Synchrotron-based phase-sensitive imaging of leaves grown from magneto-primed seeds of soybean

Abstract

Experiments were conducted to study the effects of static magnetic fields (SMFs) on the venation network of soybean leaves using the synchrotron-based X-ray micro-imaging technique. The seeds of soybean (Glycine max, variety JS-335) were pretreated with different SMFs from 50 to 300 mT in steps of 50 mT for 1 h. The phase-contrast images obtained showed that, as the strength of the SMF increased, the area, width of the midrib, area of the midrib and minor vein of the middle leaflets of third trifoliate leaves also increased up to the SMF strength of 200 mT (1 h) and decreased thereafter. Quantification of the major conducting vein also showed the differences in the major and minor vein structures of the soybean leaves as compared with control leaves. Further, the phase-retrieval technique has been applied to make the segmentation process easy and to quantify the major and minor veins in the venation network. The width and area of midrib enhancement by pre-treatment with SMF implies an enhancement in the uptake of water, which in turn causes an increased rate of photosynthesis and stomatal conductance.

Use of Synchrotron Phase-Sensitive Imaging for the Investigation of Magnetopriming and Solar UV-Exclusion Impact on Soybean (Glycine max) Leaves

“…For the experiments, the seeds were exposed to SMF treatment of 200 mT for 1 h (MT) on the basis of our previous study on soybeans [ 25 ]. Through the Gauss meter, we can measure the magnetic field generated between the poles.…”

“…The Imaging Beamline (BL-4), Indus-2 synchrotron radiation source [ 40 , 52 ] was used to generate the phase-contrast images. The experimental setup was previously described in [ 25 ].…”

“…Some of the previous studies reported stimulatory effects of SMF treatment on crops including rice, maize, soybean, and sunflower [ 15 , 18 , 19 , 20 , 21 ], whereas the others reported slow development [ 22 ]. It is thus predicted that various plant species respond in different ways to varied frequencies and intensities of the magnetic field [ 23 , 24 , 25 ]. Plants showed reactions to magnetic fields based on the intensity, flux density, and exposure time [ 16 , 25 , 26 ].…”

“…It is thus predicted that various plant species respond in different ways to varied frequencies and intensities of the magnetic field [ 23 , 24 , 25 ]. Plants showed reactions to magnetic fields based on the intensity, flux density, and exposure time [ 16 , 25 , 26 ]. The enhanced germination percentage improved plant growth, photosynthesis and yield were observed due to SMF pre-treatment of seeds as compared to the untreated seeds under non-stress as well as under abiotic stresses such as salt, water, UV-B, and arsenic toxicity [ 8 , 15 , 16 , 17 , 18 , 27 , 28 , 29 ].…”

“…Both magnetic treatment and exclusion of solar UV radiation change plant photosynthetic function which is related to the midrib of the leaf venation. The positive effects of solar UV exclusion and SMF on the leaf venation (midrib width) have been individually studied using synchrotron-based X-ray phase-contrast imaging [ 25 , 40 ]. However, there have been no reports on X-ray imaging of leaf venation to the combination of SMF pre-treatment of seeds and the exclusion of solar UV radiation.…”