Effect of Salt Stress on the Expression and Promoter Methylation of the Genes Encoding the Mitochondrial and Cytosolic Forms of Aconitase and Fumarase in Maize

The influence of salt stress on gene expression, promoter methylation, and enzymatic activity of the mitochondrial and cytosolic forms of aconitase and fumarase has been investigated in maize (Zea mays L.) seedlings. The incubation of maize seedlings in 150-mM NaCl solution resulted in a several-fold increase of the mitochondrial activities of aconitase and fumarase that peaked at 6 h of NaCl treatment, while the cytosolic activity of aconitase and fumarase decreased. This corresponded to the decrease in promoter methylation of the genes Aco1 and Fum1 encoding the mitochondrial forms of these enzymes and the increase in promoter methylation of the genes Aco2 and Fum2 encoding the cytosolic forms. The pattern of expression of the genes encoding the mitochondrial forms of aconitase and fumarase corresponded to the profile of the increase of the stress marker gene ZmCOI6.1. It is concluded that the mitochondrial and cytosolic forms of aconitase and fumarase are regulated via the epigenetic mechanism of promoter methylation of their genes in the opposite ways in response to salt stress. The role of the mitochondrial isoforms of aconitase and fumarase in the elevation of respiration under salt stress is discussed.     

Keine Leibesvisitation unter Videobeobachtung

Ohne Zusammenfassung Dr. Alexander Dix, LL.M. Berliner Beauftragter für Datenschutz und Informationsfreiheit     

Uniaxial waves in randomly heterogeneous elastic media

Propagation of uniaxial sound waves in heterogeneous linear elastic one-dimensional media is considered. The scalar wave equation is transformed by the Liouville substitution and the Dyson integral equation is applied for a statistically homogeneous field of heterogeneities that results in an integral spatial representation for the mean wave field. The mean field is analysed in detail for the following three correlation functions: (i) an exponential one; (ii) a mean-square differentiable correlation function with a hidden periodicity; and (iii) a non-differentiable correlation function with a hidden periodicity. Despite the variety of the stochastic properties of the media, the equation for the mean field takes formally the same form for the three cases. For this reason, the general case of the random elastic medium with an arbitrary heterogeneity of small scale is considered and simple closed form expressions for the mean field and attenuation are derived. Applicability of the modelling of extended complex engineering structures by one-dimensional random media is discussed. The overall mechanical parameters of the primary structure and the secondary systems determine average rigidity, average mass density and average wave speed, while the secondary systems determine the attenuation. The latter is shown to depend upon the size and range of the secondary systems.     

Syntactic complexity of context-free grammars over word monoids

 The syntactic complexity of context-free grammars defined over word monoids is investigated. It is demonstrated that every recursively enumerable language can be defined by a ten-nonterminal context-free grammar over a word monoid generated by an alphabet and six words of length two. Open problems are formulated. Received October 10, 1994/February 23, 1995     

Growth features of ammonium hydrogen<Emphasis Type="Italic">d</Emphasis>-tartrate single crystals

Ammonium hydrogend-tartrate (d-AHT) single crystals were grown in silica gel. The growth features of these crystals with variation of parameters like specific gravity of the gel, gel pH, acid concentrations, concentration of the feed solution and gel age were studied in detail.     

Optimal design of roller beds

Examples are cited for analyses of optimal structural parameters of a roller bed in developing a structure of uniform strength with minimal metal consumption. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 1, pp. 6–7, January, 2006.     

Vortex Stability in a Trapped Bose Condensate

A vortex in a trapped Bose-Einstein condensate can experience at least two Types of instabilities. (1). Macroscopic hydrodynamic motion of the vortex core relative to the center of mass of the condensate requires some process to dissipate energy. (2). Microscopic small-amplitude normal modes can also induce an instability. In one specific example, the vortex core again moves relative to the overall center of mass, suggesting that there may be only a single physical mechanism.