Plant Responses to High Frequency Electromagnetic Fields.

Area of Science:

• Plant biology and environmental science.
• Electromagnetic field interactions with biological systems.

Background:

• Increasing environmental presence of high frequency nonionizing electromagnetic fields (HF-EMF).
• Plants' high surface area to volume ratio optimizes environmental interaction.
• HF-EMF exposure elicits plant responses similar to stress treatments.

Purpose of the Study:

• To review exposure devices and physics of EMF-plant interactions.
• To illustrate cellular, molecular, and whole plant responses to HF-EMF.
• To propose HF-EMF as a genuine environmental factor influencing plant metabolism.

Main Methods:

• Identification of main exposure devices (e.g., gigahertz electromagnetic cells, reverberating chambers).
• Review of physics governing EMF interactions with plants.
• Compilation and illustration of observed plant responses at multiple scales.

Main Results:

• Numerous metabolic activities (e.g., ROS metabolism, enzyme activity, chlorophyll content) are modified.
• Gene expression is altered (e.g., calmodulin, proteinase inhibitor).
• Plant growth is reduced (e.g., stem elongation, dry weight) following nonthermal HF-EMF exposure.
• Responses are observed systemically in distant tissues, not just directly exposed areas.

Conclusions:

• Nonionizing HF-EMF is a genuine environmental factor affecting plant metabolism.
• Observed metabolic changes occur systemically and can be nonthermal.
• Long-term impacts of these metabolic changes require further investigation.