Effect of Synthetic Auxin Analogs (2.4-D and α-NAA) on Growth and Biosynthetic Characteristics of Suspension Cell Culture of Tribulus terrestris L.

Russian Journal of Plant Physiology - Effect of synthetic analogs of auxins—2.4-dichlorophenoxyacetic (2.4-D) and α-naphthylacetic (α-NAA) acids—on growth characteristics and...     

ITS1–5.8S rDNA–ITS2 and trnL-trnF Sequences as Markers for the Study of Species Diversity of Altai Feather Grasses

Russian Journal of Genetics - The ITS1–5.8S rDNA–ITS2 sequence of the 35S rRNA genes of 16 species of feather grasses and 2 species of false needlegrasses of the flora of the Altai...     

Effect of Furostanol Glycosides from Dioscorea deltoidea on Redox State of Alfalfa Cells In Vitro

Russian Journal of Plant Physiology - The effect of exogenous furostanol glycosides (FG) on the activity of redox enzymes was investigated in suspension cell culture of alfalfa (Medicago sativa...     

Adaptogenic action of the complex of phenylpropanoids on Dioscorea deltoidea cell culture under abiotic stress

Biological activity of the extract from golden root (Rhodiola rosea L.) roots, containing the complex of phenylpropanoids (CPP), was studied on the cell culture of yam (Dioscorea deltoidea Wall) under normal conditions and abiotic stress. The high radical-binding capacity of CPP relative to anion- and hydroxyl-radicals was observed. Having a high level of antiradical protection, CPP at a high concentration(100 μM) exerted prooxidant effect, causing a decrease in D. deltoidea cell viability and a decrease in the activities of antioxidant enzymes: superoxide dismutase, guaiacol-dependent peroxidase, and catalase, with the exception of ascorbate peroxidase. At treatment with 100 μM CPP, oxidase (prooxidant) activity of peroxidase increased by three times. The low CPP concentration (2 μM) did not induce substantial changes in the activities of tested enzymes and also a substantial increase in the oxidase activity of peroxidase. Under conditions of oxidative stress induced by paraquat and high temperature, CPP manifested adaptogenic action, increasing cell viability; however, under hyperosmotic stress, it was not efficient. CPP was most efficient at a low concentration after cell pre-incubation with it for 5 days. In this case, the amount of primary and secondary POL products increased. Shortening pre-cultivation with CPP reduced its defensive effect.     

Proline and functioning of the antioxidant system in Thellungiella salsuginea plants and cultured cells subjected to oxidative stress

The effects of proline on the functioning of antioxidant enzymes — superoxide dismutase (SOD) and ascorbate peroxidase (APO) — in Thellungiella salsuginea plants and cultured cells under normal conditions of culturing and under the influence of hydrogen peroxide (500 μM) were studied. Proline addition (0.2, 2, or 5 mM) to the medium for suspension culture or nutrient medium for plant growing resulted in the increase in the content of intracellular proline in both cultured cells and intact plant leaves and also in the activation of proline dehydrogenase, i.e., the enzyme degrading proline. Under normal conditions, treatment with proline exerted prooxidant action on both cellular and organismal levels. This was manifested in MDA accumulation and changes in APO and SOD activities. The amino acid alanine, used as a control, did not exert similar strong effect as proline. Application of 500 μM H₂O₂ on plant leaves resulted in the development of oxidative stress, whereas hydrogen peroxide addition into the culture medium — to the death of 50% of suspension cells. When plants and cultured cells were treated with 2 mM proline and than with H₂O₂, the number of dead cells in suspension was 35%, the content of MDA was decreased, APO was activated, and SOD activity was decreased in both cell culture and plant leaves. Thus, an increase in the intracellular proline concentration changed the redox balance and induced functioning of APO and SOD at both normal conditions of plant growing and cell culturing and under stress.     

Formation of protodioscin and deltoside isomers in suspension cultures of Nepal yam (<Emphasis Type="Italic">Dioscorea deltoidea</Emphasis> Wall.) cells

Changes in the content of the furostanol glycosides protodioscin and deltoside, particularly that of the (25S)-isomers of the glycosides, during suspension cultivation of different lines of Nepal yam (Dioscorea deltoidea Wall.) cells of the strain IFR-DM-0.5 has been investigated. The composition of furostanol glycosides has been characterized, and the dynamics of the accumulation of individual glycosides during lengthy subcultivation of cells maintained in flasks or in a barbotage bioreactor has been analyzed. A positive correlation between the growth and accumulation of substances that belonged to the class of furostanol glycosides has been demonstrated for cultured dioscorea cells, whereas the content of some of the individual glycosides varied considerably between the lines of the strain, cultures maintained under different conditions, and even between cells in different phases of the growth cycle. The increased content of (25R)-forms of the glycosides (protodioscin and deltoside) was correlated with a decrease in the cellular growth rate, whereas an increase in culture growth intensity occurred concomitantly to an increase of the amount of (25S)-isomers. This may be indicative of the specific stimulatory effect of (25S)-glycosides, but not the (25R)-forms, on cell proliferation in vitro. Thus, the concentration of (25S)-forms may increase due to the autoselection of cells capable of intensive division during prolonged cultivation.     

Sensitivity of antioxidant status of plant cells to furostanol glycosides

The present paper reports that in vitro plant objects (test tube plants and cell cultures), when subjected to furostanol glycosides (FG), underwent nonspecific reactions related to antioxidant status—decrease in peroxidation of lipids (POL) and increase in guaiacol-dependent peroxidase activity. The level of superoxide increased as early as after 5 min from contact with yam (Dioscorea deltoidea Wall) cells with FG. In this case, changes in POL processes and in activities of peroxidase and aldehyde-disposing emzymes were also observed. Upon a short-term cell exposure to FG, the levels of the primary POL products (conjugated dienes) increased, and that of the secondary POL products decreased compared to the control. These events were preceded by a rise in SOD activity and in an antioxidant activity of peroxidase along with a concurrent decrease in its oxidase (prooxidant) activity. The elevated activities of aldehyde-disposing enzymes aldehyde dehydrogenase and aldehyde reductase favored the reduction in the content of the secondary products of POL. Upon a long contact of FG with cells, the effect of FG was seen only at the initial and final phases of the culture growth cycle. Namely, FG diminished the POL level at the exponential growth phase and at the end of the cell degradation phase but had no effect at the stationary phase and the onset of the degradation phase. Therefore, the treatment with FG retarded the cell culture degradation and made the fall in cell viability not so dramatic by the end of the growth cycle. Actually, by the end of the degradation phase, the viability diminished down to 40% in the control but remained at 70% in the FG-treated counterpart.     

Biosynthesis of mini-antibodies to human ferritin in plant and bacterial producers

A recombinant scFv antibody against human spleen ferritin was expressed as a barstar-fused protein in Escherichia coli and in Nicotiana tabacum plants and suspension cell cultures. As demonstrated by immunoblotting with antibarstar antibodies, direction of the recombinant protein to the endomembrane system of plant cells ensured its stability and solubility. Production of the recombinant protein did not differ between parental transgenic plants and their first-generation progeny. Fusion with barstar allowed not only immunochemical detection of the recombinant scFv antibody, but also their purification from the plant material by affinity chromatography with barnase-His6 immobilized on a metal-affinity carrier.     

Transformation of tobacco with a gene for the thermophilic acyl-lipid desaturase enhances the chilling tolerance of plants

The desC gene for the acyl-lipid Delta9-desaturase from the thermophilic cyanobacterium Synechococcus vulcanus was introduced into Nicotiana tabacum under control of the 35S promoter. Expression of the desaturase was confirmed by Western blotting. Lipid analysis revealed that lipid content and the extent of fatty acid unsaturation significantly increased in leaves of transgenic plants. Chilling tolerance of those plants also increased, as estimated by the electrolyte leakage from the tissues damaged by cold treatments. Seeds of plants that expressed the desC gene imbibed at low temperatures demonstrated higher chilling tolerance than those of the control plants. The results demonstrate that the cyanobacterial thermophilic acyl-lipid desaturase was efficiently expressed in tobacco at ambient temperatures, and its expression resulted in the enhanced chilling tolerance of the transgenic plants.     

Cold shock domain proteins in the extremophyte <Emphasis Type="Italic">Thellungiella salsuginea</Emphasis> (salt cress): Gene structure and differential response to cold

Four genes encoding cold shock domain (CSD) proteins have been identified in salt cress Thellungiella salsuginea (halophila), an extremophyte currently recognized as a promising model for studying stress tolerance]. The deduced proteins prove highly homologous to those of Arabidopsis thaliana (up to 95% identity) and are accordingly enumerated TsCSDP1-TsCSDP4; after the N-proximal conserved CSD, they have respectively 6, 2, 7, and 2 zinc finger motifs evenly spaced by Gly-rich stretches. Much lower similarity (∼45%) is observed in the regions upstream of TATA-box promoters of TsCSDP1 vs. AtCSP1, with numerous distinctions in the sets of identifiable cis-regulatory elements. Plasmid expression of TsCSDP1 (like AtCSP1/3) rescues a cold-sensitive csp-lacking mutant of Escherichia coli, confirming that the protein is functional. In leaves of salt cress plants under normal conditions, the mRNA levels for the four TsCSDPs relate as 10: 27: 1: 31. Chilling to 4°C markedly alters the gene expression; the 4-day dynamics are different for all four genes and quite dissimilar from those reported for their Arabidopsis homologous under comparable conditions. Thus, the much greater cold hardiness of Thellungiella vs. Arabidopsis cannot be explained by structural distinctions of its CSDPs, but rather may be due to expedient regulation of their expression at low temperature.