Accumulation of dehydrin-like proteins in the mitochondria of cereals in response to cold, freezing, drought and ABA treatment

BACKGROUND: Dehydrins are known as Group II late embryogenesis abundant proteins. Their high hydrophilicity and thermostability suggest that they may be structure stabilizers with detergent and chaperone-like properties. They are localised in the nucleus, cytoplasm, and plasma membrane. We have recently found putative dehydrins in the mitochondria of some cereals in response to cold. It is not known whether dehydrin-like proteins accumulate in plant mitochondria in response to stimuli other than cold stress. RESULTS: We have found five putative dehydrins in the mitochondria of winter wheat, rye and maize seedlings. Two of these polypeptides had the same molecular masses in all three species (63 and 52 kD) and were thermostable. Drought, freezing, cold, and exogenous ABA treatment led to higher accumulation of dehydrin-like protein (dlp) 63 kD in the rye and wheat mitochondria. Protein 52 kD was induced by cold adaptation and ABA. Some accumulation of these proteins in the maize mitochondria was found after cold exposition only. The other three proteins appeared to be heat-sensitive and were either slightly induced or not induced at all by all treatments used. CONCLUSIONS: We have found that, not only cold, but also drought, freezing and exogenous ABA treatment result in accumulation of the thermostable dehydrins in plant mitochondria. Most cryotolerant species such as wheat and rye accumulate more heat-stable dehydrins than cryosensitive species such as maize. It has been supposed that their function is to stabilize proteins in the membrane or in the matrix. Heat-sensitive putative dehydrins probably are not involved in the stress reaction and adaptation of plants

Influence of CSP 310 and CSP 310-like proteins from cereals on mitochondrial energetic activity and lipid peroxidation in vitro and in vivo

BACKGROUND: The development of chilling and freezing injury symptoms in plants is known to frequently coincide with peroxidation of free fatty acids. Mitochondria are one of the major sources of reactive oxygen species during cold stress. Recently it has been suggested that uncoupling of oxidation and phosphorylation in mitochondria during oxidative stress can decrease ROS formation by mitochondrial respiratory chain generation. At the same time, it is known that plant uncoupling mitochondrial protein (PUMP) and other UCP-like proteins are not the only uncoupling system in plant mitochondria. All plants have cyanide-resistant oxidase (AOX) whose activation causes an uncoupling of respiration and oxidative phosphorylation. Recently it has been found that in cereals, cold stress protein CSP 310 exists, and that this causes uncoupling of oxidation and phosphorylation in mitochondria. RESULTS: We studied the effects of CSP 310-like native cytoplasmic proteins from a number of cereal species (winter rye, winter wheat, Elymus and maize) on the energetic activity of winter wheat mitochondria. This showed that only CSP 310 (cold shock protein with molecular weight 310 kD) caused a significant increase of non-phosphorylative respiration. CSP 310-like proteins of other cereals studied did not have any significant influence on mitochondrial energetic activity. It was found that among CSP 310-like proteins only CSP 310 had prooxidant activity. At the same time, Elymus CSP 310-like proteins have antioxidant activity. The study of an influence of infiltration by different plant uncoupling system activators (pyruvate, which activates AOX, and linoleic acid which is a substrate and activator for PUMP and CSP 310) showed that all of these decreased lipid peroxidation during cold stress. CONCLUSIONS: Different influence of CSP 310-like proteins on mitochondrial energetic activity and lipid peroxidation presumably depend on the various subunit combinations in their composition. All the plant cell systems that caused an uncoupling of oxidation and phosphorylation in plant mitochondria can participate in plant defence from oxidative damage during cold stress

The Daily Dynamics of Phenolic Compounds Content and Guaiacol-Peroksidase Activity in Leaves and Flowers of Alchemilla subcrenata and Veronica chamaedrys

The daily dynamics of peroxidase activity and the total content of phenolic compounds in leaves and inflorescences of Alchemilla subcrenata Buser and Veronica chamaedrys L. were studied. Significant changes in the content of phenolic compounds and activity peroksidase depending on the time of day was shown

Session 17 Ecophysiology

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Ogranichitel'nye mery ES v otnoshenii Rossii: pravovaja priroda i problema implementacii

The author proposes his take on the EU sanctions against Russia. He aims to understand the legal nature of the EU restrictions, the exact procedure of their implementation, revision, and repeal, as well as their judicial review. To this end, he proposes a system of sanction classification, analyses current EU legislation on the imposition and implementation of sanctions, as well as the case law on the sanction policy. The author also examines EU sanctions imposed on other countries and compares them to the Russian ones. He thus comes up with the following classification of sanctions against Russia: individual sanctions, those targeted at Crimea and Sevastopol, and anti-Russian economic sanctions. He concludes that the EU sanctions against Russia are inconsistent with the legal nature of restrictive measures, since they are a punishment rather than a policy tool. The author believes that in the current political conditions it may be difficult for the European Union to reach a unanimous agreement to repeal or prolong the sanctions. This article is inspired by the discussions that took place during the international conference “Russia and the EU: the Question of Trust” held in Luxembourg on November, 28—29 (2014)