24-Epibrassinolide as a Modifier of Antioxidant Activities and Membrane Properties of Wheat Cells in Zearalenone Stress Conditions

Abstract

The mechanism of action of brassinosteroids (BRs) in plant cells under stress has not been fully explained, despite ample evidence of their protective effects. The aim of this study was to investigate the significance of physicochemical properties of cell membranes during an interaction with BRs under stress conditions induced by a mycotoxin zearalenone (ZEA). Experiments were performed in in vitro cultures of wheat cells obtained from immature embryos of tolerant and sensitive genotypes. ZEA added to media (30 µM) accumulated in greater amounts in the cells of sensitive wheat, contrary to BRs, which accumulated in greater amounts by the tolerant genotype when added to media at 0.1 µM. Incorporation of 24-epibrassinolide (EBR) stimulated synthesis of casta-and homocastasterone, that is, endogenous BRs present in wheat cells, and enhanced the content of homocastasterone. When the cultures were supplemented with the mixture of ZEA and EBR, castasterone synthesis was stimulated to a higher degree in cells of the sensitive plant. EBR and ZEA added separately activated antioxidant enzyme systems in both genotypes but with preference for the sensitive one. In the cells treated with ZEA + EBR, the activation was close to that observed for EBR alone. The study discussed also the role of membrane permeability, electrokinetic potential changes, and structural properties of native (plasmalemma) and model (DOPC) monolayers in the mechanism of EBR-induced protection, including the possibility of replacing ZEA absorbed in the membrane lipid layers by BR molecules, independently of the activation of the antioxidant system.

Mitigation of the Impact of Vascular Wilt and Soil Hypoxia on Cape Gooseberry Plants by Foliar Application of Synthetic Elicitors

“…BR decreases vascular wilt severity because it can participate in several physiological processes that activate the defense system (Anwar et al, 2018;Peres et al, 2019). This synthetic elicitor can also be involved in the expression of pathogenesisrelated proteins, which lead to an increase in the resistance to pathogens (Ding et al, 2009b;Filek et al, 2018;Saini et al, 2015). In addition, SA can contribute to the regulation of defense against biotrophic and hemibiotrophic pathogens; it plays a key role in the systemic acquired resistance of plants, the modulation of the hypersensitivity response associated with programmed cell death, the increase in the levels of reactive oxygen species, and the activation of lipid peroxidation (Bernsdorff et al, 2016; Dempsey and Klessig, 2017; Qi et al, 2018).…”

The Role of SV Ion Channels Under the Stress of Mycotoxins Induced in Wheat Cells—Protective Action of Selenium Ions

“…The ZEA presence in cells, at hormonal concentrations, stimulates the flowering induction of plants (Biesaga-Kościleniak and Filek 2010). However, at higher than hormonal amounts, it may stimulate oxidative stress and generation of oxygen radicals, which result in destruction of biologically important molecules, such as proteins, lipids, and DNA (Filek et al 2017(Filek et al , 2018. Thus, searching for substances that reduce this toxin accumulation and diminish the biochemical consequences of its action is of special importance.…”

Manganese protects wheat from the mycotoxin zearalenone and its derivatives

“…The problem of mycotoxin accumulation in the tissues 12 , cells 13 and cellular organelles 14,15 of plants that constitute the basics of human diet has prompted the search for methods that prevent the absorption of these substances. Mycotoxins consumed with food accumulate in animal and human cells 16,17 , act as carcinogens and initiate pathogenic changes in various organs 18,19 .…”

“…The different methods are used for detoxification of mycotoxins including the biological neutralization by microorganisms, mainly bacteria 24–28 , and saccharomyces 29 as well as by physical 30,31 and chemical 32 adsorbents. In our previous works, it was demonstrated the reduced ZEN uptake resulting from both foliar administration and seed soaking in brassinosteroids (24-EBR) – phytohormones naturally occurring in cells, as well as from treatment with selenium ions, the accumulation of which is beneficial under oxidative stress conditions 14,15,33 . We suggested that brassinosteroids, with their hydrophilic-hydrophobic molecular structure similar to ZEN, may bind to the lipid part of the bilayer and displace ZEN from membranes.…”

“…The effects of ZEN and its derivatives in the presence of Mn were verified directly in wheat calli cells cultured in vitro and by precise monitoring of physicochemical changes in model lipid membranes. Wheat calli cells, for which the stressogenic effect of ZEN was described in previous studies 15 , was selected to investigate the effects of mycotoxins on biochemical parameters of natural membranes.…”