In search for possible targets of radiofrequency electromagnetic fields in plant cells, a whole genome approach was undertaken: cell suspension cultures of Arabidopsis thaliana were exposed for 24 h to a radiofrequency field representing typical microwave exposure in an urban environment.
Arabidopsis thaliana is a model plant for molecular biology.
The hybridization of a total of eight microarrays was performed (four arrays were hybridized with RNA from microwave exposed and another four arrays with RNA from microwave shielded cells). For each array, RNA extracted from one subculture was used for hybridization, resulting in four replicates for each treatment group.
Modulation type: CW
Exposure duration: continuous for 24 h
|electric field strength||174 V/m||average over time||measured||-||-|
|electric field strength||275 V/m||peak value||measured||-||-|
|SAR||2 W/g||peak value||-||cf. remarks||50 ml|
|SAR||0.75 W/g||average over mass||-||cf. remarks||50 ml|
|power density||20 mW/cm²||peak value||-||-||-|
|power density||8 mW/cm²||average over time||-||-||considerably higher than the recommended value for UMTS (s. guideline 1998)|
Overall, the authors conclude that radiofrequency fields used in mobile phone communication have no dramatic effect on the gene activity of plant cells in suspension culture. Only 10 genes displayed an altered transcription level after exposure and the alterations did not exceed a 2.5-fold reduction or increase in gene activity. It is unlikely that these small changes in gene activity of very few genes will have pronounced effects on the physiology of plant cells (especially if compared to other large changes described in published experiments). Besides that 3 of the affected genes are dark-inducible, the functions of the genes do not point to any known responses of plants to environmental stimuli. Additionally, cells of a suspension culture do not resemble autotrophically growing plants in every respect and their responses to radiofrequency fields may differ from those of intact plants.