共查询到20条相似文献,搜索用时 0 毫秒
1.
Ya. S. Kolodyazhnaya S. E. Titov A. V. Kochetov M. L. Komarova A. V. Romanova V. S. Koval’ V. K. Shumny 《Russian Journal of Genetics》2006,42(2):212-214
We studied the stress resistance of genetically modified (GM) tobacco plants bearing an antisense suppressor of the gene for proline dehydrogenase. Such plants are characterized by elevated proline content. The progeny of the transgenic plants were shown to have elevated salt tolerance. 相似文献
2.
Kolodiazhnaia IaS Titov SE Kochetov AV Komarova ML Romanova AV Koval' VS Shumnyĭ VK 《Genetika》2006,42(2):278-281
We studied the stress resistance of genetically modified (GM) tobacco plants bearing an antisense suppressor of the gene for proline dehydrogenase. Such plants are characterized by elevated proline content. The progeny of the transgenic plants were shown to have elevated salt tolerance. 相似文献
3.
E. M. Moiseeva D. A. Agafonov V. A. Velikov I. V. Volokhina M. I. Chumakov 《Russian Journal of Plant Physiology》2012,59(3):419-422
A fragment of the first exon of the proline dehydrogenase gene of arabidopsis (Arabidopsis thaliana L.) in antisense orientation was transferred to maize (Zea mays L.) genome by agrobacterial transformation in planta to elevate the content of free proline in maize cells. The presence of genetic structure carrying an antisense sequence of
the fragment of the proline dehydrogenase gene (ASPG) from the genome of diploid maize seedlings was corroborated by PCR method.
T-DNA insertions comprising ASPG were found in the genomes of 30 plants (1.2% of 2409 examined seedlings) belonging to the
generation T0. A reliable 4.6-fold increase in proline content was registered in the leaves of transformed maize plants. 相似文献
4.
John W. Einset 《Plant Cell, Tissue and Organ Culture》1996,46(2):137-141
Ethylene production was measured during vegetative and reproductive development in normal tobacco plants and in transgenic tobacco plants carrying antisense genes for tomato ACC oxidase driven by the 35S CaMV promoter (Hamilton et al., 1990). When expressed in three independently derived transgenic plants, the antisense ethylene gene failed to affect ethylene production in young/mature leaves or in stems but it did inhibit ethylene production in roots by 37–58%. Ethylene production in developing flowers (i.e. from small unopened flower buds up until open flowers at anthesis) was not affected in transgenic plants but ethylene production in fruits was inhibited by 35%. The most dramatic effect on ethylene production in transgenic plants was seen immediately after wounding leaf tissue, in which case the antisense gene inhibited wound ethylene production by 72%. Thus, the antisense gene composed of a 35S CaMV promoter driving a heterologous ACC oxidase sequence had differential effects on ethylene production in tobacco plants. 相似文献
5.
Ya. S. Kolodyazhnaya S. E. Titov A. V. Kochetov E. A. Trifonova A. V. Romanova M. L. Komarova V. S. Koval V. K. Shumny 《Russian Journal of Genetics》2007,43(7):825-828
Analysis of resistance of genetically modified tobacco plants bearing antisense suppressor of proline dehydrogenase gene and characterized with higher content of proline to elevated concentrations of heavy metals was performed. It was demonstrated that progeny of transgenic plants have high resistance to lead, nickel and cadmium ions. 相似文献
6.
Kolodiazgnaia IaS Titov SE Kochetov AV Trifonova EA Romanova AV Komarova ML Koval' VS Shumnyĭ VK 《Genetika》2007,43(7):994-998
Analysis of resistance of genetically modified tobacco plants bearing antisense suppressor of proline dehydrogenase gene and characterized with higher content of proline to elevated concentrations of heavy metals was performed. It was demonstrated that progeny of transgenic plants have high resistance to lead, nickel and cadmium ions. 相似文献
7.
Nuclear-organelle interactions: nuclear antisense gene inhibits ribulose bisphosphate carboxylase enzyme levels in transformed tobacco plants 总被引:31,自引:0,他引:31
The biosynthesis of ribulose bisphosphate carboxylase (RUBISCO) provides a model system for studying the coordination of nuclear and organelle gene expression, since this abundantly transcribed and expressed chloroplast enzyme is composed of small (SS) and large subunits (LS) encoded by a nuclear multigene family and a single chloroplast gene, respectively. We have tested the possibility that SS mRNA or protein levels affect LS mRNA amounts or LS protein production and accumulation. We find that expression of antisense DNA sequences for the SS in transgenic tobacco plants drastically reduces the accumulation of SS mRNA and SS protein. These changes are accompanied by corresponding reductions of LS protein but not LS mRNA amounts; accumulation of the LS protein appears to be regulated by translational and posttranslational factors. We also find that the transgenic plants display striking variations in growth that are correlated with antisense gene dosage. 相似文献
8.
Nonspecific inhibition of proline dehydrogenase synthesis in Escherichia coli during osmotic stress 总被引:2,自引:0,他引:2
C E Deutch J M Hasler R M Houston M Sharma V J Stone 《Canadian journal of microbiology》1989,35(8):779-785
L-Proline, which is accumulated by Escherichia coli during growth in media of high osmolality, also induces the synthesis of the enzyme degrading it to glutamate. To determine if proline catabolism is inhibited during osmotic stress, proline utilization and the formation of proline dehydrogenase were examined in varying concentrations of NaCl and sucrose. Although the specific growth rate of E. coli with proline as the sole nitrogen source diminished as the solute osmolality increased, a comparable reduction in growth rate occurred with ammonium as the primary nitrogen source. Proline catabolism, as measured in whole cells by the conversion of [14C]proline to [14C]glutamate, was only slightly inhibited by solute osmolalities up to 1.0 osmol/kg; more than 50% of the initial activity was still found at 2.0 osmol/kg. By contrast, the specific activity of proline dehydrogenase in bacteria grown in the presence of added solutes decreased to less than 20% of the control level. This reduction was related to a lower rate of synthesis, but was independent of genes currently known to be involved in osmoregulation or proline metabolism. The specific activities of tryptophanase, beta-galactosidase, and histidinol dehydrogenase were also reduced under similar growth conditions. These results indicate that while proline catabolism is not directly inhibited by high solute concentrations, prolonged exposure to osmotic stress leads to its reduction as part of a more general metabolic response. 相似文献
9.
A ribozyme gene and an antisense gene are equally effective in conferring resistance to tobacco mosaic virus on transgenic tobacco 总被引:4,自引:0,他引:4
R. de Feyter M. Young K. Schroeder E. S. Dennis W. Gerlach 《Molecular & general genetics : MGG》1996,250(3):329-338
Ribozymes of the hammerhead class can be designed to cleave a target RNA in a sequence-specific manner and can potentially be used to specifically modulate gene activity. We have targeted the tobacco mosaic virus (TMV) genome with a ribozyme containing three catalytic hammerhead domains embedded within a 1 kb antisense RNA. The ribozyme was able to cleave TMV RNA at all three target sites in vitro at 25°C. Transgenic tobacco plants were generated which expressed the ribozyme or the corresponding antisense constructs directed at the TMV genome. Six of 38 independent transgenic plant lines expressing the ribozyme and 6 of 39 plant lines expressing the antisense gene showed some level of protection against TMV infection. Homozygous progeny of some lines were highly resistant to TMV; at least 50% of the plants remained asymptomatic even when challenged with high levels of TMV. These plants also displayed resistance to infection with TMV RNA or the related tomato mosaic virus (ToMV). In contrast, hemizygous plants of the same lines displayed only very weak resistance when inoculated with low amounts of TMV and no resistance against high inoculation levels. Resistance in homozygous plants was not overcome by a TMV strain which was altered at the three target sites to abolish ribozyme-mediated cleavage, suggesting that the ribozyme conferred resistance primarily by an antisense mechanism. 相似文献
10.
11.
Tobacco plants were genetically transformed with the Arabidopsis thaliana heterologous hmg1 gene encoding 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme involved in the metabolism of terpenoid compounds. The hmg1 gene was inserted under the control of the 35S RNA double promoter from the cauliflower mosaic virus (CaMV 35S) both in direct and reverse orientation relative to the promoter. DNA analysis by polymerase chain reaction (PCR) and Southern blotting confirmed the transgenic nature of the tobacco plants obtained. DNA-RNA hybridization revealed expression of the hmg1 gene in these tobacco plants. The plants transformed with the antisense copy of the hmg1 gene differed from the control plants in delayed development and in flower color and shape. 相似文献
12.
V E Sudovtsov T Iu Zharmukhamedova G F Garifullina 《Izvestiia Akademii nauk SSSR. Seriia biologicheskaia》1989,(5):769-772
A comparative study of sorbitol dehydrogenase activity in bovine, calf, and rat liver cell cytoplasm has been carried out. The level of activity of the enzyme is several times greater than that of marker enzymes (alcohol dehydrogenase, glucose-6-phosphate dehydrogenase). The data obtained suggest that the polyol (sorbitol) metabolism pathway of glucose functions actively in mammalian liver cells. 相似文献
13.
14.
Toxicity of free proline revealed in an arabidopsis T-DNA-tagged mutant deficient in proline dehydrogenase 总被引:5,自引:0,他引:5
The toxicity of proline (Pro) to plant growth has raised questions despite its protective functions in response to environmental stresses. To evaluate Pro toxicity, we isolated an Arabidopsis T-DNA-tagged mutant, pdh, that had a defect in Pro dehydrogenase (AtProDH), which catalyzes the first step of Pro catabolism. The pdh mutant showed hypersensitivity to exogenous application of < or =10 mM L-Pro, at which wild-type plants grew normally. A dose-dependent increase in internal free Pro accumulation was observed in pdh plants during external Pro supply. These results do not just prove the toxicity of Pro, but also suggest that AtProDH is the only enzyme acting as a functional ProDH in ARABIDOPSIS: To further analyze the targets of Pro toxicity, we compared the expression of thousands of genes by pdh plants with that by wild-type plants by cDNA microarray analysis. Most genes were unaffected. Here we demonstrate Pro toxicity by using the pdh mutant and discuss a cause-and-effect action between an excess of free Pro and growth inhibition in ARABIDOPSIS. 相似文献
15.
Tobacco callus ( Nicotina tabacum cv. Badischer Geudertheimer) took up sorbitol rapidly and without a lag period from media with up to 0.7 M of the polyol. Accumulation of proline was greatly enhanced under these conditions and was proportional to the absorbed sorbitol, while the viability of the callus cultures was quite low after a few hours of incubation. Under moderate conditions (0.1 M sorbitol) as well as under severe osmotic shock (0.7 M sorbitol), the cells adapted by adjusting the sorbitol/proline ratio to ca 3. NaCl (0.1 M ) had the same effect as sorbitol (0.7 M ) on the survival rate, but only slightly affected proline synthesis in the first hours of incubation. Addition of 107 or 10 5 M abscisic acid (ABA) did not increase the proline content, but 10 7 M ABA delayed the deleterious effect of NaCl and improved the state of the cells. No influence of abscisic acid during the incubation with sorbitol could be detected. Two different strategies for the adjustment of tobacco callus to salinity and sorbitol are suggested: Non-ionic stress is controlled by the accumulation of proline, whereas ABA could be involved in the adaptation to ionic stress. 相似文献
16.
17.
Complementation of the nuclear antisense rbcS-induced photosynthesis deficiency by introducing an rbcS gene into the tobacco plastid genome 总被引:1,自引:0,他引:1
The small subunit (SS) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a nuclear gene-encoded protein that is imported into chloroplasts where it assembles with the large subunit (LS) after removal of the transit peptide to form Rubisco. We have explored the possibility that the severe deficiency in photosynthesis exhibited in nuclear transgenic tobacco (line alpha5) expressing antisense rbcS coding DNA that results in low SS and Rubisco protein content [Rodermel et al. (1988) Cell 55: 673] could be complemented by introducing a copy of the rbcS gene into its plastid genome through chloroplast transformation. Two independent lines of transplastomic plants were generated, in which the tobacco rbcS coding sequence, either with or without the transit sequence, was site-specifically integrated into the plastid genome. We found that compared with the antisense plants, expression of the plastid rbcS gene in the transplastomic plants resulted in very high mRNA abundance but no increased accumulation of the SS and Rubisco protein or improvement in plant growth and photosynthesis. Therefore, there is a limitation in efficient translation of the rbcS mRNA in the plastid or an incorrect processing and modification of the plastid-synthesized SS protein that might cause its rapid degradation. 相似文献
18.
The multifunctional proline utilization A (PutA) flavoenzyme from Escherichia coli catalyzes the oxidation of proline to glutamate in two reaction steps using separate proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate (P5C) dehydrogenase domains. Here, the kinetic mechanism of PRODH in PutA is studied by stopped-flow kinetics to determine microscopic rate constants for the proline:ubiquinone oxidoreductase mechanism. Stopped-flow data for proline reduction of the flavin cofactor (reductive half-reaction) and oxidation of reduced flavin by CoQ(1) (oxidative half-reaction) were best-fit by a double exponential from which maximum observable rate constants and apparent equilibrium dissociation constants were determined. Flavin semiquinone was not observed in the reductive or oxidative reactions. Microscopic rate constants for steps in the reductive and oxidative half-reactions were obtained by globally fitting the stopped-flow data to a simulated mechanism that includes a chemical step followed by an isomerization event. A microscopic rate constant of 27.5 s(-1) was determined for proline reduction of the flavin cofactor followed by an isomerization step of 2.2 s(-1). The isomerization step is proposed to report on a previously identified flavin-dependent conformational change [Zhang, W. et al. (2007) Biochemistry 46, 483-491] that is important for PutA functional switching but is not kinetically relevant to the in vitro mechanism. Using CoQ(1), a soluble analogue of ubiquinone, a rate constant of 5.4 s(-1) was obtained for the oxidation of flavin, thus indicating that this oxidative step is rate-limiting for k(cat) during catalytic turnover. Steady-state kinetic constants calculated from the microscopic rate constants agree with the experimental k(cat) and k(cat)/K(m) parameters. 相似文献
19.
20.
Growth, water content, osmotic pressure and solute content were examined for normal potato (Solanum tuberosum L. cv. Desiree) and a derivative (line D9X8a), which was genetically transformed with TL-DNA from Agrobacterium rhizogenes. Plants were grown (i) in vitro, (ii) in a growth chamber and (iii) in the field. In vitro, the transformed potato plants produced more biomass than the untransformed plants, partly because they had a higher water content. Potassium concentration and osmotic pressure were lower in cell sap extracted from the transformed potato shoots. In some cases the difference was as much as 50%. These differences were less clear, absent or reversed in plants from a growth chamber or from the field. In the field, however, transformed potato senesced early. It is suggested that a cellular basis for these observations may be changes induced by Ri TL-DNA expression products in plant membrane properties.Abbreviations Ri
root inducing
- Ti
tumour inducing
- T-DNA
transferred DNA 相似文献