Fast growth responses of barley and durum wheat plants to NaCl- and PEG-treatment: resolving the relative contributions of water deficiency and ion toxicity

Effects of adding osmotically comparable concentrations of PEG and NaCl to nutrient solution were studied in 1-week-old durum wheat (Triticum durum Desf., salt-sensitive) and barley (Hordeum vulgare L., more salt tolerant). Both treatments arrested leaf extension immediately, followed by partial recovery within 40–60 min. Similarities and differences were observed between the responses of the two species and between the two treatments. Typically, PEG-treatment increased leaf extensibility of both barley and wheat as measured by changes in leaf extension rate monitored by an electromechanical sensor to which a stretching counter-weight was added. In barley, NaCl-treatment increased extensibility in a similar way to PEG, but in wheat, extensibility did not change within 40 min of NaCl-treatment. The contrasting fast responses of wheat plants to NaCl and PEG treatments suggests that, unlike barley, wheat leaf extension was sensitive not only to osmotic effects of salinity, but also to ion toxicity. Thus, separate PEG- and NaCl-treatments enabled us to distinguish between ionic and osmotic effects and to show, for the first time, that ionic effects of salinity on leaf extension can commence after only short-term exposure (<1 h) in the case of a salt-sensitive species such as durum wheat.     

Biochemical properties of <Emphasis Type="Italic">Bacillus intermedius</Emphasis> subtilisin-like proteinase secreted by a <Emphasis Type="Italic">Bacillus subtilis</Emphasis> recombinant strain in its stationary phase of growth

Biochemical properties of Bacillus intermedius subtilisin-like proteinase (AprBi) secreted by a B. subtilis recombinant strain in the early and late stationary phases of growth have been determined. Protein structure was analyzed and its stability estimated. It was noted that the enzyme corresponding to different phases of bacterial growth retains activity in the presence of reducing and oxidizing agents (C₂H₅OH and H₂O₂). Different effects of bivalent metal ions on activity of two proteinase fractions were found. Calcium ions more efficiently activate proteinase secreted in the late stationary phase. Unlike the first enzyme fraction, the second forms catalytically active dimers.     

Pantoea brenneri AS3 and Bacillus ginsengihumi M2.11 as Potential Biocontrol and Plant Growth-Promoting Agents

Microbiology - The mechanisms of biocontrol action of the strains Pantoea brenneri AS3 and Bacillus ginsengihumi M2.11 were investigated. The ability of the strains to release ammonium and cyanide...     

Association of variable <Emphasis Type="Italic">rs1801282</Emphasis> locus of <Emphasis Type="Italic">PPARG2</Emphasis> gene with diabetic nephropathy

The association of the variable rs1801282 locus of the PPARG2 gene (peroxisome proliferator-activated receptor gamma) with type 2 diabetes mellitus and its complications was analyzed in inhabitants of the Republic of Bashkortostan. The genotype frequencies of the variable rs1801282 locus of the PPARG2 gene did not significantly differ in groups of healthy persons and patients with type 2 diabetes in all three considered inheritance models (codominant, dominant, and recessive). At the same time, it was demonstrated that the risk of one of the diabetic complications, i.e., diabetic nephropathy, was associated with the variable rs1801282 locus of the PPARG2 gene. Diabetic nephropathy was more common in patients with the C/C genotype (62.7%) compared to the C/G and G/G genotypes (37.5%), P = 0.036. The G allele is protective in regard to diabetic nephropathy (OR = 0.36) in patients with type 2 diabetes mellitus.     

Isolation and physico-chemical properties of homogenous nuclease from Serratia marcescens

A simplified procedure for purification of nuclease from Serratia marcescens, including chromatography on DEAE- and phosphocellulose in a stationary regime has been developed. The method described results in a physically homogenous enzyme, which does not contain phosphatase, phosphodiesterase or proteinase admixtures. The molecular weight of the enzyme as determined by polyacrylamide gel electrophoresis is 33 000 +/- 10%. p-Chloromercurybenzoate (10(-2) M) completely inactivates the enzyme, while beta-mercaptoethanol (0,64 M) in the presence of 2 M urea causes only partial inactivation of the enzyme. Urea (4 or 7 M), when added to the reaction mixture, increases the enzyme activity 2,2-, 1,7- and 1,4-fold as compared to native, denaturated DNA and RNA, respectively.     

Localization of alkaline phosphatase in cells of Bacillus intermedius

Alkaline phosphatase, an enzyme secreted by Bacillus intermedius S3-19 cells to the medium, was also detected in the cell wall, membrane, and cytoplasm. The relative content of alkaline phosphatase in these cell compartments depended on the culture age and cultivation medium. The vegetative growth of B. intermedius on 0.3% lactate was characterized by increased activity of extracellular and membrane-bound phosphatases. The increase in lactate concentration to 3% did not affect the activity of membrane-bound phosphatase but led to a decrease in the activity of the extracellular enzyme. Na2HPO4 at a concentration of 0.01% diminished the activity of membrane-bound and extracellular phosphatases. CoCl2 at a concentration of 0.1 mM released membrane-bound phosphatase into the medium. By the onset of sporulation, phosphatase was predominantly localized in the medium and in the cell wall. As is evident from zymograms, the multiple molecular forms of phosphatase varied depending on its cellular localization and growth phase.     

Diversity in the swimming motility and flagellar regulon structure of uropathogenic Morganella morganii strains

International Microbiology - In current times, the opportunistic pathogen Morganella morganii is increasingly becoming a cause of urinary tract infections. The condition has been further...     

Isolation,Purification, and Identification of the Secretion Compound Pantoea brenneri AS3 with Fungicidal Activity

Applied Biochemistry and Microbiology - The pantoea brenneri AS3 strain stimulates plant growth and is active against pathogens, releasing secondary metabolites into the culture medium that inhibit...     

Evaluation of diagnostic efficiency of the recombinant protein modeling immunodominant epitope V3 of envelope gp120 for immunoenzyme detection for HIV-1 infection antibodies

The third hypervariable domain V3 of the human immunodeficiency virus type 1 gpl20 envelope glycoprotein contains neutralizing epitopes and plays an important role in the diagnosis of HIV infection . Neutralizing antibodies bind to conserved epitope with sequence GPG of V3 loop. The effect of sequence variation on the antigenic properties of the V3 epitope gp120 was studied using five synthetic peptides. The amino acid sequence of the peptide corresponding to the V3 region gp120 of HIV-1 subtype C showed the highest immunoreactivity. The DNA fragment encoding V3-C region gp120 was synthesized by polymerase chain reaction and cloned into pET41b vector. The recombinant plasmid was expressed in the E. coli cells, and recombinant protein was purified using glutathione-S sepharose affinity chromatography. The serological activity of the recombinant protein was tested using ELISA and compared to activity of similar synthetic peptide. The results of this study showed that most immunoreactive agent was the amino acid sequence of V3 region gp120 of HIV-1 subtype C. The recombinant antigen comprising this sequence was more antigenic than synthetic peptide with the same sequence. The evaluation of this antigen shows that this protein is a good candidate for the immunoassay development.