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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wheat (Triticum aestivum) transgenic plants of an important commercial cv (Oasis) was obtained with an efficient and short procedure. First, the optimum conditions for the embryogenic calli generation from immature embryos with a high regeneration percentage were established. The transformation of calli was performed by high velocity microprojectile bombardment, using the pAHC25 plasmid, which contains the reporter gene beta-glucuronidase (GUS) and the selectable BAR gene which confers resistance to the herbicide Basta. The transformations were confirmed by beta-glucuronidase assay activity, PCR and Southern blot analysis. The efficiency of this procedure was high and similar to other reports in which "model" cultivar was used.
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PMID:Transgenic wheat plants resistant to herbicide BASTA obtained by microprojectile bombardment. 1224 May 55

Direct DNA delivery procedures (include biolistics method) often resulted in multiple copies of the transgenes in transformants and certain copies of them were rearranged. Integration of multiple copies of the introduced genes was the main reason of gene silencing which meant inhibition or loss of foreign gene expression in filial generations of transformants. In the present work, we compared the influences of maize Ubi-1 promoter and other promoters on copy number of transgenes in maize transgenic plants. Immature embryos from Zea mays L. plants of sib-pollinated of A188 x H99 genotype were used as initial materials. Type- I embryonic calluses derived from preculture of immature embryos were treated on N6 medium containing 0.6 mol/L sucrose for 3 approximately 5 hours and transformed via particle bombardment with PDS1000/He delivery system (Bio-Rad). Bombarded calluses were treated with hyperosmotic N6 medium for 16 approximately 20 hours continuously. Then the cultures were transferred onto normal N6 medium and incubated at 26 degrees C in dark for two weeks and subsequently selected on N6 medium supplemented with 2 or 5 mg/L phosphinothricin (PPT) but without casamino acid for another two weeks. The calluses after selective culture were transferred onto hormone-free MS medium containing 2 or 5 mg/L PPT but without casamino acid, and incubated at 24 degrees C under 16 h illumination for plant regeneration. Regenerated plantlets over 2 cm in height were transferred to Magenta box containing 1/2 hormone-free MS medium. Plantlets over 8 cm in height were transplanted to soil. After growing for one week in greenhouse, the plants were sprayed with 250 mg/L PPT solution. Fertile transgenic maize plants were regenerated and confirmed by Southern blotting and histochemical localization of beta-glucuronidase (GUS) activity. Relations between promoter and copy number of transgenes in transformants were analyzed. Maize transgenic plants possessing an intact copy and another incomplete copy of beta-glucuronidase gene (gus) were obtained in case gus gene under the control of maize Ubi-1 promoter (pUbi:GUS). Simultaneously the co-transformed phosphinothricin acetyltransferase gene (bar) controlled by CaMV 35S promoter in another plasmid (p35S:BAR) also existed with only one copy. When pDB1 and (pUbi:in2) were cobombarded, the regenerated transgenic maize plant exhibited with only one copy of in2 gene too. It suggested that the copy number of transgenes in maize transformants was low if the transgenes controlled by maize Ubi-1 promoter. The possible reason might be that the foreign genes were integrated site-specifically via homologous recombination between Ubi-1 promoter and its endogenous sequences in maize genome, and two cotransformed plasmids had reconstructed as one intact molecule before integrating into maize chromosome. On the contrary, if p35S:BAR was cobom-barded with plasmid pAct:In1 containing rice Act-1 promoter (without maize Ubi-1 promoter), the transgenic maize plants had 4 approximately 8 copies of bar gene. These results reflected that utilization of self gene promoter could reduce the copy number of the transgenes in transgenic plants of certain species itself and avoid the occurrence of gene silencing. T2 seeds have been harvested.
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PMID:[Transgenic maize plants with low copy number of foreign genes were produced with maize Ubi-1 promoter]. 1610 2

Capsella bursa-pastoris is an attractive model system for evolutionary and developmental biology. To facilitate future studies on gene function, the 'floral dip' method was adapted to achieve germline transformation of C. bursa-pastoris. The GFP and BASTA-resistance (BAR (r)) genes were used as markers for screening or selecting, respectively, putative transgenic C. bursa-pastoris plants and the beta-glucuronidase (GUS) gene as well as the GFP gene for monitoring transgene expression level. We tested two Agrobacterium strains, LBA4404 and GV3101, for their ability to transform C. bursa-pastoris. In contrast to Arabidopsis thaliana, for which both strains were able to transform different ecotypes, only GV3101 gave satisfactory transformation rates with C. bursa-pastoris. Furthermore, we evaluated the effects of different concentrations of sucrose and the surfactant Silwet L-77 on the efficiency to generate transgenic C. bursa-pastoris plants and identified an efficient medium containing 10% (w/v) sucrose and 0.02-0.05% (v/v) Silwet L-77. Using Southern hybridisation, we confirmed the integration of the marker gene in the plant genome and the stable heredity of the introduced genes in the next generation.
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PMID:Germline transformation of Shepherd's purse (Capsella bursa-pastoris) by the 'floral dip' method as a tool for evolutionary and developmental biology. 1816 59