Water Stress Reveals Effects of Elf Magnetic Fields on the Growth of Seedlings

Abstract

We studied the effects of weak and extremely low-frequency (ELF) magnetic fields (MFs) on the growth of spruce seedlings Picea abies that were exposed simultaneously to stress conditions. The drought environmental stress conditions were simulated by watering the seedlings with polyethylene glycol (PEG) at two different concentrations: 88 and 176 g/L. The experiments showed that a weak, sinusoidal magnetic field (50 Hz, 26 and 105 μT, 12 h/day), which was computer controlled and was generated by a system of Helmholtz-like coils, inhibited the germination and the growth of seedlings, whereas under normal conditions (without PEG), the effects were either zero or stimulatory. When the seeds were soaked in water, the effects of MFs were reversed; i.e., they were stimulatory. This strongly supports some findings that biological systems under stress may demonstrate higher sensitivity to ELF EMFs. Our experiments demonstrate that the inhibition of germination was greater at the greater concentration of PEG (at 105 pT), whereas the growth as well as fresh weight did not show this concentration dependence. Along with well-known frequency and power windows, we suggest physiological windows as well, because even the quality of responsiveness to MFs (i.e., stimulation or inhibition) may strongly depend on the physiological state of organisms.