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Using C-banding and FISH methods, the karyotype of MC1611 induced mutant of bread wheat, which develop additional spikelets at a rachis node (trait "supernumerary spikelets") was characterized. It was determined that the mutant phenotype is not associated with aneuploidy and major chromosomal rearrangements. The results of genetic analysis showed that supernumerary spikelets of the line are caused by a mutation of the single bh-D. 1 gene, influenced by the genetic background. The mutation causes abnormalities of inflorescence morphogenesis associated with the development of ectopic spikelet meristems in place of floral meristems in the basal part of the spikelets, causing the appearance of additional spikes at a rachis node. The mutant phenotype suggests that the Bh-D gene determines the fate of the lateral meristem in ear, which develops as floral meristem and gives rise to floral organs in wild-type inflorescences. In the Bh-D. 1 mutant, the establishing identity is impaired. The characterized mutant can be used in further studies on molecular genetic basis of development of wheat inflorescence.

Dynamics of an antipodal complex formation in wheat (Triticum aestivum L.) has been observed in detail using a reconstruction of serial semifine sections. Three consecutive crucial stages have been identified in the development of the antipodal complex: (1) proliferation of initial cells, (2) growth and functional differentiation of antipodal cells, and (3) cell apoptosis. Specific features of the mitotic division of antipodal cells have been characterized. It has been shown that the structure of interphase nuclei and mitotic chromosomes of proliferating antipodal cells is similar to that of nucellar cells surrounding the embryo sac. According to the reconstruction of appropriately oriented serial sections, the division of antipodal cells is asynchronous. DNA content in differentiated antipodal cells has been determined by a cytophotometric analysis; in the case of a mature embryo sac, the ploidy of antipodal cells varied from 8 to 32C. Proliferation and DNA endoreduplication processes in the antipodal complex proceed at different time; the second process starts only after the termination of the first one. DNA endoreduplication is accompanied by total chromatin remodeling; as a result, giant chromosomes are formed in the nuclei of antipodal cells. The final stage of the antipodal complex development is programmed cell death or apoptosis. A model for the structural organization of an antipodal complex has been proposed based on the layer arrangement of cells. The secretory activity of antipodal cells directed towards the endosperm syncytium has been detected for the first time. The analysis of "truncated" ovules with an undeveloped endosperm has shown that developing endosperm can be a possible inductor, which stimulates the functional activity of antipodal cells and triggers their terminal differentiation. The obtained results evidence the functional role of antipodal cells in the development of the endosperm and embryo.

The effect of rye chromosomes on polyembryony was studied for reciprocal hybrid combinations between (Hordeum vulgare L.)-Triticum aestivum L. alloplasmic recombinant lines and five wheat T. aestivum L. (cultivar Saratovskaya 29)-rye Secale cereale L. (cultivar Onokhoiskaya) substitution lines: IR(1D), 2R(2D), 3R(3B), 5R(5A), and 6R(6A), and for direct hybrid combinations between the [H. marinum ssp. gussoneanum (H. geniculatum All.)]-T. aestivum alloplasmic recombinant line and the wheat-rye substitution lines 1R (1A), 1R (1D), and 3R(3B). Chromosomes 1R and 3R of rye cultivar Onokhoiskaya proved to affect the expression of polyembryony in the hybrid combinations that involved the alloplasmic recombinant lines of common wheat as maternal genotypes. Based on this finding, polyembryony was regarded as a phenotypic expression of nuclear-cytoplasmic interactions where an important role is played by rye chromosomes 1R and 3R and the H. vulgare cytoplasm. Consideration is given to the association between the effect of rye chromosomes 1R and 3R on polyembryony in the [(Hordeum)-T. aestivum x wheat-rye substitution lines] hybrid combinations and their stimulating effect on the development on angrogenic embryoids in isolated anther cultures of the wheat-rye substitution lines.

The parameters for delivery of expression cassettes to cells of wheat morphogenic callus induced from immature embryos were optimized. Three systems (gradation, delayed, and regeneration) for in vitro selection of transgenic wheat tissue using the bar gene, providing resistance to the herbicide phosphinothricin (PPT), were compared. The efficiency of gene delivery to the cells competent for plant regeneration was assessed by comparing the number of spots transiently expressing uidA gene (encoding beta-glucuronidase) per unit surface of the morphogenic calluses treated under various conditions. The selection systems in question were evaluated by comparing the transformation efficiency frequencies. The optimal parameters for wheat biolistic transformation using a particle inflow gun were determined, namely, the distance between the particle source and the target tissue (12 cm) and helium pressure during the shot (6 atm). The optimal time of callus tissue development on the medium inducing callus formation was determined (10-14 days). Comparison of the three selection variants demonstrated that the regeneration system was the most efficient for producing true transgenic plants of common wheat.

A method of isolation and purification of lipase (EC 3.1.1.3) from the germ of wheat (Triticum aestivum) is described. Electrophoretically homogeneous preparation of the enzyme (specific activity, 622.5 x x 10(-3) mumol/min per mg protein) was obtained after purification in 61 times. The molecular weight of the enzyme, determined by gel chromatography, was 143 +/- 2 kDa. The optimal conditions for the enzyme were 37 degrees and pH 8.0. Homogeneous preparation of the lipase exhibited high thermal stability: over 20% of original activity was retained after incubation of the preparation at high temperatures (60-90 degrees) for 1 h at pH 8.0.

The effects of rye chromosomes 1R and 5R on androgenesis in cultured anthers of wheat--rye substitution lines was studied as dependent on the cultivar origin of the rye chromosomes and on the wheat genome (A or D) subjected to substitution. Chromosome 1R stimulated embryogenesis in anther cultures, while chromosome 5R suppressed it regardless of whether the corresponding wheat chromosomes were substituted in the A or D genome. The effect of chromosome 1R on embryogenesis proved to depend on its cultivar origin. Along with rye chromosome 1R, wheat chromosome 1A was shown to substantially affect total seedling regeneration. Regeneration of green seedlings was dramatically affected both by rye chromosome 1R and by wheat chromosome 1D. The results supported the published data that individual androgenesis parameters (embryogenesis, total plant regeneration, green plant regeneration) are controlled by different genetic mechanisms.

The results of a complex estimation of hybrid lines isolated in F10 from a crossing octoploid triticale and winter hard wheat after a spontaneous hybridization of partially sterile plants with synthetic amphiploid H74/90-245 are presented. It is shown that neither contents of trypsin inhibitor nor resistance to fusarial rots conjugate with resistance to other diseases or to frost. Activity of trypsin inhibitor in grain endosperm allow a decision to be made concerning the presence of alien genetic material in the wheat genome. The donors of group resistance to diseases with a high protein content in a flour are selected.

The characteristic features of androgenesis in six wheat-rye substitution lines Triticum aestivum L. (cv. Saratovskaya 29)/Secale cereale L. (cv. Onokhoiskaya) and triticale (2n = 56) using anther culture at different concentrations of 2,4-D in the growth medium were studied. Under variable cultivation conditions, the significant effect of genotypic diversity on the variability of such androgenesis parameters as the frequency of productive anthers, the frequency of embryoid formation, and the frequency of total regenerated plantlets, was shown. It was demonstrated that chromosomes 1R, 3R, and 7R stimulated the formation of androgenous embryoids, while chromosome 5R produced an opposite effect. In triticale and substitution lines, the regeneration ability of androgenous embryoids induced by elevated 2,4-D concentrations was inhibited. Chromosome 1R of the Onokhoiskaya cultivar was suggested to contain genes suppressing regeneration of green plantlets, while chromosome 3R, conversely, stimulated their formation. Chromosomes 1R, 2R, 3R, and 7R of the Onokhoiskaya cultivar did not inhibit the spontaneous formation of androgenous hexaploids in the substitution lines.

The dynamics of peroxidase activity and antioxidant contents in wheat seeds were studied in the course of 24-hour swelling at 5 degrees C (group 1) and 23 degrees C (group 2). Both parameters were 1.5 times higher in seeds of the first group. In the same seeds, peroxidase activity in the endosperm and seed coat increased by factors of 1.5 and 1.8, respectively. Catalytic constants of wheat seed peroxidase were determined in the reactions of o-dianisidine and ascorbic acid peroxidation. In the pH range studied (pH 5-7), Km proved to change only slightly. In seedlings, an increase in the lipid peroxidation rate was accompanied by an increase in the content of antioxidants. Peroxidase activity increased as the content of antioxidants decreased, and vice versa. Thus, the reciprocal influence of peroxidase and low-molecular antioxidants during seed germination in wheat was revealed.

The surface of wheat androgenic embryoids and calli at different developmental stages was studied using SEM. The embryoids were already characterized by regular cell divisions at the early developmental stages, while the calli were represented by irregular cell conglomerates. This trend was preserved during further development of androgenic structures. SEM studies of the surface of so-called secondary embryoids confirmed these observations.

Data of the cytoembryological analysis of plants of super-dwarf wheat grown in laboratory experiment with elevated ethylene content in atmosphere were compared with results of space experiment and the ground control with ambient ethylene concentration. It was shown that crop barrenness in both the space and ground experiments was caused by exposure to increased ethylene throughout the whole ontogenesis which made pollen nonviable. The cytogenetic analysis revealed that male sterility of the wheat flowerlets in space flight evolved, as a rule, earlier and was deeper by character, i.e. pollen did not progress farther than the one-nucleus phase, whereas in the laboratory experiment with ethylene the pollen grains reached sometimes even the three-nucleus phase.

The role of nonsteady phenomena determined by a low velocity of ion movements in a weak external field is considered in relation to their possible nonlinear effects on processes occurring in boundary layers near the membrane, particularly, on the release of membrane-bound proteins and pH value. It is shown that a short-term treatment of wheat seeds with low-frequency magnetic field at the stage of esterase activation during seed swelling enhances the activation of esterases; the effect observed at final stages of activation depends on the time after the treatment with electromagnetic field. Treatment of seeds with electromagnetic field at this stage changed qualitatively the time course of the release of reaction products into the medium: the reaction rate increased initially and then decreased below the control level. At earlier stages of swelling in treated seeds and at all stages in control seeds, the time course of the product release was linear. The retardation of the release of the reaction products at terminal stages of esterase activation is presumably related to the release of proteins and their complexes under the action of electromagnetic field and the resulting restoration of the barrier properties of membranes. Treatment with electromagnetic field also caused a noticeable acceleration of proton flow form the medium, which was judged from pH changes in the bulk medium and in the vicinity of germ surface. The difference between the treated and control samples after 23-24 h of imbibition became statistically significant and was as high as 0.4 pH units. By taking into account the nonsteady phenomena occurring upon action of low-frequency electromagnetic field, it is possible to explain unusual dependences of biological effects on the amplitude of the electromagnetic field, including the atypical enhancement of these effects by the action of weak low-frequency fields.

The response of the antioxidant system of sprouts of wheat Triticum aestivum L. to preliminary irradiation of seeds with UV light was studied. The dependence of lipid peroxidation and the extent of antioxidant activity on the duration of irradiation was studied. It was shown that low doses of UV radiation (5-15 min) stimulate the antioxidant protection of green wheat sprouts grown for eight days. Increasing the irradiation time to 30-60 min leads to the inhibition of lipid peroxidation by the antioxidant system. A more prolonged irradiation of seeds with UV light (for 1-6 h) led to an increase in the level of lipid peroxidation in sprouts. However, 1-2-day-old sprouts from seeds irradiated for 5-6 h, adapted themselves to the influence due to the compensatory mechanisms. By the 8th day of germination of preliminarily irradiated seeds, the content of antioxidants and malone dialdehyde returned to the norm. The dynamics of activity of peroxidase in seeds irradiated with low doses of UV light for 30 min was studied. It was found that on the third day of seed germination, a decrease in peroxidase activity followed by its slight increase occurred. The maximum activity of the enzyme in the endosperm was observed on day 5-6, and in roots and green sprouts, on day 3-5 of germination. It was concluded that antioxidants and peroxidase are involved in the compensatory mechanisms of inhibition of free radicals formed upon UV irradiation of seeds.

The cytoembryologic analysis of wet and dry samples of super dwarf wheat cultivated in greenhouse SVET aboard the MIR station over the whole cycle of vegetation was made with the use of light microscopy. Characteristic features of wheat development in space flight are plentiful early tillering, and formation and rapid growth of side shoots. Elementary spikelets in the composite head were more numerous but the top spikelets were rudimentary and, therefore, the ripe head contained less of these spikelets as compared with the ground controls (9-13 and 14, respectively). The number of florets in a spike was also higher reaching 14-16 vs. 7-8 in the control. Typically, no more than 4 to 5 florets vs. 3 in the control were fully differentiated while the others died off earlier in development. The fact that there were no caryopses found in the flight crop is explained by absolute male sterility appearing at different stages of staminal development: before archesporium formation, on the stage of differentiated archesporium, during meiosis, on the stage of microspores or uninucleate "pollen". The female generative system developed mainly without abnormalities. An assumption was made that elevated ethylene concentrations in the MIR atmosphere at the time of the wheat experiment were the cause for abnormal development of the male generative system which led to barrenness of the super dwarf wheat crop.

The Project of scientific programs MIR/SHUTTLE and MIR/NASA was allowed for studying the productional, cytoembryological, morphological, biomechanical and other characteristics of superclub wheat on cultivation in the Svet greenhouse on-board orbital complex. This work was aimed at studying the duration of the complete cycle of ontogenesis of wheat and its individual stages, the peculiarities of forming the reproductive organs, processes, fertilization and formation of the seed production while cultivating in the Svet greenhouse under terrestrial conditions. Superclub wheat has been the object of experimentation. On cultivation of superclub wheat in the Svet greenhouse at designated conditions it was found that the cycle duration "from seed to seed" was 90-97 days. The number of granules in the wheat-ears studied was quite low and ranged from 15 to 30%. Performed studies with applying the light microscopy have indicated that in superclub wheat the embryological processes occur in compliance with those regularities which are described for the other forms of soft wheat.

Changes in the small cytoplasmic RNA (scRNA) composition have been examined in wheat embryos exposed to heat shock conditions. A novel scRNA of about 135 nucleotides in length termed as 5.3S RNA, has been detected for the first time. With a rise in temperature from 26 degrees C up to 37 degrees C, the amount of 5.3S RNA increases 5 to 6 times. It was found that 5.3S RNA is localized predominantly on ribosomes and also in the fraction of native 40S ribosomal subunits known to contain translation preinitiation complexes. Upon dissociation of 80S monoribosomes under high ionic strength conditions (0.5 M KCl), 5.3S RNA remains to be bound to the 40S subunit, thus indicating their strong and specific interaction. 5.3S RNA is neither a precursor of the 5S rRNA nor a discrete fragment of high molecular weight ribosomal RNA. It was supposed that 5.3S RNA is transcribed by RNA polymerase III and involved in protein synthesis regulation in plant cells under heat shock conditions at the level of translation initiation.

The method of impulse gradient of NMR spin-echo was applied for studying limited water diffusion in yeast cells and embryons of wheat caryopsis. Results are presented of measuring the amplitude of the echo signal depending on the intensity of the impulse gradient of the magnetic field reaching the values up to 1.7 kGs/cm. The method is suggested of determining on the basis of experimental data the distribution function parameters of the sizes of limiting cell compartments taking into account the permeability of their walls (membranes).

A wheat germ cell-free system was used for translation of kappa-chain IgG1 messenger RNA isolated from mouse plasmacytoma MOPC 21 cells polysomes. The system was optimised for a number of ingredients of the incubation mixture. Incorporation of labelled amino acids in polypeptides was shown as a function of K+, Mg2+, exogenous mRNA concentration and time, mRNA was purificated by two successive oligo (dT)-cellulose chromatographies and two successive sucrose gradient centrifugations or polyacrylamide gel electrophoresis. Different fractions of poly(A)-RNA stimulated protein synthesis 20--30-fold in a wheat germ cell-free system. Analysis of the translation product of 14 and 16S mRNA by SDS-polyacrylamide gel electrophoresis revealed polypeptide comigrating with the authentic L-chain IgG1 and specifically precipitating by an antiserum to mouse IgG and L-chain IgGl (MOPC 21). The 18 and 28S mRNA fractions directed the synthesis of polypeptides with molecular weight up to 50 000 dalton. Immunospecific translation product of the 18 and 28S mRNA contain both L- and H-chains.