Dependence of chlorophyll content in leaves from light regime, electromagnetic fields and plant species

The regularity of the distribution of chlorophylls content in a series of 30 cultivated plants and 75 steppe grasses was studied. The increased content of chlorophyll and magnesium in vegetables and grains compared with greens and steppe grasses is associated with more complex genetics of metabolism, which has stages of flowering and fruiting. The chlorophyll content increases with the use of LED phytoirradiators with an emission band coinciding with the first absorption band of chlorophyll. Industrial electromagnetic fields can affect the biosynthesis of pigments in deciduous trees, but cultivated herbaceous plants are not sensitive to them.


Introduction
The productivity of photosynthesis of green plants is determined mainly by their genetics and strongly depends on temperature, nutrient medium and light regime (Polevoj, 1989 [25]; Andrianova and Tarchevskij, 2000 [2]). These factors determine the structure and efficiency of the photosynthetic apparatus of the plant (PSA). The key functional elements of PSA are a and b forms of the chlorophyll (Chl) (Senge et al., 2014 [28]; Kholmanskiy and Smirnov, 2018 [16]) and water, which plays the role of a dynamic matrix and active metabolite (Polevoj, 1989 [25]; Kholmanskiy and Tilov, 2013 [13]; Aksenov, 2004 [1]). Water sensitizes PSA by forming complexes with Mg and chiral centers Chl (Kholmanskiy and Smirnov, 2018 [16]) and other molecules in the composition of PSA (Senge, et al. 2014 [28]; Kholmanskiy, 2016 [14]; Kholmanskiy, 2018 [15]; Zaytseva and Sitanskaya, 2016 [37]). The abnormal thermodynamic properties of water optimize the physics of cold stratification of seeds at a temperature of about 4 °C (Kholmanskiy, 2018 [15]) and minimize the energy of seed germination and photosynthesis in the temperature range 15-25 °C (Polevoj, 1989[25]; Kholmanskiy, 2018 [15]). The photo-and thermophysics of Chl substantially depend on the Mg ion in the center of porphyrin cycle and the electronic nature of substituents in it (Senge, et al. 2014 [28]; Kholmanskiy and Smirnov, 2018 [16]). In principle, chlorophyll can play the role of a marker of the total Mg content in a plant and therefore can be considered an adequate characteristic of the nutritional value of a plant product.
The photochemistry and photophysics of PSA are determined primarily by the electronic structure of the ground and excited electronic states of Chl. A significant difference in the biophysics of chlorophyll Chl a and Chl b (Tyutereva and Ivanova, 2014 [35]) is caused by the replacement of the CH3 group by the electron-acceptor and proton donor groups of CHO in the 7th position of pheofetin ( Fig. 1). In (Frese et al., 2003 [9]; Kholmanskiy and Smirnov, 2018 [16]), the electronic nature of the ground and lower excited states of Chl was attributed to states with charge transfers whose dipoles are oriented along the mutually orthogonal X and Y axes of the Chl molecule. The high dipole moments of the excited states of Chls initiate electron and proton transfers from other PSA components and these reactions can accelerate the kinetics of photochemical reactions in PSA. It was suggested in (Kholmanskiy et al., 2019b [18]) that micropolarization of PSA promotes proton diffusion in leaves and intensifies the extraction of micro and macrocell ions by a plant. Shashurin, 2014 [27]) and an electrostatic vortex field (Therapeutic reel Mishina [33]).

Results and discussion
The empirical data on the content of chlorophylls a and b in cultivated plants and grasses were taken from books and works published by us and other authors. Table 1 shows the total content of Chl a+b (hereinafter [Chl]) and the ratio a/b for raw samples of plant leaves. The determination of [Chl] in the works was carried out according to the methods described in (Lichtenthaler and Buschmann, 2001 [21]). In (Bohn et al, 2014 [3]) [Chl] was determined using liquid chromatography, and the Mg content in Chl was calculated based on its mass fraction of ~2.7% in a and b Chl. In this work, we compared the concentrations of total Mg and Mg in the composition of Chl (Table 2).  For vegetable crops (tomato, cucumber), leaf (lettuce, greens) and steppe grasses their k were: 8.5; 15-20 and 6-7, respectively. At the same time, the proportion of water in raw samples was determined by the ratio (k -1)/k and was equal to: 88%; 93-96% and 85-86%, respectively.   [18]) and 400 W high pressure sodium (SL) and mercury (ML) lamp.
Their emission spectra and the absorption spectrum of Chl are shown in Figure. In some works, the LED composition included a diode emitting in the far-red region of the spectrum (FRt) with a maximum at 730 nm.
Plant species in Table 1 Table 3. The errors in measuring the pigment content in all samples were about 10%.

Table 3. Effect of electromagnetic fields on pigment photosynthesis
From the data of Table 3 it follows that the influence of EMF affects the efficiency of pigment biosynthesis only in a tree. The reason for this may be the elongation of transport communications along which charged mineral elements move from bottom to top, and phytohormones from top to bottom. The electrophysical properties of the sap in the layers of cambium and sapwood of deciduous trees, in contrast to the resin of conifers, contribute to electrotropism (Kholmanskiy, 2009 [12]).

Conclusion
Thus, it was found that the content of chlorophyll and magnesium in the leaves of cultivated plants is significantly higher in fruitful species than in leafy and, especially in steppe grasses. The