152

Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

is an important enzyme that plays an active role in amino acid production

in germinating seeds. The water-insoluble storage proteins are hydrolyzed

by endo-proteases and converted into soluble peptides or finally into amino

acids. The higher germination rate under magnetic field exposures would

be correlated with the greater mobilization of reserve food materials due to

greater activity of enzymes namely, α-amylase, protease, and dehydrogenase

in germinating seeds of several crops (Bhardwaj et al., 2012; Bhatnagar &

Deb, 1978; Samani et al., 2013). Though contradictory results regarding the

negative influence of MF on the protease activity on the second and fourth

day of germination in broad beans have also been recorded (Rajendra et al.,

2005). MF treatment has been reported to enhance the activity of cambium

differentiation that leads to the formation of a higher amount of xylem and

phloem tissues, and thereby it improves the water and nutrient absorption

capacity or their transportation through the plant system that ultimately

results in improved plant health (Selim & El-Nady, 2011).

It is also assumed that capability of absorbing magnetic energy by cellular

ions is important for magnetic influence on biological systems. Further, the

ionic changes or their motions and the physiological availability of small

ions in the cell as affected by the specific frequencies and strength of EMFs

would be responsible for the particular biological effects on the plants (Pazur

& Rassadina, 2009). Previously it has been proposed that the interactions

between magnetic field and biological system would involve several possible

mechanisms viz.: (i) cyclotron resonance model; (ii) paramagnetic resonance

model; (iii) interference between the ions and electron at quantum state;

(iv) free radical reactions including other spin mechanisms; (v) compatible

quantum incitement; (vi) biological effects of torsion fields associated with

weak magnetic field; (vii) oscillator models both at classical and quantum

state; (viii) active metastable state of liquid water by biological systems; (ix)

amplifying mechanism through stochastic resonance or other indiscriminate

processes; and (x) phase conversions revealing liquid crystal assembly in

biophysical systems, etc. (Maffei, 2014). However, according to the recent

insights, there are three main types of magneto sensing mechanism, i.e.: (a)

the radical pair mechanism which is an interaction between the magnetic

nucleus and the unpaired electrons of the radicals that results in the breaking

of the symmetry of two electronic spins or the interconversion of the spins

either in antiparallel direction/singlet state or parallel direction/triplet state;

(b) the cyclotron resonance model of ions suggesting that the Larmor

frequencies of the charged particles like ions follow a circular motion in a

perpendicular plane to the external magnetic field; and (c) cryptochromes,