Steroids constitute one of the most important groups of compounds of regulatory properties both in the animal and plant kingdom. In plants, steroids such as brassinosteroids or progesterone, by binding to protein receptors in cell membranes, regulate growth and initiate processes leading to increased tolerance to stress conditions. Due to their structural similarities to sterols, these steroids may also directly interact with cellular membranes. Our aim was to determine the changes of the structural parameters of lipid membranes under the influence of hydrophobic steroid compounds, i.e., 24-epibrassinolide (EBR) and its precursor-24-epicastasterone (ECS) and progesterone (PRO). Lipids were isolated from wheat seedlings with different tolerances to frost, grown at low temperatures (5 °C) for 1.5 and 3 weeks (acclimation process). Control plants were cultured continuously at 20 °C. From galactolipids and phospholipids, the main polar lipid fractions, the monolayers were formed, using a technique of Langmuir trough. EBR and ECS were introduced into monolayers, together with lipids, whereas the PRO was dissolved in the aqueous sub-phase upon which the monolayers were spread. Measurements performed at 25 °C and 10 °C showed a significant action of the tested compounds on the physicochemical properties of the monolayers. EBR and PRO increased the area per lipid molecule in monolayers, resulting in formation of more flexible surface structures while the presence of the ECS induced the opposite effect. The influence of the polarity of lipids and steroids on the interactions in the monolayer was discussed. Lipids extracted from the membranes of wheat with the most tolerance to frost were characterized by the highest fatty acid unsaturation and steroids had a relatively weak effect on the parameters of the structure of their monolayers.

• MeSH
• Brassinosteroids chemistry   metabolism   pharmacology   MeSH
• Cell Membrane chemistry   drug effects   MeSH
• Membrane Lipids chemistry   metabolism   MeSH
• Lipid Metabolism drug effects   MeSH
• Cold Temperature MeSH
• Progesterone chemistry   metabolism   pharmacology   MeSH
• Triticum drug effects   growth & development   MeSH
• Seedlings drug effects   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

A proteomic response to cold treatment (4 °C) has been studied in crowns of a frost-tolerant winter wheat cultivar Samanta and a frost-sensitive spring wheat cultivar Sandra after short-term (3 days) and long-term (21 days) cold treatments. Densitometric analysis of 2-D differential in gel electrophoresis (2D-DIGE) gels has resulted in the detection of 386 differentially abundant protein spots, which reveal at least a two-fold change between experimental variants. Of these, 58 representative protein spots have been selected for MALDI-TOF/TOF identification, and 36 proteins have been identified. The identified proteins with an increased relative abundance upon cold in both growth habits include proteins involved in carbohydrate catabolism (glycolysis enzymes), redox metabolism (thioredoxin-dependent peroxidase), chaperones, as well as defense-related proteins (protein revealing similarity to thaumatin). Proteins exhibiting a cold-induced increase in the winter cultivar include proteins involved in regulation of stress response and development (germin E, lectin VER2), while proteins showing a cold-induced increase in the spring cultivar include proteins involved in restoration of cell division and plant growth (eIF5A2, glycine-rich RNA-binding protein, adenine phosphoribosyltransferase). These results provide new insights into cold acclimation in spring and winter wheat at the proteome level and enrich our previous work aimed at phytohormone dynamics in the same plant material.

• MeSH
• Electrophoresis, Gel, Two-Dimensional MeSH
• Principal Component Analysis MeSH
• Analysis of Variance MeSH
• Adaptation, Biological genetics   physiology   MeSH
• Densitometry MeSH
• Species Specificity MeSH
• Stress, Physiological genetics   MeSH
• Cold Temperature * MeSH
• Proteomics MeSH
• Triticum genetics   growth & development   metabolism   MeSH
• Gene Expression Regulation, Plant genetics   physiology   MeSH
• Plant Proteins genetics   metabolism   MeSH
• Cluster Analysis MeSH
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization MeSH
• Computational Biology MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

• MeSH
• Environmental Health MeSH
• Risk Assessment MeSH
• Nitrobenzenes toxicity   adverse effects   MeSH
• Environmental Exposure MeSH

• Conspectus
• Veřejné zdraví a hygiena
• NML Fields
• environmentální vědy
• chemie, klinická chemie
• hygiena
• toxikologie
• NML Publication type
• publikace WHO

• MeSH
• Acclimatization physiology   MeSH
• Adipose Tissue, Brown physiology   MeSH
• Cricetinae MeSH
• Membrane Proteins physiology   MeSH
• Cold Temperature MeSH
• Ouabain pharmacology   MeSH
• GTP-Binding Proteins physiology   MeSH
• Sodium-Potassium-Exchanging ATPase antagonists & inhibitors   physiology   MeSH
• Animals MeSH
• Check Tag
• Cricetinae MeSH
• Animals MeSH
• Publication type
• Comparative Study MeSH