Medical/biological study (experimental study)

Microwave Irradiation Affects Gene Expression in Plants med./bio.

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

Published in: Plant Signal Behav 2006; 1 (2): 67-70

Aim of study (acc. to author)

To study the effect of mobile phone intensity microwave irradiation on tomato plant studying the accumulation of a stress-related transcript that responds very rapidly to even small environmental stimulations.

Background/further details

Leaf tissue was collected at various times (0, 5, 15, 30, 60 min.) after the end of exposure.

Endpoint

stress response of tomato

Exposure

- microwaves
- mobile communications

Exposure	Parameters
Exposure 1: 900 MHz Exposure duration: continuous for 10 min	electric field strength: 5 V/m (input amplitude) electric field strength: 3.9 V/m (inside the culture chamber) electric field strength: 0.5 V/m (shielded culture chamber)

Exposure 1

Main characteristics

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

Exposure setup

Exposure source	MSRC
Chamber	The MSRC (mode stirred reverberation chamber) consisted of a large room (200 m³) with a double-layered metal wall, acting as a Faraday cage, a log-periodic antenna, and a rotary stirrer creating different patterns of multiple reflections on the chamber walls, thus randomizing the polarization of the electromagnetic waves. Tomato plants were grown inside EMF-permeable culture chambers. Shielded chambers were enclosed in a polymer mesh covered with an aluminium layer causing 45 dB signal attenuation to protect the plants from exposure.
Setup	When the plants were 3 weeks old, the whole culture chamber was placed in the MSRC (18 h prior to irradiation) in a defined working volume where the field was statistically isotropic and homogeneous.
Additional info	The fourth terminal leaf (exposed and shielded) was collected at various times after exposure (0, 5, 15, 30, and 60 min). Control plants were collected before stimulation.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	5 V/m	-	-	-	input amplitude
electric field strength	3.9 V/m	-	-	-	inside the culture chamber
electric field strength	0.5 V/m	-	-	-	shielded culture chamber

Measurement and calculation details

To verify the isotropy and homogeneity of the EMF, the chamber was excited with single frequency signals varying from 800 to 1000 MHz, and 18 measurements of the three spatial components of the electric field in 8 locations within the culture chamber were made per stirrer rotation for each tested frequency.

Exposed system:

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

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: accumulation of basic leucine-zipper transcription factor (bZIP) mRNA (quantitative RT-PCR)
stress response of tomato (see "molecular biosynthesis")

Investigated system:

DNA/RNA

Time of investigation:

before exposure
after exposure

Main outcome of study (acc. to author)

The data showed that low amplitude, short duration, 900 MHz electromagnetic field evoked the accumulation of the stress-related transcript (mRNA). This accumulation was rapid (peaking 5-15 min after exposure), strong (3.5-fold), and was similar to that evoked by injurious stimuli.
In some experiments, the accumulation began immediately after the end of the exposure, while in others there was a short delay. In all cases, the response was maximal at 5-15 min. after the end of exposure, in some cases declined somewhat at 30 min., but generally remained at high levels until 60 min.

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

Roux D et al. (2011): Human keratinocytes in culture exhibit no response when exposed to short duration, low amplitude, high frequency (900 MHz) electromagnetic fields in a reverberation chamber
Sharma VP et al. (2010): Cell phone radiations affect early growth of Vigna radiata (mung bean) through biochemical alterations
Sharma VP et al. (2009): Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress
Tkalec M et al. (2009): Effects of radiofrequency electromagnetic fields on seed germination and root meristematic cells of Allium cepa L
Roux D et al. (2008): Article Addendum: A possible role for extra-cellular ATP in plant responses to high frequency, low amplitude electromagnetic field
Roux D et al. (2008): 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
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