Antimicrobial Activity of Milk Whey in Different Mammals.

Antimicrobial activity of milk whey in different mammals against Candida albicans yeast cells was studied by a spectrophotometric method. The activity increased in the order goat→horse→camel→cow→human→mouse. The level of whey activity in mice was higher by 3 and 10 times than in humans and goats, respectively. Similar changes were noted for activity of the whey fraction <100 kDa containing a complex of antimicrobial polypeptides, and there was a direct correlation between these two parameters (r=0.881; p<0.05). The total activity of whey had a high degree of correlation with the content of serum albumin (r=0.992); in mice, the level of serum albumin in the milk whey was close to that in blood serum. Interspecific differences between the activity of whey in mammals may be associated with qualitative and quantitative variability of the antimicrobial polypeptide composition, as well as their synergistic or antagonistic interaction with each other.

[Age dynamics of cell reaction in the preoptic hypothalamic nucleus during melatonin administration with a special reference to blockade and activation of the kisspeptinergic system].

Kisspeptin activates neurocytes and astrocytes of the preoptic hypothalamic nucleus of 1-, 3- and 24-month-old male rats. Kisspeptin antagonist (P-234) depresses the neurocytes, but not the astrocytes of the preoptic nucleus. Melatonin at a dose of 100 mkg/100 g b.w. inhibits the neurons of old male rats. During combined administration of melatonin and kisspeptin, as well as melatonin and P-234, the state of the kisspeptinergic system is crusial for the activity of the neurons in the preoptic nucleus of 1- and 3-month-old animals. However, in old rats melatonin significantly changes the neuron response of the preoptic nucleus to kisspeptin and its antagonist administration, while it's observed the neuron stimulation. Generally, the state of the kisspeptinergic system has a determining influence on the preoptic hypothalamic nucleus of the immature and young mature male rats. In old rats the cell functional state of the preoptic nucleus depends on the interaction of the kisspeptinergic system and melatonin level.

Modification of phytohormone response by a peptide encoded by ENOD40 of legumes and a nonlegume.

The gene ENOD40 is expressed during early stages of legume nodule development. A homolog was isolated from tobacco, which, as does ENOD40 from legumes, encodes an oligopeptide of about 10 amino acids. In tobacco protoplasts, these peptides change the response to auxin at concentrations as low as 10(-12) to 10(-16)M. The peptides encoded by ENOD40 appear to act as plant growth regulators.

[Pea (Pisum sativum) genes, participating in symbiosis with nitrogen-fixing bacteria. III. Study of the structure of the ENOD12 early nodulin gene for various types of peas using the polymerase chain reaction (PCR)]. / Geny gorokha (Pisum sativum), uchastvuiushchie v simbioze s azotfiksiruiushchimi bakteriami. II. Issledovanie struktury gena rannego nodulina ENOD12 dlia razlichnykh sortov gorokha s pomoshch'iu polimeraznoi tsepnoi reaktsii (PCR).

We have determined the length of early noduline gene ENOD12 in various varieties and lines of pea (Pisum sativum) using the polymerase chain reaction (PCR). It was demonstrated that promoter regions of ENOD12A and ENOD12B genes in line 2150 (Afghanistan) are longer than these in variety "Feltham first". The disparity is 14 bp. When studying these genes in 7 different lines and varieties of pea it was found that ENOD12A gene is more variable in size than the ENOD12B gene. We showed the possibility to analyze the heritage of ENOD12 gene's alleles by using the PCR method.

[Study of the immunotropic activity of aminoglycoside antibiotics]. / Izuchenie immunotropnoi aktivnosti antibiotikov iz gruppy aminoglikozidov.

The action of some aminoglycoside antibiotics on the immune system was studied on both intact mice and the animals with immune deficiency caused by administration of cyclophosphamide. The following tests were used: local hemolysis (the Herne test), lymphocyte transformation (LT), delayed hypersensitivity to sheep red blood cells and the local graft versus host reaction (GVHR). Amikacin was shown to have no significant action on the activity of lymphocytes in the intact mice and stimulated both cellular (LT and GVHR) and humoral (the Herne test) immunity in the animals with lowered immunological reactivity. Sisomicin had no significant action on the immune system of the animals. Gentamicin suppressed the immune response only in the intact mice. Kanamycin and streptomycin induced inhibition of humoral and cellular immunity in both the intact mice and animals with immune deficiency. On the basis of the results it was concluded that gentamicin, amikacin and sisomicin may be used in the treatment of diseases developing in the presence of immune deficiency whereas streptomycin and kanamycin should be recommended when inhibition of the immunity is needed.

Agricultural genomics and subterranean plant-plant communications.

Agricultural genomics has the potential to dramatically enrich the availability and quality of food supplies worldwide. However, because thousands of different plant species are grown for food, the application of genomics to crop improvement faces issues distinct from those in medical research. The challenge to agricultural plant scientists is to exploit the databases being generated for rice, maize, and Arabidopsis toward the genetic improvement of non-model crop species. The work in our lab illustrates one example of how genomic approaches can be applied to a non-model plant. Our overall goal is to understand how roots of different plants interact and use this information to improve the subterranean performance of crops in relation to weeds. The most obvious manifestation of root-root interactions is haustoria development. Haustoria are parasitic plant-specific organs that invade host plants and rob them of water and nutrients. Parasitic members of the Scrophulariaceae develop haustoria in vitro when exposed to molecules released by host roots. This is a useful phenotype for investigating plant-plant interactions because it is rapid, highly synchronous, and strictly dependent on exogenous haustoria-inducing factors (HIFs). Using a PCR-based subtractive hybridization, we cloned several hundred cDNAs representing transcripts one to two orders of magnitude more abundant in the roots of a parasitic plant after HIF exposure. Putative functions for about 90% of these transcripts could be assigned by searching the public databases. These have been arrayed on nylon filters and interrogated with a variety of probes from different parasitic and nonparasitic plants. Results from these experiments allowed us to identify likely candidate genes for the perception and processing of root signals by neighboring plants.

Transcriptional responses in the hemiparasitic plant Triphysaria versicolor to host plant signals.

Parasitic plants in the Scrophulariaceae use chemicals released by host plant roots to signal developmental processes critical for heterotrophy. Haustoria, parasitic plant structures that attach to and invade host roots, develop on roots of the hemiparasitic plant Triphysaria versicolor within a few hours of exposure to either maize (Zea mays) root exudate or purified haustoria-inducing factors. We prepared a normalized, subtractive cDNA library enriched for transcripts differentially abundant in T. versicolor root tips treated with the allelopathic quinone 2,6-dimethoxybenzoquinone (DMBQ). Northern analyses estimated that about 10% of the cDNAs represent transcripts strongly up-regulated in roots exposed to DMBQ. Northern and reverse northern analyses demonstrated that most DMBQ-responsive messages were similarly up-regulated in T. versicolor roots exposed to maize root exudates. From the cDNA sequences we assembled a unigene set of 137 distinct transcripts and assigned functions by homology comparisons. Many of the proteins encoded by the transcripts are predicted to function in quinone detoxification, whereas others are more likely associated with haustorium development. The identification of genes transcriptionally regulated by haustorium-inducing factors provides a framework for dissecting genetic pathways recruited by parasitic plants during the transition to heterotrophic growth.

Quinone oxidoreductase message levels are differentially regulated in parasitic and non-parasitic plants exposed to allelopathic quinones.

Allelopathic chemicals released by plants into the rhizosphere have effects on neighboring plants ranging from phytoxicity to inducing organogenesis. The allelopathic activity of naturally occurring quinones and phenols is primarily a function of reactive radicals generated during redox cycling between quinone and hydroquinone states. We isolated cDNAs encoding two distinct quinone oxidoreductases from roots of the parasitic plant Triphysaria treated with the allelopathic quinone 2,6-dimethoxybenzoquinone (DMBQ). TvQR1 is a member of the zeta-crystallin quinone oxidoreductase family that catalyzes one-electron quinone reductions, generating free radical semiquinones. TvQR2 belongs to a family of detoxifying quinone oxidoreductases that catalyze bivalent redox reactions which avoid the radical intermediate. TvQR1 and TvQR2 message levels are rapidly upregulated in Triphysaria roots as a primary response to treatment with various allelopathic quinones. Inhibition of quinone oxidoreductase enzymatic activity with dicumarol prior to quinone treatment resulted in increased transcript levels. While TvQR2 homologs were upregulated by DMBQ in roots of all plants examined, TvQR1 homologs were upregulated only in roots of parasitic plants. Phylogenetic trees constructed of TvQR1 and TvQR2 protein homologs in Archea, Eubacteria and Eukaryotes indicated that both gene families are ancient, yet the families have dissimilar evolutionary histories in angiosperms. We hypothesize that TvQR2-like proteins function to detoxify allelopathic quinones in the rhizosphere, while TvQR1 has specific functions associated with haustorium development in parasitic plants.

Comparison of soybean and pea ENOD40 cDNA clones representing genes expressed during both early and late stages of nodule development.

A pea cDNA clone representing the homologue of the soybean pGmENOD40-1 was isolated and characterized. At the nucleotide level both clones share 55% homology. Strikingly, the homology between the polypeptides derived from the pea and soybean ENOD40 cDNA sequences is only 14%. Despite this low homology Southern analyses revealed that the isolated pea cDNA clone represents the single pea ENOD40. In situ hybridizations showed that at early stages of nodule development and in mature nodules the expression pattern of pea ENOD40 is comparable to that of soybean ENOD40. Although ENOD40 show similar expression patterns in these two nodules, it is questionable whether the putative polypeptides have a similar function, since the homology is very low.

The pea early nodulin gene PsENOD7 maps in the region of linkage group I containing sym2 and leghaemoglobin.

The early nodulin gene, PsENOD7, is expressed in pea root nodules induced by Rhizobium leguminosarum bv. viciae, but not in other plant organs. In situ hybridization showed that this gene is transcribed during nodule maturation in the infected cells of the proximal part of the prefixation zone II. At the transition of zone II into interzone II-III, the level of PsENOD7 mRNA drops markedly. PsENOD7 has no significant homology to other genes. RFLP mapping studies have shown that PsENOD7 is located in linkage group I between the leghaemoglobin genes and sym2.