Cells of yellow-poplar (Liriodendron tulipifera L.) were transformed by direct gene transfer and regenerated into plants by somatic embryogenesis. Plasmid DNA bearing marker genes encoding beta-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) were introduced by microprojectile bombardment into single cells and small cell clusters isolated from embryogenic suspension cultures. The nu...

A continuous spectrophotometric assay has been developed for detecting β-glucuronidase activity. In the assay, Para-nitrophenyl β-D-glucuronide is cleaved to yield a chromophoric product. With the commercial E. coli enzyme, it is demonstrated that the reactions can be continuously monitored by the increase of absorbance at 405 nm. The method is highly sensitive and able to detect less than 1.4 ...

CPT-11 is a widely-used anti-cancer drug that is converted in vivo to its active metabolite, SN-38. In the liver, enzymes detoxify SN-38 by coupling it to a glucuronidate moiety and this inactive compound (SN-38G) is excreted into the gastrointestinal tract. In the intestine, commensal bacteria convert the SN-38G back to the active and toxic SN-38 using bacterial β-glucuronidase enzyme (GUS). T...

A biosensor was developed using a magnetic focusing optical waveguide (glass tubular probe) for the detection of glucuronidase (GUS) from Escherichia coli based on immunomagnetic separation and chemiluminescent measurement. The magnetic focusing resulted in a lower chemiluminescent signal than that obtained without magnetic-focusing, mainly due to the diffusion of the chemiluminescent reaction ...

An efficient variety-independent method for producing transgenic eggplants (Solanum melongena L.) via Agrobacterium tumefaciens-mediated genetic transformation was developed. Two weeks old cotyledon explants were transformed by co-cultivation with Agrobacterium tumefaciens strain LBA4404 harboring a binary vector pVDH65 carrying the reporter gene β-glucuronidase intron (GUS-INT) and the marker ...

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic t...

Investigations were conducted to determine whether induction of PR-1a gene promoter was correlated with systemic resistance, induced by rhizobacteria, against wildfire disease of tobacco. Ten different strains of plant growth-promoting rhizobacteria (PGPR), including the species Bacillus pumilus, Serratia marcescens, Pseudomonas fluorescens, P. putida, Curtobacterium flaccumfaciens, and Bukhold...

An assay to monitor homologous recombination in plant cells has been established by cotransfecting Nicotiana plumbaginifolia protoplasts with different topological forms of plasmids of various deletion mutants of a non-selectable marker gene, the beta-glucuronidase (GUS) gene. Transient GUS enzyme activities were measured by a sensitive assay. In the nuclear DNA of the cotransfected protoplasts...