Abstract
Plants have developed various acclimation strategies in order to counteract the negative effects of abiotic stresses (including temperature stress), and biological membranes are important elements in these strategies. Brassinosteroids (BR) are plant steroid hormones that regulate plant growth and development and modulate their reaction against many environmental stresses including temperature stress, but their role in modifying the properties of the biological membrane is poorly known. In this paper, we characterise the molecular dynamics of chloroplast membranes that had been isolated from wild-type and a BR-deficient barley mutant that had been acclimated to low and high temperatures in order to enrich the knowledge about the role of BR as regulators of the dynamics of the photosynthetic membranes. The molecular dynamics of the membranes was investigated using electron paramagnetic resonance (EPR) spectroscopy in both a hydrophilic and hydrophobic area of the membranes. The content of BR was determined, and other important membrane components that affect their molecular dynamics such as chlorophylls, carotenoids and fatty acids in these membranes were also determined. The chloroplast membranes of the BR-mutant had a higher degree of rigidification than the membranes of the wild type. In the hydrophilic area, the most visible differences were observed in plants that had been grown at 20 °C, whereas in the hydrophobic core, they were visible at both 20 and 5 °C. There were no differences in the molecular dynamics of the studied membranes in the chloroplast membranes that had been isolated from plants that had been grown at 27 °C. The role of BR in regulating the molecular dynamics of the photosynthetic membranes will be discussed against the background of an analysis of the photosynthetic pigments and fatty acid composition in the chloroplasts.
Highlights
IntroductionTemperature stress is a global problem that mainly causes a decrease in the yield of most crop plants in agriculture and horticulture [1,2]
Among the abiotic stresses, temperature stress is a global problem that mainly causes a decrease in the yield of most crop plants in agriculture and horticulture [1,2]
Bearing in mind the role of membranes as the first cellular line to react to changing temperatures, the aim of the study was to broaden the knowledge about the changes in the molecular dynamics of the chloroplast membranes during the acclimation of a plant to extreme temperatures and the influence of BR on these properties
Summary
Temperature stress is a global problem that mainly causes a decrease in the yield of most crop plants in agriculture and horticulture [1,2]. Some cereal species are sensitive to cold (maize), while other species (winter wheat) are sensitive to low temperatures, especially when there is poor snow cover on fields, which causes frost injuries that lower the yield. Biomolecules 2021, 11, 27 dangerous to plants when there is a water deficit in the summer vegetation season, which has increasingly happened in recent years due to climate changes. Among the plant strategies for counteracting the negative effects of abiotic stresses (including extreme temperatures) [3], biological membranes are an important element. The membrane properties can be altered by incorporating various components into their structure, such as tocopherols, sterols, steroids [5], or carotenoids [6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
