roux et al, , 2008Vian et al, 2006;Beaubois et al, 2007], which showed very similar characteristics to those observed after injurious treatments [Vian et al, 1999]. We proposed that plants, especially leaves, have an architecture (planar surfaces) designed to maximize acquisition of matter (gases), energy (sunlight), and information (e.g., EMF) from their environment .…”

“…Using tomato plants as a model system and a mode stirred reverberation chamber (MSRC) as the facility for exposing them to defined doses of HF EMF, our group recently pointed out that a short (10 min), high frequency (900 MHz), low amplitude (5 V/m) EMF exposure caused rapid (15 min), transient and strong (4.5-fold) increases of at least 5 stressrelated transcripts (bZIP transcription factor, calmodulin, calcium-dependant protein kinase, chloroplast mRNA binding protein and proteinase inhibitor 2) Vian et al, 2006]. The EMF exposure was also followed by a large decrease (40%) in ATP content [Roux et al, 2008]. These responses were highly dependent on physiological levels of Ca 2þ and were totally prevented by treatment with calcium-counteracting drugs.…”

Mode Stirred Reverberation Chamber (Msrc): A Large and Efficient Tool to Lead High Frequency Bioelectromagnetic in Vitro Experimentation

“…Although the research programs concerned by in vitro experiments led under investigation various types of exposure systems [16], the MSRC were very seldom used [2]. Previously, we identified a formal link between an electromagnetic environment (900 MHz) and the response of a plant model [17][18][19][20] from MSRC experiments. However, the interest of this exposure device for in vitro experiments is highlighted here in the case of human skin cells in culture.…”

Effects of Prolonged Exposure to Gsm900 Electromagnetic Fields on Enzyme Activity in Leaves of Peas (Pisum Sativum L.)

“…VFN8) ñà ïîëó÷åíè äîêàçàòåëñòâà, ÷å òå âúçïðèåìàò è ðåàãèðàò íà ÅÌÏ êàòî íà óâðåaeäàíå (íàðàíÿâàíå). Âèñîêî-÷åñòîòíîòî ÅÌÏ å ñòèìóë, êîéòî ïîâëèÿâà ãåííàòà åêñïðåñèÿ, òðàíñêðèïöèÿòà, òðàíñëàöèÿòà, êàêòî è íèâàòà íà êàëöèé è åíåðãèéíèÿ áàëàíñ íà äîìàòåíèòå ðàñòåíèÿ [Beaubois, 2007;Roux, 2008;Vian, 2006].…”