WEAK MAGNETIC FIELD DECREASES HEAT STRESS IN CRESS SEEDLINGS

Abstract

We studied the effects of a weak sinusoidal and extremely-low-frequency (ELF) magnetic field (50 Hz, 100 μT) on the growth of cress seedlings (Lepidium sativum) that were also exposed to heat stress conditions at 40, 42 and 45°C for 40 min. The magnetic field was applied for 12 hr before or after the heat stress. The experiments showed that the magnetic field alleviated the inhibitory effect of the heat stress when applied previously, whereas afterwards, the heat stress or the magnetic field alone did not produce any significant growth effects. The results speak in favor of the findings by some researchers showing that biological systems under mild stress produce protective factors that decrease harmful effects of stronger stress and that, under certain circumstances, an oscillating magnetic field can work as a stress-protective agent.