Medical/biological study (experimental study)

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 med./bio.

By: Roux D, Vian A, Girard S, Bonnet P, Paladian F, Davies E, Ledoigt G

Published in: Planta 2008; 227 (4): 883-891

Aim of study (acc. to author)

To measure rapid molecular responses (i.e. accumulation of stress-related transcripts and cellular energy state) in tomato plants after short-term exposure to radiofrequency electromagnetic fields.

Background/further details

All of the transcripts investigated are wound-up-regulated. Thus, similarities between wounding and radiofrequency electromagnetic field exposure could be studied. Additionally, since two of them encode calcium-binding proteins, the authors examined the effects of varying calcium availability to determine if there was any feedback mechanism involved in their transcription.
ATP concentration and adenylate energy charge were also measured after exposure, as well as the effect of an uncoupling agent on transcript accumulation in order to assess the influence of radiofrequency exposure on cellular energy status and to correlate this with changes in mRNA abundances.

Endpoint

molecular biosynthesis: accumulation of stress-related transcripts (total transcripts for net accumulation and polyribosome-aasociated transcripts for current translation) and cellular energy state

Exposure

- RF

Exposure	Parameters
Exposure 1: 900 MHz Exposure duration: continuous for 10 min	electric field strength: 5 V/m

Exposure 1

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Exposure duration	continuous for 10 min

Exposure setup

Exposure source	MSRC
Chamber	Seeds were grown inside two identical custom-made (plywood) culture chambers with a hydroponic system. One of the chambers was armoured with a multi-layered aluminum material to protect the plants from exposure.
Setup	When the plants were 3 weeks old, the whole culture chamber was placed in the MSRC (24 h prior to irradiation) in a volume where the field was homogeneous and isotropic. The MSRC (mode stirred reverberation chamber) was a large (200 m³) Faraday cage with an RF-EMF that irradiated plants from several directions with different polarizations (due to reflection properties of the MSRC).

Parameters

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	5 V/m	-	-	-	-

Reference articles

Beaubois E et al. (2007): Intercellular communication in plants: evidence for two rapidly transmitted systemic signals generated in response to electromagnetic field stimulation in tomato
Roux D et al. (2006): Electromagnetic fields (900 MHz) evoke consistent molecular responses in tomato plants
Vian A et al. (2006): Microwave irradiation affects gene expression in plants

Exposed system:

plant
tomato (Lycopersicon esculentum Mill.)/VFN8
whole body

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: stress-related mRNA expression (calmodulin, calcium-dependent protein kinase and proteinase inhibitor II; quantitative RT-PCR); Ca²⁺ level; ATP concentration level; adenylate energy charge

Investigated system:

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data provide new evidence supporting the hypothesis that plants perceive and respond to microwave exposure as though it was an injurious treatment. In addition to the rapidity of the response (stress-related mRNA accumulation) and its dependency on the second messenger calcium, the authors observed a strong correlation between all the parameters measured (total and polysomal transcript abundance, ATP concentration and adenylate energy charge.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Ministère délégué à l'Enseignement supérieur et à la Recherche (Ministry of National Education and Research), France

Comments on this article

Roux D et al. (2008): Article Addendum: A possible role for extra-cellular ATP in plant responses to high frequency, low amplitude electromagnetic field

Sharma VP et al. (2010): Cell phone radiations affect early growth of Vigna radiata (mung bean) through biochemical alterations
Chen YP et al. (2009): Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings
Tkalec M et al. (2009): Effects of radiofrequency electromagnetic fields on seed germination and root meristematic cells of Allium cepa L
Sharma VP et al. (2009): Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress
Engelmann JC et al. (2008): Is gene activity in plant cells affected by UMTS-irradiation? A whole genome approach
Tkalec M et al. (2007): Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L
Beaubois E et al. (2007): Intercellular communication in plants: evidence for two rapidly transmitted systemic signals generated in response to electromagnetic field stimulation in tomato
Vian A et al. (2007): Plants Respond to GSM-Like Radiations
Roux D et al. (2006): Electromagnetic fields (900 MHz) evoke consistent molecular responses in tomato plants
Vian A et al. (2006): Microwave irradiation affects gene expression in plants
Tkalec M et al. (2005): Influence of 400, 900, and 1900 MHz electromagnetic fields on Lemna minor growth and peroxidase activity
Tafforeau M et al. (2004): Plant sensitivity to low intensity 105 GHz electromagnetic radiation
Tafforeau M et al. (2002): SIMS Study of the Calciumdeprivation step related to epidermal meristem production induced in flax by cold shock or radiation from a GSM telephone
Selga T et al. (1996): Response of Pinus sylvestris L. needles to electromagnetic fields. Cytological and ultrastructural aspects