共查询到20条相似文献,搜索用时 375 毫秒
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Sadeghi A Smagghe G Broeders S Hernalsteens JP De Greve H Peumans WJ Van Damme EJ 《Transgenic research》2008,17(1):9-18
The insecticidal activity of the leaf (ASAL) and bulb (ASAII) agglutinins from Allium sativum L. (garlic) against the cotton leafworm, Spodoptera littoralis Boisd. (Lepidoptera: Noctuidae) was studied using transgenic tobacco plants expressing the lectins under the control of the
constitutive CaMV35S promoter. PCR analysis confirmed that the garlic lectin genes were integrated into the plant genome.
Western blots and semi-quantitative agglutination assays revealed lectin expression at various levels in the transgenic lines.
Biochemical analyses indicated that the recombinant ASAL and ASAII are indistinguishable from the native garlic lectins. Insect
bioassays using detached leaves from transgenic tobacco plants demonstrated that the ectopically expressed ASAL and ASAII
significantly (P < 0.05) reduced the weight gain of 4th instar larvae of S. littoralis. Further on, the lectins retarded the development of the larvae and their metamorphosis, and were detrimental to the pupal
stage resulting in weight reduction and lethal abnormalities. Total mortality was scored with ASAL compared to 60% mortality
with ASAII. These findings suggest that garlic lectins are suitable candidate insect resistance proteins for the control of
S. littoralis through a transgenic approach. 相似文献
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Nagadhara D Ramesh S Pasalu IC Rao YK Sarma NP Reddy VD Rao KV 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(7):1399-1405
Transgenic rice plants, expressing snowdrop lectin [Galanthus nivalis agglutinin (GNA)], obtained by Agrobacterium-mediated genetic transformation, were evaluated for resistance against the insect, the whitebacked planthopper (WBPH). The transgene gna was driven by the phloem-specific, rice-sucrose synthase promoter RSs1, and the bar was driven by the CaMV 35S promoter. In our previous study, the transgenic status of these lines was confirmed by Southern, Northern and Western blot analyses. Both the transgenes, gna and bar, were stably inherited and co-segregated into progenies in T1 to T5 generations. Insect bioassays on transgenic plants revealed the potent entomotoxic effects of GNA on the WBPH. Also, significant decreases were observed in the survival, development and fecundity of the insects fed on transgenic plants. Furthermore, intact GNA was detected in the total proteins of WBPHs fed on these plants. Western blot analysis revealed stable and consistent expression of GNA throughout the growth and development of transgenic plants. Transgenic lines expressing GNA exhibited high-level resistance against the WBPH. As reported earlier, these transgenics also showed substantial resistance against the brown planthopper and green leafhopper . 相似文献
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Andrey Anisimov Kimmo Koivu Anne Kanerva Seppo Kaijalainen Kari Juntunen Viktor Kuvshinov 《Molecular breeding : new strategies in plant improvement》2007,19(3):241-253
The aim of our study was to identify the highest expressing rubisco small subunit (RbcS) promoters (pRbcS) from the cotyledons of germinating seedlings of Brassica rapa var. oleifera to drive high-level and preferably stage-specific transgenic protein expression in Brassicaceae plants. We cloned four new
pRbcS promoters using several approaches, including the construction of a cDNA library and use of genome walking technique. Real-time
PCR analysis of RbcS mRNA expression clearly showed that two of these promoters exhibited the highest activity on the germination stage of plant
development. We used gusA expression as a reporter of promoter activity in Brassica napus and Nicotiana tabacum plants that were transformed with the constructs using an Agrobacterium-mediated transformation strategy. The mRNA level
of RbcS and of gusA was quantified in transformed plants. The data obtained demonstrate that the promoter most active in seedlings under native
conditions was also most active in transgenic constructs at the same stage of plant development. The fine structure of the
promoters is discussed herein. 相似文献
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Chakraborti D Sarkar A Mondal HA Schuermann D Hohn B Sarmah BK Das S 《Plant cell reports》2008,27(10):1623-1633
A binary expression vector was constructed containing the insecticidal gene Allium sativum leaf agglutinin (ASAL), and a selectable nptII marker gene cassette, flanked by lox sites. Similarly, another binary vector was developed with the chimeric cre gene construct. Transformed tobacco plants were generated with these two independent vectors. Each of the T(0) lox plants was crossed with T(0) Cre plants. PCR analyses followed by the sequencing of the target T-DNA part of the hybrid T(1) plants demonstrated the excision of the nptII gene in highly precised manner in certain percentage of the T(1) hybrid lines. The frequency of such marker gene excision was calculated to be 19.2% in the hybrids. Marker free plants were able to express ASAL efficiently and reduce the survivability of Myzus persiceae, the deadly pest of tobacco significantly, compared to the control tobacco plants. Results of PCR and Southern blot analyses of some of the T(2) plants detected the absence of cre as well as nptII genes. Thus, the crossing strategy involving Cre/lox system for the excision of marker genes appears to be very effective and easy to execute. Documentation of such marker excision phenomenon in the transgenic plants expressing the important insecticidal protein for the first time has a great significance from agricultural and biotechnological points of view. 相似文献
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Komeda T Yurimoto H Kato N Sakai Y Kondo K 《Molecular genetics and genomics : MGG》2003,270(3):273-280
The FDH1 gene of Candida boidinii encodes an NAD+-dependent formate dehydrogenase, which catalyzes the last reaction in the methanol dissimilation pathway. FDH1 expression is strongly induced by methanol, as are the promoters of the genes AOD1 (alcohol oxidase) and DAS1 (dihydroxyacetone synthase). FDH1 expression can be induced by formate when cells are grown on a medium containing glucose as a carbon source, whereas expression of AOD1 and DAS1 is completely repressed in the presence of glucose. Using deletion analyses, we identified two cis-acting regulatory elements, termed UAS-FM and UAS-M, respectively, in the 5 non-coding region of the FDH1 gene. Both elements were necessary for full induction of the FDH1 promoter by methanol, while only the UAS-FM element was required for full induction by formate. Irrespective of whether induction was achieved with methanol or formate, the UAS-FM element enhanced the level of induction of the FDH1 promoter in a manner dependent on the number of copies, but independent of their orientation, and also converted the ACT1 promoter from a constitutive into an inducible element. Our results not only provide a powerful promoter for heterologous gene expression, but also yield insights into the mechanism of regulation of FDH1 expression at the molecular level.Communicated by C. P. Hollenberg 相似文献
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Phytochelatins (PCs) are post-translationally synthesized thiol reactive peptides that play important roles in detoxification
of heavy metal and metalloids in plants and other living organisms. The overall goal of this study is to develop transgenic
plants with increased tolerance for and accumulation of heavy metals and metalloids from soil by expressing an Arabidopsis
thaliana
AtPCS1 gene, encoding phytochelatin synthase (PCS), in Indian mustard (Brassica juncea L.). A FLAG-tagged AtPCS1 gDNA, under its native promoter, is expressed in Indian mustard, and transgenic pcs lines have been compared with wild-type
plants for tolerance to and accumulation of cadmium (Cd) and arsenic (As). Compared to wild type plants, transgenic plants
exhibit significantly higher tolerance to Cd and As. Shoots of Cd-treated pcs plants have significantly higher concentrations
of PCs and thiols than those of wild-type plants. Shoots of wild-type plants accumulated significantly more Cd than those
of transgenic plants, while accumulation of As in transgenic plants was similar to that in wild type plants. Although phytochelatin
synthase improves the ability of Indian mustard to tolerate higher levels of the heavy metal Cd and the metalloid As, it does
not increase the accumulation potential of these metals in the above ground tissues of Indian mustard plants. 相似文献
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Salazar M González E Casaretto JA Casacuberta JM Ruiz-Lara S 《Plant cell reports》2007,26(10):1861-1868
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BLT101-family plasma membrane proteins are found in a wide range of organisms from bacteria to nematodes and are involved in the regulation of cellular cation concentration under stress conditions. A comparison of the promoter regions of barley blt101 and its wheat ortholog, wpi6, revealed highly conserved nucleotide sequences between both genes and a unique insertion of a Xumet element in the blt101 promoter. The Xumet insertion occurred between a putative abscisic acid-responsive element (ABRE) and the dehydration-responsive element/c-repeat (DRE/CRT) within the blt101 promoter. However, blt101 and wpi6 were induced similarly in response to ABA, drought and low temperature, suggesting that the insertion does not affect promoter functions. The Xumet insertion in the blt101/wpi6 promoter region was detected in five barley cultivars, but absent in two wheat cultivars tested, suggesting that the insertion is barley-specific. Genomic Southern blot analysis revealed a large number of Xumet sequences interspersed in the barley genome, whereas only one or very few copies are present in the wheat genome. The data suggested that an expansion in copy number of Xumet elements occurred in the barley genome through evolution. 相似文献
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Joon-Seob Eom Cong Danh Nguyen Dae-Woo Lee Sang-Kyu Lee Jong-Seong Jeon 《Journal of Plant Biology》2016,59(3):231-237
Sucrose transporters (SUTs) play a critical role on the phloem plasma membrane in loading sucrose into the phloem of source leaves for long-distance transport to sink organs. Rice has a small gene family of five SUTs, Oryza sativa SUT1 (OsSUT1) to OsSUT5. To identify rice SUTs that function as phloem loaders, we adopted a growth restoration assay of the severe growth retardation phenotype of atsuc2, a mutant of the best-characterized Arabidopsis phloem loader AtSUC2, by introducing OsSUTs. The rice SUT genes were expressed by two different promoters, the native phloem-specific promoter of AtSUC2 (pAtSUC2) and the constitutive Cauliflower Mosaic Virus 35S (pCaMV35S) promoter. Of all the transgenic atsuc2 plants, only pAtSUC2: OsSUT1 complemented the atsuc2 mutant phenotype in a comparable manner to wild type (WT), and consistent levels of soluble sugars and starch were recovered compared to those of WT. This suggests that OsSUT1 is a functional ortholog of the Arabidopsis AtSUC2 and functions as an apoplastic phloem loader. In addition, ossut1 mutants were produced via anther culture and their primary carbohydrate levels and growth phenotypes were indistinguishable from those of WT. This suggests that the rice phloem loader OsSUT1 function may not be essential for rice vegetative growth under normal conditions. 相似文献
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Hennegan K Yang D Nguyen D Wu L Goding J Huang J Guo F Huang N Watkins SC 《Transgenic research》2005,14(5):583-592
Heterologous protein expression levels in transgenic plants are of critical importance in the production of plant-made pharmaceuticals
(PMPs). We studied a puroindoline b promoter and signal peptide (Tapur) driving human lysozyme expression in rice endosperm. The results demonstrated that human lysozyme expressed under the control
of the Tapur cassette is seed-specific, readily extractable, active, and properly processed. Immuno-electron microscopy indicated that
lysozyme expressed from this cassette is localized in protein bodies I and II in rice endosperm cells, demonstrating that
this non-storage promoter and signal peptide can be used for targeting human lysozyme to rice protein bodies. We successfully
employed a strategy to improve the expression of human lysozyme in transgenic rice grain by combining the Tapur cassette with our well established Gt1 expression system. The results demonstrated that when the two expression cassettes were combined, the expression level of
human lysozyme increased from 5.24 ± 0.34 mg−1 g flour for the best single cassette line to 9.24 ± 0.06 mg−1 g flour in the best double cassette line, indicating an additive effect on expression of human lysozyme in rice grain. 相似文献