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1.
A. V. Kochetov S. E. Titov Ya. S. Kolodyazhnaya M. L. Komarova V. S. Koval N. N. Makarova Yu. Yu. Il'yinskyi E. A. Trifonova V. K. Shumny 《Russian Journal of Genetics》2004,40(2):216-218
The antisense suppressor was constructed for proline dehydrogenase gene (PDH; a fragment of PDH from Arabidopsis in antisense orientation and under the control of 35S promoter of cauliflower mosaic virus, CMV). In Nicotiana tabacum SR1 tobacco transformants bearing antisense suppressor for PDH, the proline content and the cytoplasm osmotic pressure were increased. The proline content in these transformants varied, whereas cytoplasm osmotic pressure was stable, which seems to reflect complicated relationships between these characteristics of the plant cell. 相似文献
2.
S. S. Ibragimova Ya. S. Kolodyazhnaya S. V. Gerasimova A. V. Kochetov 《Russian Journal of Plant Physiology》2012,59(1):88-96
The role of gene of proline dehydrogenase (PDH) in the maintenance of stress tolerance was investigated using the model transgenic
plants of tobacco (Nicotiana tabacum L.) carrying an antisense suppressor of PDH gene (a fragment of Arabidopsis PDH gene under the control of cauliflower mosaic virus 35S promoter in antisense orientation) and notable for a low activity
of PDH and elevated content of proline. The progeny of transgenic plants belonging to the 5th generation (T5) with partially suppressed PDH activity was more resistant to various types of stress as compared with the control plants of tobacco, cv. Petit Havana SR-1
(SR1). The seedlings of transgenic lines cultured in Petri dishes on agar media supplemented with stress agents were resistant
to high NaCl concentrations (200–300 mM) and water deficit simulated by an increased agar content in the medium (14 g/l) as
compared to the control seedlings of cv. SR1. Juvenile plants of transgenic lines grown in pots filled with a mixture of vermiculite
and perlite also manifested the higher resistance to water deficit and low temperatures (2°C and −2°C) than the control plants.
Thus, the partial PDH suppression correlated with an increase in nonspecific resistance to different types of abiotic stress: salinity, water deficit,
and low temperatures. Such transgenic lines of tobacco are promising genetic models for thorough investigation of molecular
mechanisms of stress resistance in plants. 相似文献
3.
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
4.
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
5.
Summary The effect of water stress on growth (fresh weight, dry weight), water relations (water saturation deficit, water potential, osmotic pressure), and proline metabolism in Phaseolus vulgaris were studied.Experimentally, water deficit was produced by reduced watering of the bean plants. This resulted in a decrease in water potential and leaf fresh and dry weight. Increases in the water saturation deficit and the osmotic pressure of the sap were, however, recorded. Water stress was also induced by treatment of the plants with polyethylene glycol, but its effects on the above mentioned parameters were different. In addition, necrosis of the foliage was observed. According to the present results, polyethylene glycol seems to be suitable only for the induction of short-termed water stress conditions.The effects of water stress on growth and on water relations of the plants were accompanied by a marked increase in the free amino acid content, especially that of the free proline content of the plants. The activities of the proline dehydrogenase and glutamate dehydrogenase were stimulated under water stress conditions, indicating that proline accumulation in water stressed plants is not attributed to an inhibited proline breakdown. The accumulated proline was metabolized rapidly once the water deficit of the plant was relieved by watering. The ability of the plant to accumulate proline might be of ecological importance for the plant and might be an adaption mechanism of the plant to overcome short periods of drought.Abbreviations -Kg
-ketoglutarate
- GDH
glutamate dehydrogenase
- PDH
proline dehydrogenase
- P5C
-pyrroline-5-carboxylic acid
- PEG
polyethylene glycol
- WSD
water saturation deficit 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.
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
8.
We reported previously that, when exposed to high osmotic pressure, Lactobacillus acidophilus IFO 3532 cells accumulated N,N,N-trimethylglycine (glycine betaine), which serves as a compatible intracellular solute. When grown in medium with high osmotic pressure, these cells also accumulated one amino acid, proline. The uptake of [3H]proline by resting, glucose-energized cells was stimulated by increasing the osmotic pressure of the assay medium with 0.5 to 1.0 M KCl, 1.0 M NaCl, or 0.5 M sucrose. The accumulated [3H]proline was not metabolized further. In contrast, there was no osmotic stimulation of [3H]leucine uptake. The uptake of proline was activated rather than induced by exposure of the cells to high osmotic pressure. Only one proline transport system could be discerned from kinetics plots. The affinity of the carrier for proline remained constant over a range of osmotic pressures from 650 to 1,910 mosM (Kt, 7.8 to 15.5 mM). The Vmax, however, increased from 15 nmol/min/mg of dry weight in 0.5 M sucrose to 27 and 40 nmol/min/mg of dry weight in 0.5 M KCl and in 1.0 M KCl or NaCl, respectively. The efflux of proline from preloaded cells occurred rapidly when the osmotic pressure of the suspending buffer was lowered. 相似文献
9.
Osmotically regulated transport of proline by Lactobacillus acidophilus IFO 3532. 总被引:2,自引:1,他引:1
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We reported previously that, when exposed to high osmotic pressure, Lactobacillus acidophilus IFO 3532 cells accumulated N,N,N-trimethylglycine (glycine betaine), which serves as a compatible intracellular solute. When grown in medium with high osmotic pressure, these cells also accumulated one amino acid, proline. The uptake of [3H]proline by resting, glucose-energized cells was stimulated by increasing the osmotic pressure of the assay medium with 0.5 to 1.0 M KCl, 1.0 M NaCl, or 0.5 M sucrose. The accumulated [3H]proline was not metabolized further. In contrast, there was no osmotic stimulation of [3H]leucine uptake. The uptake of proline was activated rather than induced by exposure of the cells to high osmotic pressure. Only one proline transport system could be discerned from kinetics plots. The affinity of the carrier for proline remained constant over a range of osmotic pressures from 650 to 1,910 mosM (Kt, 7.8 to 15.5 mM). The Vmax, however, increased from 15 nmol/min/mg of dry weight in 0.5 M sucrose to 27 and 40 nmol/min/mg of dry weight in 0.5 M KCl and in 1.0 M KCl or NaCl, respectively. The efflux of proline from preloaded cells occurred rapidly when the osmotic pressure of the suspending buffer was lowered. 相似文献
10.
Genetic manipulation of proline levels affects antioxidants in soybean subjected to simultaneous drought and heat stresses 总被引:7,自引:0,他引:7
Gábor Kocsy Robert Laurie Gabriella Szalai Virág Szilágyi Lívia Simon-Sarkadi Gábor Galiba Jacoba A. de Ronde 《Physiologia plantarum》2005,124(2):227-235
It was assumed that the genetic manipulation of the proline (Pro) level would also affect the (homo)glutathione content as both compounds have a common precursor, glutamate. To test this hypothesis, the levels of Pro, reduced and oxidized (homo)glutathione [(h)GSH and (h)GSSG] and other antioxidants were compared under simultaneous drought and heat stress conditions and in a control treatment in a time course experiment on wild-type soybean ( Glycine max cv. Ibis) and on transgenic plants containing the cDNA coding for l -Δ1 -pyrroline-5-carboxylate reductase (EC 1.5.1.2), the last enzyme involved in Pro synthesis, in the sense and antisense directions. At the end of the recovery period, the highest H2 O2 and lipid hydroperoxide concentrations were observed in the antisense transformants, which exhibited the greatest injury, while the lowest H2 O2 content was detected in the sense transformants, which exhibited the lowest injury percentage. During stress treatment, the highest Pro and ascorbate (AA) levels were detected in the sense transformants, while the highest GSH and hGSH contents, AA/dehydroascorbate (DHA) and (h)GSH/(h)GSSG ratios and ascorbate peroxidase (APX) activity were found in the antisense transformants. The greatest APX (EC 1.11.1.11) activity was observed in the first part of the stress treatment in the antisense transformants, and the greatest glutathione reductase (EC 1.6.4.2) activity was observed in the second part of the treatment in the same genotype. The present experiments indicate that the manipulation of Pro synthesis affects not only the (h)GSH concentrations, but also the levels of other antioxidants. 相似文献
11.
Factors reducing and promoting the effectiveness of proline as an osmoprotectant in Escherichia coli K12 总被引:6,自引:0,他引:6
Proline accumulation in Escherichia coli is mediated by three proline porters. Proline catabolism is effected by proline porter I (PPI) and proline/delta 1-pyrroline carboxylate dehydrogenase. Proline did not accumulate cytoplasmically when E. coli was subjected to osmotic stress in minimal salts medium. Although PPI is induced when proline is provided as carbon or nitrogen source, its activity decreased following growth of the bacteria in minimal salts medium of high osmotic strength. Proline dehydrogenase was induced by proline in low or high osmotic strength media. Proline porter II (PPII) was both activated and induced in osmotically stressed bacteria, though the dependencies of the two responses on medium osmolarity differed. Osmotic downshift during the transport measurement decreased the uptake of proline, serine and glutamine by bacteria cultured in media of high osmotic strength. Thus, while osmotic upshift caused specific activation of PPII, osmotic downshift caused a non-specific reduction in amino acid uptake. Glycine betaine inhibited the uptake of [14C]proline via PPII and PPIII but not via PPI. The dependence of that inhibition on glycine betaine concentration was similar when PPII was uninduced, induced or activated by osmotic stress, or induced by amino acid limited growth. Thus PPII and PPIII, not PPI, contribute to the mechanism of osmoprotection by proline and glycine betaine. The tendency for exogenous proline to accumulate in the cytoplasm of bacteria exposed to osmotic stress would, however, be countered by increased proline catabolism. 相似文献
12.
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
13.
H. -M. Ku C. -W. Tan Y. -S. Su C. -Y. Chiu C. -T. Chen F. -J. Jan 《Biologia Plantarum》2012,56(2):337-343
Fluctuation in proline content is a widespread phenomenon among plants in response to heavy metal stress. To distinguish between
the participation of water deficit and copper on changes in proline metabolism, potted plants and floating leaf discs of tobacco
were subjected to CuSO4 treatments. The application of copper increased the proline content in the leaves concomitantly with decreased leaf relative
water content and increased abscisic acid (ABA) content in the potted plant. Excess copper increased the expression of two
proline synthesis genes, pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT) and suppressed proline
catabolism gene, proline dehydrogenase (PDH). However, in the experiment with tobacco leaf discs floating on CuSO4 solutions, the excess copper decreased proline content and suppressed the expression of the P5CS, OAT and PDH genes. Therefore,
proline accumulation in the potted tobacco plants treated with excess Cu treatment might not be the consequence of the increased
copper content in tobacco leaves but rather by the accompanied decrease in water content and/or increased ABA content. 相似文献
14.
Cold acclimation of wheat (Triticum aestivum): Properties of enzymes involved in proline metabolism 总被引:3,自引:0,他引:3
Two cultivars of wheat ( Triticum aestivum L.), a winter wheat, Kharkov, and a spring wheat, Glenlea, were acclimated under controlled conditions at 2 temperatures, 5°C and 25°C with a 12-h photoperiod. Water content, protein and proline concentrations were determined. Enzymatic properties (activity and apparent energy of activation) were investigated for enzymatic systems involved in 2 pathways of proline metabolism, the glutamic acid and ornithine pathways. Four enzymes were studied, proline dehydrogenase (PDH, EC 1.5.1.2), glutamate dehydrogenase (GDH, EC 1.4.1.2-4), glutamine synthetase (GS, EC 6.3.1.2) and ornithine transaminase (OT, EC 2.6.1.13). Cold acclimation led to an accumulation of proline, a decrease in water content and an increase in soluble protein, especially in winter wheat. For both cultivars, cold acclimation modulated enzyme properties of PDH and GDH. Increased activities of GS and OT were observed as a result of cold acclimation in both cultivars, with the greatest increase in Kharkov. The apparent energy of activation of these 2 enzymes decreased, particularly for Kharkov, which accumulated proline in cold conditions. 相似文献
15.
NaCl effects on proline metabolism in rice (Oryza sativa) seedlings 总被引:10,自引:0,他引:10
Salt-stress effects on osmotic adjustment, ion and proline concentrations as well as proline metabolizing enzyme activities were studied in two rice ( Oryza sativa L.) cultivars differing in salinity resistance: I Kong Pao (IKP; salt-sensitive) and Nona Bokra (salt-resistant). The salt-sensitive cultivar exposed to 50 and 100 m M NaCl in nutritive solution for 3 and 10 days accumulated higher levels of sodium and proline than the salt-resistant cultivar and displayed lower levels of osmotic adjustment. Proline accumulation was not related to proteolysis and could not be explained by stress-induced modifications in Δ1 -pyrroline-5-carboxylate reductase (P5CR; EC 1.5.1.2) or proline dehydrogenase (PDH; EC 1.5.1.2) activities recorded in vitro. The extracted ornithine Δ -aminotransferase (OAT; EC 2.6.1.13) activity was increased by salt stress in the salt-sensitive cultivar only. In both genotypes, salt stress induced an increase in the aminating activity of root glutamate dehydrogenase (GDH; EC 1.4.1.2) while deaminating activity was reduced in the leaves of the salt-sensitive cultivar. The total extracted glutamine synthetase activity (GS; EC 6.3.1.2) was reduced in response to salinity but NaCl had contrasting effects on GS1 and GS2 isoforms in salt-sensitive IKP. Salinity increased the activity of ferredoxin-dependent glutamate synthase (Fd-GOGAT; EC 1.4.7.1) extracted from leaves of both genotypes and increased the activity of NADH-dependent glutamate synthase (NADH-GOGAT; EC 1.4.1.14) in the salt-sensitive cultivar. It is suggested that proline accumulation is a symptom of salt-stress injury in rice and that its accumulation in salt-sensitive plants results from an increase in OAT activity and an increase in the endogenous pool of its precursor glutamate. The physiological significance of the recorded changes are analyzed in relation to the functions of these enzymes in plant metabolism. 相似文献
16.
The rationale behind the study was to enhance azetedine-2-carboxylate (A2C)-linked stress in the germinating seeds to which it responds by increased proline synthesis to overcome inhibition of proline dehydrogenase (PDH). A2C is a competitive inhibitor of proline that inhibits its transport from cytosol to the mitochondria for further metabolic recycling by binding on to the active sites of PDH. The enhanced synthesis of proline would increase the ratio of the cofactors NADP/NADPH2. The increase in the cofactors would result in the over-expression of the phenypropanoid pathway required for the phenolic acids and L-DOPA synthesis via pentose phosphate pathway through the activity of glucose-6-phosphate dehydrogenase (G6PDH). Fava bean were chosen since it has high phenolic and L-DOPA levels and could be an important part of the diet especially for patients suffering from Parkinson's Disease. The objectives were investigated by assaying for total phenolic content, the corresponding antioxidant activity by β-carotene oxidation method, proline levels and enzymes such as G6PDH and guaiacol peroxidase (GPX) using spectrophotometric methods. L-DOPA was quantified using HPLC. The fava bean seeds were primed with water, 200 μM A2C, 0.25 mM proline and a combination of A2C and proline treatments. After the priming stage, seeds were dark germinated and grown for a period of 8 days, for biochemical analysis. L-DOPA levels did not change in comparison to the control treatments while total phenolic content, proline and G6PDH were all enhanced by the treatments. During the early stages of germination the phenolic acids were antioxidant in nature, which later was reduced as they become polymerized to lignins and lignans via the GPX activity. Total phenolic synthesis was both coupled and uncoupled to PLPPP depending on the treatments. The three treatments over-expressed PLPPP since large difference between control and the treatments were observed for all parameters, except L-DOPA content. 相似文献
17.
18.
Asish Kumar Parida Vipin S. Dagaonkar Manoj S. Phalak Laxman P. Aurangabadkar 《Acta Physiologiae Plantarum》2008,30(5):619-627
The relative water content (RWC), free proline levels and the activities of enzymes involved in proline metabolism were studied
in drought tolerant (Ca/H 680) and drought sensitive (Ca/H 148) genotypes of cotton (Gossypium hirsutum L.) during induction of water stress and posterior recovery. Water stress caused a significant increase in proline levels
and P5CS activity in leaves of both tolerant and sensitive genotypes, whereas the activity of P5CR increased minimally and
the activity of OAT remains unchanged. The activity of PDH decreased under drought stress in both the genotypes. The leaf
of tolerant genotype maintained higher RWC, photosynthetic activity and proline levels, as well as higher P5CS and P5CR activities
under water stress than that of drought sensitive genotype. The drought induced proline levels and activities of P5CS and
P5CR declined and tend to be equal to their respective controls, during recovery, whereas the PDH activity tends to increase.
These results indicate that induction of proline levels by up regulation of P5CS and down regulation of PDH may be involved
in the development of drought tolerance in cotton. 相似文献
19.
Bok-Rye Lee Sowbiya Muneer Sang-Hyun Park Qian Zhang Tae-Hwan Kim 《Acta Physiologiae Plantarum》2013,35(9):2655-2664
Excess of ammonia generates oxidative and osmotic stress, and results in an accumulation of compatible solutes. The aim of this study was to investigate the physiological significance of excess ammonium-induced proline and sucrose accumulation on antioxidative activity and osmotic adjustment. The detached leaves of white clover (Trifolium repense L.) were fed with 0, 10, 50, 100, and 200 mM NH4Cl, and the contribution of proline and sucrose to osmotic adjustment and their relationship with antioxidative enzymes activity were assessed. A gradual decline of relative water content and osmotic potential (Ψπ) with increasing NH4Cl feeding level was accompanied by an increase in ammonia concentration. Significant accumulation of proline and sucrose was observed when NH4Cl was fed over 100 mM compared with control (0 mM NH4Cl). The increase in enzyme activity was significant only at 200 mM for ascorbate peroxidase (APOD) and over 100 mM NH4Cl for guaiacol peroxidase (GPOD) and catalase (CAT). The contribution of proline and sucrose to osmotic adjustment over 100 mM, where proline and sucrose accumulation was more important, maintained at control levels or significantly decreased. The content of proline and sucrose as affected by NH4Cl feeding level was positively related with the activity of APOD, GPOD, and CAT. These results suggest that proline and sucrose accumulation induced by the excess of ammonium has a more influential role in antioxidative activity rather than osmotic adjustment. 相似文献
20.
Effect of osmotic stress and sodium nitroprusside pretreatment on proline metabolism of wheat seedlings 总被引:1,自引:0,他引:1
Effect of osmotic stress and sodium nitroprusside (SNP, NO donor) pretreatment on growth and proline metabolism of wheat seedlings
was investigated. Polyethylene glycol 6000 treatment for 2, 4 and 6 d could be termed as mild, moderate and severe stress,
respectively, according to decrease in the relative water content. Severe osmotic stress significantly decreased the growth
and photochemical efficiency, and increased proline content due to activation of its synthesis. 0.2 mM SNP pretreatment enhanced
growth of wheat seedlings, increased variable to maximum fluorescence ratio (Fv/Fm) and fluorescence yield, while decreased proline content. However, 2 mM SNP retarded the seedlings growth and chlorophyll
a fluorescence, and increased proline accumulation. Our results showed that NO might be involved in the regulation of osmotic
stress in a concentration-dependent manner. 相似文献