共查询到20条相似文献,搜索用时 31 毫秒
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Water movement across cellular membranes is regulated largely by a family of water channel proteins called aquaporins (AQPs).
Since several abiotic stresses such as, drought, salinity and freezing, manifest themselves via altering water status of plant
cells and are linked by the fact that they all result in cellular dehydration, we overexpressed an AQP (tonoplast intrinsic
protein) from Panax ginseng, PgTIP1, in transgenic Arabidopsis
thaliana plants to test its role in plant’s response to drought, salinity and cold acclimation (induced freezing tolerance). Under
favorable conditions, PgTIP1 overexpression significantly increased plant growth as determined by the biomass production, and leaf and root morphology.
PgTIP1 overexpression had beneficial effect on salt-stress tolerance as indicated by superior growth status and seed germination
of transgenic plants under salt stress; shoots of salt-stressed transgenic plants also accumulated greater amounts of Na+ compared to wild-type plants. Whereas PgTIP1 overexpression diminished the water-deficit tolerance of plants grown in shallow (10 cm deep) pots, the transgenic plants
were significantly more tolerant to water stress when grown in 45 cm deep pots. The rationale for this contrasting response,
apparently, comes from the differences in the root morphology and leaf water channel activity (speed of dehydration/rehydration)
between the transgenic and wild-type plants. Plants overexpressed with PgTIP1 exhibited lower (relative to wild-type control) cold acclimation ability; however, this response was independent of cold-regulated
gene expression. Our results demonstrate a significant function of PgTIP1 in growth and development of plant cells, and suggest that the water movement across tonoplast (via AQP) represents a rate-limiting
factor for plant vigor under favorable growth conditions and also significantly affect responses of plant to drought, salt
and cold stresses. 相似文献
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Tang Wei Newton Ronald J. 《Molecular breeding : new strategies in plant improvement》2005,16(3):235-246
Mature zygotic embryos of recalcitrant Christmas tree species Fraser fir [Abies fraseri (Pursh) Poir], and Nordmann fir (Abies nordmanniana L.k.), and Virginia pine (Pinus virginiana Mill.) were used as explants for Agrobacterium tumefaciens strain GV3850-mediated transformation using the gfp (green fluorescent protein) gene as a reporter. Factors including media used for inoculation and co-cultivation, concentrations
of acetosyringone, and antibiotics in tissue culture media have been evaluated. A high transformation frequency was obtained
on TE medium containing 50μM acetosyringone and using 500 mg/l timentin to eliminate bacteria. Transient gene expression was
observed in all three Christmas tree species, but transgenic plants were only produced from Virginia pine. Stable integration
and expression of transgenes in the plant genome of Virginia pine was confirmed by polymerase chain reaction (PCR), Southern
and northern blot analyses. These results demonstrated that a stable transformation system has been established in Virginia
pine and this system would provide an opportunity to transfer economically important genes into Christmas tree species. 相似文献
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Guiping Diao Yucheng Wang Chao Wang Chuanping Yang 《Plant Molecular Biology Reporter》2011,29(1):77-87
Plant glutathione S-transferases (GSTs) are involved in protecting plants against both diverse biotic and abiotic stresses. In the present study,
a novel GST gene (LbGST1) was cloned from Limonium bicolor (Bunge) Kuntze (Plumbaginaceae). To characterize its function in salt tolerance, tobacco lines transformed with LbGST1 were generated. Compared with wild-type (WT) tobacco, transgenic plants overexpressing LbGST1 exhibited both GST and glutathione peroxidase activities. Moreover, superoxide dismutase, peroxidase (POD), and catalase
activities in transgenic plants were significantly higher than those in WT plants, particularly when grown under conditions
of salt stress. Similarly, levels of proline in transgenic plants were also higher than those in WT plants grown under NaCl
stress conditions. Whereas, Malondialdehyde contents in transgenic plants were lower than those in WT plants under NaCl conditions.
Furthermore, Na+ content in transgenic plants was lower than that in WT plants under these stress conditions. Subcellular localization analysis
revealed that the LbGST1 protein was localized in the nucleus. These results suggested that overexpression of LbGST1 gene can affect many physiological processes associated with plant salt tolerance. Therefore, we hypothesize that LbGST1 gene can mediate many physiological pathways that enhance stress resistance in plants. 相似文献
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F. A. Azevedo F. A. A. Mourão Filho B. M. J. Mendes W. A. B. Almeida E. H. Schinor R. Pio J. M. Barbosa S Guidetti-Gonzalez H. Carrer E. Lam 《Plant Molecular Biology Reporter》2006,24(2):185-196
Transgenic plants expressing the bacterio-opsin (bO) gene can spontaneously activate programmed cell death (ped) and may enhance broad-spectrum pathogen resistance by activating
an intrinsic defense pathway in plant species such as tobacco and potato. In this work, we produced transgenic Rangpur lime
plants with thebO gene, viaAgrobacterium tumefaciens-mediated transformation, and evaluated these plants forPhytophthora nicotianae resistance. Two transgenic lines were successfully regenerated and transformation was confirmed by GUS activity assay, PCR
analysis, Southern, Northern and Western blot analyses, in addition to detecting the expressed bO protein by an immunological
approach. Evaluation forPhytophthora nicotianae resistance was carried out by plant inoculations with the pathogen and quantification of the affected area. One of the two
transgenic lines showed greater tolerance to the fungal pathogen as compared to the control, with significantly smaller stem
lesions after pathogen challenge. This increase in pathogen tolerance is correlated with a significantly higher level of transgene
expression in this line when compared with the other transgenic line. This is the first report of the introduction of a potentially
important gene into Rangpur lime to provide novel pathogen tolerance. 相似文献
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Bettini P Michelotti S Bindi D Giannini R Capuana M Buiatti M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(5):831-836
The Agrobacterium rhizogenes rolD gene, coding for an ornithine cyclodeaminase involved in the biosynthesis of proline from ornithine, has been inserted in Lycopersicon esculentum cv Tondino with the aim of studying its effects on plant morphological characters including pathogen defense response. The analysis of plants transgenic for rolD did not show major morphological modifications. First generation transgenic plants however were found to flower earlier, and showed an increased number of inflorescences and higher fruit yield. Transformed plants were also analysed for parameters linked to pathogen defense response, i.e. ion leakage in the presence of the toxin produced by the fungus Fusarium oxysporum f. sp. lycopersici, and expression of the pathogenesis-related PR-1 gene. All the plants harbouring the rolD gene were shown to be more tolerant to the toxin in ion leakage experiments, with respect to the untransformed regenerated controls and the cv Tondino. PR-1 gene expression was quantitated by means of real-time PCR both at the basal level and after treatment with salicylic acid, an inducer of Systemic Acquired Resistance. In both cases the amount of PR-1 mRNA was higher in the transgenic plants. It seems therefore that the transformation of tomato plants with rolD could lead to an increased competence for defense response, as shown by toxin tolerance and increased expression of the Systemic Acquired Resistance marker gene PR-1. The results are finally discussed in view of their possible economic relevance.Communicated by G. Wenzel 相似文献
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A phytoene synthase gene SePSY was isolated from euhalophyte Salicornia europaea L. The 1655 bp full-length SePSY has an open reading frame of 1257 bp and encodes a 419-amino acid protein. The overexpression of SePSY enhanced the growth of transgenic Arabidopsis. When the plants were exposed to 100 mM NaCl, the photosynthesis rate and photosystem II activity (Fv/Fm) increased from 92% to 132% and from 9.3% to 16.6% in the transgenic lines than in the wild-type, respectively. The transgenics displayed higher activities of SOD and POD and lower contents of H(2)O(2) and MDA than the WT. In conclusion, the transgenic lines showed higher tolerance to salt stress than WT plants by increased photosynthesis efficiency and antioxidative capacity. This is the first report about improving the salt tolerance by genetic manipulation of carotenoid biosynthesis. 相似文献
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Polyamines promote root elongation and growth by increasing root cell division in regenerated Virginia pine (Pinus virginiana Mill.) plantlets 总被引:1,自引:0,他引:1
Polyamines have been demonstrated to play an important role in adventitious root formation and development in plants. Here,
we present a detailed analysis of influence of exogenously added polyamines on adventitious root development and its relationship
to cold tolerance in Virginia pine (Pinus virginia Mill.). Our results demonstrated that polyamines putrescine (Put), spermidine (Spd), and spermine (Spm) at 0.001 mM improve
rooting frequency and promote root elongation. Put, Spd, and Spm at 0.01–1 mM decrease rooting frequency and reduce root elongation
root elongation. Measurements of diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.4.3.4) activities showed
that higher DAO and PAO enzyme activities were obtained when high concentrations of polyamines were applied and when plantlets
were treated for 5–7 week at 4°C and 16°C. Survival rate of plantlets increased with the treatment of polyamines at low temperature.
Polyamines increased mitotic index of cells in root tips of regenerated plantlet cultured on medium containing 0.001 μM Put,
Spd, or Spm, but did not increase mitotic index in tissues of needle tips of the same plantlets. These results demonstrated
that polyamines promote root elongation and growth by increasing root cell division in regenerated Virginia pine plantlets. 相似文献
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High efficiency inducible gene expression system based on activation of a chimeric transcription factor in transgenic pine 总被引:1,自引:0,他引:1
Inducible gene expression systems are needed in functional genomics of tree species. A glucocorticoid-inducible gene expression system was established in a gymnosperm species Virginia pine (Pinus virginiana Mill.) through Agrobacterium tumefaciens-mediated genetic transformation. The results demonstrate that expression of the m-gfp5-ER reporter gene was tightly controlled and 0.1 microM of the glucocorticoid hormone triamcinolone was able to induce m-gfp5-ER expression in transgenic cells. Differential expression of gfp in transgenic cells induced by different concentrations of triamcinolone was observed and confirmed by Northern Blot analysis and by quantitative green fluorescence analyses with Laser Scanning Microscopy. In transgenic plantlets, triamcinolone was taken up efficiently by roots. Triamcinolone was able to induce m-gfp5-ER activity throughout the whole plant. The phenotype of transgenic plantlets was not affected 6 weeks after treatment with 0.1-10 microM triamcinolone. However, 6-week inductions with 100 microM triamcinolone caused growth retardation and developmental defects, as well as inhibition of root formation and elongation. With careful selection of transgenic lines, the inducible gene expression presented in this study could be a very valuable alternative for functional identification of novel genes in plants, especially in pine. 相似文献
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To investigate the relationship between nuclear factor Y (NF-Y) and stress tolerance in garlic, we cloned a NF-Y family gene AsNF-YC8 from garlic, which was largely upregulated at dehydrate stage. Expression pattern analyses in garlic revealed that AsNF-YC8 is induced through abscisic acid (ABA) and abiotic stresses, such as NaCl and PEG. Compared with wild-type plants, the overexpressing-AsNF-YC8 transgenic tobacco plants showed higher seed germination rates, longer root length and better plant growth under salt and drought stresses. Under drought stress, the transgenic plants maintained higher relative water content (RWC), net photosynthesis, lower levels of malondialdehyde (MDA), and less ion leakage (IL) than wild-type control plants. These results indicate the high tolerance of the transgenic plants to drought stress compared to the WT. The transgenic tobacco lines accumulated less reactive oxygen species (ROS) and exhibited higher antioxidative enzyme activities compared with wild-type (WT) plants under drought stress, which suggested that the overexpression of AsNF-YC8 improves the antioxidant defense system by regulating the activities of these antioxidant enzymes, which in turn protect transgenic lines against drought stress. These results suggest that AsNF-YC8 plays an important role in tolerance to drought and salt stresses. 相似文献
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Phytochelatins (PCs) are heavy metal binding peptides that play an important role in sequestration and detoxification of heavy
metals in plants. In this study, our goal was to develop transgenic plants with increased tolerance for and accumulation of
heavy metals from soil by expressing an Arabidopsis
thaliana
AtPCS1 gene, encoding phytochelatin synthase (PCS), in Indian mustard (Brassica juncea L.). A 35S promoter fused to a FLAG–tagged AtPCS1 cDNA was expressed in Indian mustard, and transgenic lines, designated pc lines, were evaluated for tolerance to and accumulation
of Cd and Zn. Transgenic plants with moderate AtPCS1 expression levels showed significantly higher tolerance to Cd and Zn
stress, but accumulated significantly less Cd and Zn than wild type plants in both shoot and root tissues. However, transgenic
plants with highest expression of the transgene did not exhibit enhanced Cd and Zn tolerance. Shoots of Cd-treated pc plants
had significantly higher levels of phytochelatins and thiols than wild-type plants. Significantly lower concentrations of
gluthatione in Cd-treated shoot and root tissues of transgenic plants were observed. Moderate expression levels of phytochelatin
synthase improved the ability of Indian mustard to tolerate certain levels of heavy metals, but at the same time did not increase
the accumulation potential for Cd and Zn. 相似文献
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As one of the largest gene families, F-box domain proteins have been found to play important roles in abiotic stress responses via the ubiquitin pathway. TaFBA1 encodes a homologous F-box protein contained in E3 ubiquitin ligases. In our previous study, we found that the overexpression of TaFBA1 enhanced drought tolerance in transgenic plants. To investigate the mechanisms involved, in this study, we investigated the tolerance of the transgenic plants to oxidative stress. Methyl viologen was used to induce oxidative stress conditions. Real-time PCR and western blot analysis revealed that TaFBA1 expression was up-regulated by oxidative stress treatments. Under oxidative stress conditions, the transgenic tobacco plants showed a higher germination rate, higher root length and less growth inhibition than wild type (WT). The enhanced oxidative stress tolerance of the transgenic plants was also indicated by lower reactive oxygen species (ROS) accumulation, malondialdehyde (MDA) content and cell membrane damage under oxidative stress compared with WT. Higher activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD), were observed in the transgenic plants than those in WT, which may be related to the upregulated expression of some antioxidant genes via the overexpression of TaFBA1. In others, some stress responsive elements were found in the promoter region of TaFBA1, and TaFBA1 was located in the nucleus, cytoplasm and plasma membrane. These results suggest that TaFBA1 plays an important role in the oxidative stress tolerance of plants. This is important for understanding the functions of F-box proteins in plants’ tolerance to multiple stress conditions. 相似文献