Developmental Instability as a Means of Assessing Stress in Plants: A Case Study Using Electromagnetic Fields and Soybeans.

Developmental instability is often assessed using deviations from perfect bilateral symmetry. Here, we review the literature describing previous studies, suggest mechanisms that may account for both the generation and disruption of bilateral symmetry, and examine the influence of electromagnetic fields on the asymmetry of soybean leaves. Leaves from plants under high-voltage power lines generating pulsed magnetic fields of <3 to >50 mG were more asymmetrical for two parameters (the terminal leaflet widths and lateral rachilla lengths) than leaves of plants even 50 or 100 m away from power lines. This asymmetry could not be attributed to either size scaling or measurement error.