Effect of pulsed electric field on spontaneous photon emission of corn seedlings under osmotic stress

Abstract: There are many complex physiological and biochemical reactions in the process of crop seed germination, so germinating seeds are very susceptible to environmental changes and have significant changes on the later growth. Using various physical methods to improve crops drought resistance has been one of the important research directions of modern agriculture, and the majority of studies have been focused on the high-voltage electrostatic field. Recent studies showed that the center frequency of corn cell potential fluctuations was in near 1 Hz, the cell potential coupling resonance could be occurred under the action of 1 Hz pulsed electric field, and some key physiological processes such as respiratory metabolism, photosynthesis, stomatal conductance and water uptake could be affected by the extremely low frequency pulsed electric field (ELF-PEF) with 1 Hz. Therefore, the effect of 1 Hz pulsed electric field on crop drought resistance could be greater than the electrostatic field. However, the reports about the effect of the ELF-PEF on crop drought resistance and its mechanism have been very little, and hence the corresponding researches need to be strengthened. Spontaneous photon emission is an important life information. Numerous studies have determined that the spontaneous photon emission from living cells is closely related to some important life processes such as cell metabolism, DNA synthesis, respiration and photosynthesis. The analysis of spontaneous photon emission from living cells could provide a non-invasive optical technology for the study of changes in the cell metabolism and the function of the state, and it has been widely used in the studies of plant reaction to pathogens, flooding, drought, salt stress, herbicides, UV radiation and so on. For the above reasons, after the germinating corn seeds were treated by 1 Hz ELF-PEF and the PEG-6000 solution was used to form physiological drought to corn seedlings, the growth of corn seedlings and spontaneous photon emission under osmotic stress were studied in this paper. The results showed that the promoting effects of 1 Hz ELF-PEF on the growth of corn seedlings were obvious: the fresh qualities of roots and leaves of corn seedling treated by 1 Hz ELF-PEF were higher than the controls under osmotic stress, and the spontaneous photon emissions of embryo, roots and leaves of corn seedlings have been strengthened. According to the changes of spontaneous photon emission from the cell and its biological significance, it has been speculated that the treatment of 1 Hz ELF-PEF on corn seedlings can promote the DNA synthesis reactions and respiratory metabolism in embryo cells of germinating corn under osmotic stress, increase the respiratory metabolism and reactive oxygen in root cells of corn seedlings, and accelerate the photosynthetic electron transport activity and photosynthesis in leaf cells of corn seedlings. This study provides a reference to understand the mechanism about the effect of the ELF-PEF on drought resistance of crop seedlings.