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Electromagnetic Fields in Biological Systems
magnetically treated chickpea seeds may perform better under rainfed (unirrigated)
conditions where there is a restrictive soil moisture regime.
The same research group (Vashisth and Nagarajan 2010) further investigated the
effect of SMFs (≤250 mT) on the seeds of sunflower (Helianthus annuus). The treatment
of sunflower seeds in these SMFs increased the speed of germination, seedling length,
and seedling dry weight under laboratory germination tests. Of the various treatments,
exposure to 50 and 200 mT for 2 hours yielded the peak performance. The SMF exposure improved seed coat membrane integrity and reduced cellular leakage and electrical
conductivity. Treated seeds when planted in soil resulted in statistically higher seedling dry weight, longer root length, higher root surface area, and higher root volume in
1-month-old seedlings. In germinating seeds, enzyme activities of α-amylase, dehydrogenase, and protease were significantly higher in treated seeds in contrast to controls.
The higher enzyme activity in SMF-treated sunflower seeds was assumed the reason
behind fast germination and early vigor of seedlings.
Cakmak, Dumlupinar, and Erdal (2010) reported the effects of different intensities of
SMFs (4 and 7 mT) on seed germination and seedling growth of bean and wheat seeds
in different media having 0-, 2-, 6-, and 10-atm osmotic pressure prepared with sucrose
or salt. The germination percentages of the treated seeds were compared with those of
untreated seeds germinated in different osmotic pressures during 7-day incubation. The
application of both SMFs promoted the germination ratios of bean and wheat seeds,
regardless of increase in osmotic pressure of sucrose or salt. Growth data measured on the
seventh day showed that the treated plants grew faster than control. After 7 days of incubation, the mean length of treated seedlings was found to be statistically higher than that
of control plants in all the media considered. The greatest germination and growth rates
in both plants were found in the 7-mT-exposed group. Effects of SMF on germination
and growth increased positively with increasing osmotic pressure or salt stress compared
with their respective controls. In contrast, SMF caused an increase in the dry biomass
accumulation of roots and shoots of both bean and wheat seedlings; however, this effect
was found statistically significant in all conditions for wheat but not for bean, in general.
Huang and Wang (2008) assessed the effect of ELF-EMFs on the early growth of plants
using mung beans. Sinusoidal pulsed-width modulation (SPWM) voltages with different fundamental frequencies (10–60 Hz) were set for this purpose. The results indicated
that the ELF-EMF induced by a 20- or 60 Hz SPWM voltage has an enhancing effect on
the early growth of mung beans, whereas the ELF-EMF induced by SPWM voltages of
other frequencies (30–50 Hz) have an inhibitory effect especially at 50 Hz.
Zaporozhan and Ponomarenko (2010) proposed a theory that magnetic fields induce
definite genetic effects due to the existence of magnetic field–sensitive transcription factor repressors capable of regulating the biological activity of organisms through epigenetic mechanisms. These substances are proteins of the CRY/photolyase family. Valuable
information regarding the magnetosensitivity of CRY and its biological responses to
weak magnetic fields was obtained with the plant model Arabidopsis thaliana (Ahmad
et al. 2007). If plants for which magnetic responses have no apparent function are sensitive to external magnetic fields, it is conceivable that other CRY-containing species are
also sensitive to such fields (Harris et al. 2009). The most recent scheme concerning magnetic field effects on CRY activity is that the FADH-access cavity of the helical domain is
Electromagnetic Fields in Biological Systems
magnetically treated chickpea seeds may perform better under rainfed (unirrigated)
conditions where there is a restrictive soil moisture regime.
The same research group (Vashisth and Nagarajan 2010) further investigated the
effect of SMFs (≤250 mT) on the seeds of sunflower (Helianthus annuus). The treatment
of sunflower seeds in these SMFs increased the speed of germination, seedling length,
and seedling dry weight under laboratory germination tests. Of the various treatments,
exposure to 50 and 200 mT for 2 hours yielded the peak performance. The SMF exposure improved seed coat membrane integrity and reduced cellular leakage and electrical
conductivity. Treated seeds when planted in soil resulted in statistically higher seedling dry weight, longer root length, higher root surface area, and higher root volume in
1-month-old seedlings. In germinating seeds, enzyme activities of α-amylase, dehydrogenase, and protease were significantly higher in treated seeds in contrast to controls.
The higher enzyme activity in SMF-treated sunflower seeds was assumed the reason
behind fast germination and early vigor of seedlings.
Cakmak, Dumlupinar, and Erdal (2010) reported the effects of different intensities of
SMFs (4 and 7 mT) on seed germination and seedling growth of bean and wheat seeds
in different media having 0-, 2-, 6-, and 10-atm osmotic pressure prepared with sucrose
or salt. The germination percentages of the treated seeds were compared with those of
untreated seeds germinated in different osmotic pressures during 7-day incubation. The
application of both SMFs promoted the germination ratios of bean and wheat seeds,
regardless of increase in osmotic pressure of sucrose or salt. Growth data measured on the
seventh day showed that the treated plants grew faster than control. After 7 days of incubation, the mean length of treated seedlings was found to be statistically higher than that
of control plants in all the media considered. The greatest germination and growth rates
in both plants were found in the 7-mT-exposed group. Effects of SMF on germination
and growth increased positively with increasing osmotic pressure or salt stress compared
with their respective controls. In contrast, SMF caused an increase in the dry biomass
accumulation of roots and shoots of both bean and wheat seedlings; however, this effect
was found statistically significant in all conditions for wheat but not for bean, in general.
Huang and Wang (2008) assessed the effect of ELF-EMFs on the early growth of plants
using mung beans. Sinusoidal pulsed-width modulation (SPWM) voltages with different fundamental frequencies (10–60 Hz) were set for this purpose. The results indicated
that the ELF-EMF induced by a 20- or 60 Hz SPWM voltage has an enhancing effect on
the early growth of mung beans, whereas the ELF-EMF induced by SPWM voltages of
other frequencies (30–50 Hz) have an inhibitory effect especially at 50 Hz.
Zaporozhan and Ponomarenko (2010) proposed a theory that magnetic fields induce
definite genetic effects due to the existence of magnetic field–sensitive transcription factor repressors capable of regulating the biological activity of organisms through epigenetic mechanisms. These substances are proteins of the CRY/photolyase family. Valuable
information regarding the magnetosensitivity of CRY and its biological responses to
weak magnetic fields was obtained with the plant model Arabidopsis thaliana (Ahmad
et al. 2007). If plants for which magnetic responses have no apparent function are sensitive to external magnetic fields, it is conceivable that other CRY-containing species are
also sensitive to such fields (Harris et al. 2009). The most recent scheme concerning magnetic field effects on CRY activity is that the FADH-access cavity of the helical domain is