Plant sensitivity to low intensity 105 GHz electromagnetic radiation

Abstract

Exposing seedlings of the flax, Linum usitatissimum L., to a variety of weak environmental stresses followed by a 2 day calcium deprivation, triggers the common response of production of epidermal meristems (actively dividing groups of cells) in the hypocotyl, which is the part of the stem between the root and the cotyledons (the pre-existing leaves in the embryo). This production reaches a plateau of 10-20 meristems after a month in the case of mechanical stimulation and cold shock. Recently, we have shown that radiation from a global system for mobile communication (GSM) telephone also triggers production of meristems with a plateau of around six meristems. Here, we show that a single 2 h exposure to radiation emitted at 105 GHz at non-thermal levels by a Gunn oscillator induces meristem production with kinetics similar to that induced by weak environmental stimuli and radiation from GSM telephone. Bioelectromagnetics 00: 1-5, 2003. ß 2003 Key words: environmental stress; microwaves; flax; meristem; calcium INTRODUCTION Plants are exposed to a variety of natural abiotic and biotic stresses, such as drought, rain, thermal stresses, wind, mechanical contact, pricking by insects, wounds inflicted by phytophages, and infection by pathogens. These stresses generate intracellular signals [Braam and Davis, 1990;Braam et al., 1996;Jonak et al., 1996; Mizoguchi et al., 1997; Meskiene and Hirt, 2000], such as calcium transients [Knight et al., 1991[Knight et al., , 1992[Knight et al., , 1996 Takahashi et al., 1992; Malhó et al., 1998; Plieth et al., 1998; Mithöfer et al., 1999], that lead to modifications of growth rate and/or morphogenesis of the whole plant [Adams, 1924;Jaffe, 1985; Thellier et al., 2000].Our group has developed an experimental system that clearly reveals the effects of environmental stimuli [Verdus et al., 1996[Verdus et al., , 1997. In this system, week-old seedlings of the flax Linum usitatissimum L. var Ariane are subjected to a temporary (typically 2 days) calcium deprivation by replacing the complete growth medium with a calcium-depleted medium. After this depletion the plants are again grown on the complete medium. This results in the production of epidermal meristems in the hypocotyls, typically 10-20 meristems after a month, provided the seedlings have previously undergone an exposure to different stresses or stimuli, such as drought or touch, respectively. In plants, meristems are small groups of actively dividing cells that after differentiation ultimately produce stem or root tissues.The hypocotyl is the part of the stem located between the root and the cotyledons (pre-existing leaves in the embryo). In control experiments designed to minimize these stresses, the mean number of meristems produced per plant is 0 or 1 after subjecting the plants to calcium deprivation.Recent experiments have shown that exposure to radiation emitted from a global system for mobile communication (GSM) telephone followed by calcium deprivation, leads to meristem production in our flax system [Tafforeau et ...

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

“…These depend on a multitude of diVerent (and uncontrolled) factors and are concerned with long-term eVects, thereby lessening the likelihood of a direct cause-eVect relationship (Boice et al 2002;Feychting et al 2005). Plants are rarely used in RF-EMF experiments (Selga and Selga 1996;TaVoreau et al 2002TaVoreau et al , 2004, partly because their very inertia makes the casual observer presume they are insensitive and thus unresponsive to their environment. In fact the opposite is more likely -their inability to escape the environment implies that plants must be able to sense subtle changes and adapt their responses accordingly Ferguson 2004).…”

Pharmacological Evidence for Calcium Involvement in the Long-Term Processing of Abiotic Stimuli in Plants

“…[4][5][6][7][8][9][10][11][12] The response of plants to stimuli involves changes in the level of free calcium in the cytosol and such changes exhibit complex spatio-temporal dynamics. [13][14][15][16][17][18][19][20] Using the model of the induction of epidermal meristems in the hypocotyl of flax seedlings, [7][8][9][10][11] our group has shown that when flax seedlings (a few days in age) were subjected to both an abiotic stimulus and a 1 to 3 day-long depletion of calcium in the nutrient medium, they developed numerous meristems over the following fortnight. [7][8] These abiotic stimuli included a manipulation stimulus, wind, drought stress, cold shock, and low intensity electromagnetic radiation over a wide range of frequencies.…”

Effects of Gsm900 Electromagnetic Fields on Some Parameters of Chlorophyll Fluorescence in Crop Plants Wheat, Maize and Peas

“…Ïðåç ïîñëåäíèòå ãîäèíè íàðàñòâà èíòåðåñúò íà ó÷åíèòå êúì åôåêòèòå íà ÅÌÏ îò ìîáèëíè òåëåôîíè âúðõó ðàñòåíèÿ. Ðåçóëòàòèòå îò ïðîâåäåíèòå èçñëåä-âàíèÿ ïîêàçâàò, ÷å ðàñòåíèÿòà ðåàãèðàò íà òåçè ÅÌÏ êàòî íà ñòðåñîâ ôàêòîð (Beaubois, 2007;Roux, 2008; T. Selga and M.Selga, 1996;Tafforeau, 2004;Tkalec, 2005Tkalec, , 2007Vian, 2006).…”