Cytology and Genetics最新文献

Abstract

Genetic variations in the human CYP2C9 and CYP2D6 genes may affect drug metabolism and lead to alterations in phenotypes. Genetic variations are associated with toxicity, adverse drug reactions, inefficient treatment. Various in silico tools were combined to investigate the deleterious effects of missense non-synonymous single nucleotide polymorphisms (nsSNPs) of the human CYP2C9 and CYP2D6. The structural and functional effects of the high-risk non-synonymous SNPs in the human CYP2C9 and CYP2D6 were predicted by numerous computational mutation analysis methods. Out of 24 pathogenic missense SNPs in the CYP2C9, 22 nsSNPs had a decreasing effect on protein stability and 13 SNPs were showed to be located at conserved positions. Out of 27 high-risk deleterious non-synonymous SNPs in the human CYP2D6, 21 SNPs decreased protein stability and 16 nsSNPs were predicted to be positioned at conserved regions. Our present study suggests that the identified functional SNPs may affect drug metabolism associated with CYP2C9 and CYP2D6 enzymes.

The review examines the main stages of cytokinin biosynthesis and metabolism with an emphasis on the important role of cytokinin oxidase/dehydrogenase (CKO/CKX) in cytokinin degradation. In this context, arguments are made for the crucial importance of this enzyme in maintaining a balanced level of cytokinins in plants. The role of CKX genes encoding cytokinin oxidase/dehydrogenase in determining plant resistance to abiotic stress factors and their yield was analyzed. The molecular genetic ways of regulating the activity of CKX genes are characterized. The results of research on the regulation of CKO/CKX activity in increasing the resistance to abiotic stress and crop yield are summarized and the biotechnological ways of realizing such opportunities are described. Prospects for finding substances that inhibit CKO/CKX activity to create preparations for agriculture are outlined separately. Prospective chemical inhibitors of CKO/CKX and their effects on cultivated plants are considered.

Clematis tomentella 2001 (Ranunculaceae) is a typical drought-tolerant sand-fixing plant in desert ecosystem in northwest China. To elucidate the phylogenetic status of C. tomentella and its related species, we determined the complete chloroplast (cp) genome and analyzed their interspecific relationships. The result showed that the cp genome of C. tomentella was 159 816 bp in length, including two inverted repeats of 31 045 bp, a large single copy region of 79 535 bp, and a small single copy region of 18 191 bp. 136 genes were annotated across the whole cp genome, including 92 protein-coding genes, 8 rRNA genes, and 36 tRNA genes, as well as the GC content accounted for 38%. Crucially, we found that the regions of psbE-petL, trnG_UCC-atpA, ndhF-rpl32, and rps8-infA were highly divergent, which could be marked as DNA barcodes for the identification of C. tomentella in Ranunculaceae. A maximum likelihood phylogenetic tree revealed that C. tomentella was closely related to C. fruticosa. Our results provide the references and implications for the phylogenetic study of Clematis in Ranunculaceae in the future.

Background: Worldwide, Pigeonpea (Cajanus cajan L.) is a protein source. SBP-box transcription factors are crucial for plant development and regulation of stress resistance. The SBP genes in Pigeonpea were examined utilizing genomic information. Methods: Using databases, PlantTFDB and NCBI, SBP-box family genes of Pigeonpea were identified and then characterized in silico using bioinformatics tools. Results: In this study, 5 major chromosomes out of 11 and an unplaced scaffold of the Pigeonpea were found to have 24 SBP genes. Significant differences in CcaSBPs protein length, molecular weight, GRAVY value (grand average of hydropathicity), and theoretical isoelectric point were observed. It was shown by Gene Structure Display Server (GSDS) that all CcaSBP genes contain one or more introns. CcaSBP proteins and SBP proteins from other species (A. thaliana and O. sativa) were analyzed phylogenetically and grouped into seven major groups (I–VII). Through this, an effort has been made to present unique information on CcaSBP genes to study Pigeonpea growth and stress mechanisms.

γ-aminobutyric acid (GABA) is considered a molecule that combines the properties of a stress metabolite and a signaling molecule. At the same time, the importance of its functional interaction with other signaling mediators, in particular, reactive oxygen species (ROS) and calcium ions, for the implementation of stress-protective action on plant cells remains poorly researched. The authors studied the effect of GABA on the resistance of wheat seedlings (Triticum aestivum L., cultivar Doskonala) to potentially lethal heat stress and the participation of ROS and calcium in the manifestation of the effects of GABA. Treatment of seedlings with GABA in concentrations of 0.5 and 1 mM caused a significant increase in their survival after damaging heating in a water thermostat (10 min at 45°C). Under the influence of GABA, there was a transient increase in the content of hydrogen peroxide in the roots of seedlings, followed by an increase in the activity of antioxidant enzymes: superoxide dismutase, catalase, and guaiacol peroxidase. The specified effects of GABA were eliminated by the preliminary application of the hydrogen peroxide scavenger dimethylthiourea (DMTU) to the root incubation medium and were significantly suppressed in the presence of the NADPH oxidase inhibitor imidazole. At the same time, the treatment of seedlings with the chelator of extracellular calcium EGTA only partially eliminated the increase in the content of hydrogen peroxide and hardly affected the increase in the activity of antioxidant enzymes in the roots under the influence of GABA. Treatment with neomycin, an inhibitor of calcium uptake from intracellular compartments, caused a partial reduction in the effect of GABA on indicators of the state of the pro-/antioxidant system in wheat roots but did not eliminate these effects. Under the influence of GABA, damage to root cell membranes caused by heat stress was significantly reduced, which was manifested in a decrease in the release of UV-B-absorbing compounds from the cells and a decrease in the content of lipid peroxide oxidation products. At the same time, the stress-protective effect of GABA was eliminated by DMTU treatment and changed in the presence of calcium antagonists. A conclusion was made about the important role of ROS generated with the participation of NADPH oxidase in the implementation of the protective effect of GABA on wheat seedlings under conditions of heat stress and the partial dependence of its protective effects on calcium homeostasis.

For the first time, the effect of 5- and 10-day soil flooding on the ultrastructure of the leaf mesophyll cells of the psammophyte desert madwort (Alyssum desertorum L.) was investigated. The seeds for the experiments were collected from plants of dry sandy areas of the gully slopes of the ravine forest in the steppe zone of the Dnipropetrovsk oblast. It is shown that a characteristic feature of the leaf photosynthetic cells of this species is the presence of single and large, up to 6 pm, peroxisomes, which are in close contact with chloroplasts and mitochondria, playing a key role in photorespiration. The general organization of palisade parenchyma cells on days 5 and 10 of soil flooding is similar to that in the control. A slight decrease in the size of peroxisomes on day 5 of flooding and its increase on day 10 and more often formation of multivesicular structures (assembly of endomembranes) in the vacuole, which is considered as an autophagy enhancement of the cytoplasm under hypoxia, were noted. Differences in the ultrastructure of chloroplasts under the influence of soil flooding consisted in a significant, almost twofold increase in transient starch, the size and number of plastoglobules, especially on day 10, and swelling of granal and stroma thylakoids on day 10. Changes in the ultrastructure of desert madwort chloroplasts under the influence of soil flooding coincide with those of mesophytes studied in this respect. The obtained data on the chloroplast ultrastructure of desert madwort psammophyte prove the functioning of the photosynthetic apparatus in conditions of short-term soil flooding, which contributes to the survival of seedlings. The subsequent yellowing of leaves and death of plants indicates, as is assumed, the lack of systemic adaptation, primarily metabolic, that is, the transition to anaerobic metabolism, in this species to long-term hypoxia.

The pea is an important cool-season pulse crop cultivated for animal and human consumption. However, the presence of “flatulence-causing factors” hinders its consumption and acceptance worldwide. The raffinose family oligosaccharides (RFOs) have been identified as the principal “flatulence causing factors”. Hence, reducing RFO level is the major goal to promote pea consumption and acceptance worldwide. However, very little is known about the genes involved in RFO metabolism at the genome-wide scale in pea. In the present study, genes for five key enzymes (galactinol synthase, raffinose synthase, stachyose synthase, alpha-galactosidase_Acid/Alkaline and beta-fructofuranosidase) involved in RFO metabolism pathway were identified at the genome-wide scale in pea. A total of two galactinol synthase, two raffinose synthase, one stachyose synthase, six alpha-galactosidase_Alkaline and three alpha-galactosidase_Acid and ten beta-fructofuranosidase genes were identified in the pea genome. Phylogenetic relationships analysis, exon/intron structure as well as conserved domain within each enzyme family and their chromosomal location were also determined to establish their relationship with the known proteins. In silico anlaysis showed that pea RFO genes contain 26 microsatellite loci. Taken together, this study provides useful candidate genes for improving the nutritional quality of pea through genetic engineering approaches as well as microsatellite loci for the development of SSR markers for the introgression of low RFO trait through marker assisted selection.

Peculiarities of the genetic structure of the population of Holstein cattle bred in Ukraine were studied by beta-casein and tumor necrosis factor alpha loci. Using the methods of allele-specific PCR (AS-PCR) and PCR with restriction fragment length polymorphism (PCR-RFLP) analysis, polymorphism of the beta-casein gene (CSN2) by allelic variants A¹ and A² and of the tumor necrosis factor-alpha (TNF-α) by SacI-polymorphism in the promoter region of the gene (–824 A>G marker mutation) and RsaI-polymorphism in the fourth exon were analyzed. It was proven that both loci are polymorphic in the studied cattle population. For each of the polymorphic loci, the main genetic and population parameters of the Holstein cow population were established. For the CSN2 locus, a significant predominance of the frequency of the A² allele over A¹ was established (0.78 vs. 0.22). For the SacI- and RsaI-polymorphisms of TNF-α, maximal (1.980 and 1.988) values of the locus polymorphism level (the number of effective alleles) were detected. For both mutations in the TNF-α gene, actual parity in the frequency values of the corresponding alleles was established (0.55 and 0.45 for the SacI-polymorphism; 0.54 and 0.46 for the RsaI-polymorphism). For the RsaI-polymorphism in the TNF-α fourth exon, a deviation from the state of genetic equilibrium according to Hardy–Weinberg was recorded in the studied population of animals, and a significant excess of heterozygous individuals was detected (25%). Based on the results of the analysis of milk productivity parameters of individuals with different CSN2 locus genotypes, it was established that individuals with the A²A² genotype are characterized by higher values of standard milk production as compared with individuals with the A¹A¹ genotype (p = 0.042). For the SacI- and RsaI-polymorphism of the TNF-α gene, there were no significant differences in the parameters of standard milk productivity for two lactations between individuals with different genotypes.

To study the effect of brassinosteroids and salinity stress on the fatty acid metabolism in the seeds of oil plants, the authors analyzed the turnover of fatty acids in the seeds of Crambe tatarica under the mentioned conditions. The results of gas-liquid chromatography and mass-spectrometry demonstrated the decrease in the level of palmitic and linoleic fatty acids along with the increase in the level of oleic, eicosenoic, and docosenoic fatty acids in C. tatarica seeds in response to 28-homobrassinolide under salinity stress on some stages of seed germination. These regularities allowed for the assumption that 28-homobrassinolide promotes the stabilization of fatty acid composition of C. tatarica seeds, disrupted under salinity stress. This may indicate the possibility of modulating the activity or expression of desaturase genes and the enzymes of fatty acid oxidation in the anwer on brassinosteroids.