Symbiotic and genetic diversity of Rhizobium galegae isolates collected from the Galega orientalis gene center in the Caucasus

This paper explores the relationship between the genetic diversity of rhizobia and the morphological diversity of their plant hosts. Rhizobium galegae strains were isolated from nodules of wild Galega orientalis and Galega officinalis in the Caucasus, the center of origin for G. orientalis. All 101 isolates were characterized by genomic amplified fragment length polymorphism fingerprinting and by PCR-restriction fragment length polymorphism (RFLP) of the rRNA intergenic spacer and of five parts of the symbiotic region adjacent to nod box sequences. By all criteria, the R. galegae bv. officinalis and R. galegae bv. orientalis strains form distinct clusters. The nod box regions are highly conserved among strains belonging to each of the two biovars but differ structurally to various degrees between the biovars. The findings suggest varying evolutionary pressures in different parts of the symbiotic genome of closely related R. galegae biovars. Sixteen R. galegae bv. orientalis strains harbored copies of the same insertion sequence element; all were isolated from a particular site and belonged to a limited range of chromosomal genotypes. In all analyses, the Caucasian R. galegae bv. orientalis strains were more diverse than R. galegae bv. officinalis strains, in accordance with the gene center theory

Destabilization of light NREM sleep by thalamic PLC beta 4 deletion impairs sleep-dependent memory consolidation

Sleep abnormality often accompanies the impairment of cognitive function. Both rapid eye movement (REM) and non-REM (NREM) sleep have associated with improved memory performance. However, the role of composition in NREM sleep, consisting of light and deep NREM, for memory formation is not fully understood. We investigated how the dynamics of NREM sleep states influence memory consolidation. Thalamocortical (TC) neuron-specific phospholipase C beta 4 (PLC beta 4) knockout (KO) increased the total duration of NREM sleep, consisting of destabilized light NREM and stabilized deep NREM. Surprisingly, the longer NREM sleep did not improve memory consolidation but rather impaired it in TC-specific PLC beta 4 KO mice. Memory function was positively correlated with the stability of light NREM and spindle activity occurring in maintained light NREM period. Our study suggests that a single molecule, PLC beta 4, in TC neurons is critical for tuning the NREM sleep states and thus affects sleep-dependent memory formation

The water treated with low-frequency low-pressure glow plasma enhances the phytoavailability of selenium and promotes the growth of selenium-treated cucumber plants

For its specific physical and physicochemical properties, the water treated with low-frequency low-pressure glow plasma (GPTW) affects the growth of plants and enhances the phytoavalibility of selenium (Se) ions from the nutrient solution. The basic biometric and physiological parameters of cucumber and the uptake of Se ions applied as selenate (Na2SeO4) from the nutrient solution prepared using GPTW or distilled water (DW) were compared. In the presence of Se, the fresh weight (f.w.) of shoots of plants growing in waterdifferentiated nutrient solutions did not differ, whilst their dry weight (d.w.) and leaf area (LA) were higher in plants grown in the GPTW- than in DW-containing medium. The use of GPTW for preparation of the nutrient solution was associated with a substantial improvement of Se ions phytoavailability, compared to the regular growth medium based on DW. Despite the higher Se bioaccumulation in the GPTW- than in DW-based medium, the phytotoxicity of this element was not enhanced. GPTW-induced Se accumulation was remarkable and hence recommended for further study to understand the detailed mechanism GPTW action