Seed specific expression and analysis of recombinant human adenosine deaminase (hADA) in three host plant species.

The plant seed is a leading platform amongst plant-based storage systems for the production of recombinant proteins. In this study, we compared the activity of human adenosine deaminase (hADA) expressed in transgenic seeds of three different plant species: pea (Pisum sativum L.), Nicotiana benthamiana L.

Changes in the de novo, salvage, and degradation pathways of pyrimidine nucleotides during tobacco shoot organogenesis.

Pyrimidine nucleotide metabolism was studied in tobacco callus cultured for 21days under shoot-forming (SF) and non-shoot-forming (NSF) conditions by following the metabolic fate of orotic acid, a precursor of the de novo pathway, and uridine and uracil, intermediates of the salvage and degradation pathways respectively. Nucleic acid synthesis was also investigated by measuring the incorporation of labeled thymidine into different cellular components. Our results indicate that with respect to nucleotide metabolism, the organogenic process in tobacco can be divided in two "metabolic phases": a de novo phase followed by a salvage phase.

Genetic transformation via somatic embryogenesis to establish herbicide-resistant opium poppy.

A reliable genetic transformation protocol via somatic embryogenesis has been developed for the production of fertile, herbicide-resistant opium poppy plants. Transformation was mediated by Agrobacterium tumefaciens using the pCAMBIA3301 vector, which harbors the phosphinothricin acetyltransferase (pat) gene driven by a tandem repeat of the cauliflower mosaic virus (CaMV) 35S promoter and the beta-glucuronidase (gus) structural gene driven by a single copy of the CaMV 35S promoter between left- and right-border sequences. Co-cultivation of explants and A.

Changes of purine and pyrimidine nucleotide biosynthesis during shoot initiation from epicotyl explants of white spruce (Picea glauca).

Nucleotide metabolism was investigated during white spruce organogenesis by following the metabolic fate of (14)C-labeled adenine, adenosine and inosine, as purine precursors, and orotic acid, uridine, and uracil, as pyrimidine intermediates. Key enzymes of purine and pyrimidine metabolism were also assayed during the organogenic process. White spruce epicotyl explants cultured on shoot-forming (SF) medium had a better ability to utilize adenine and adenosine for nucleotide and nucleic acid synthesis, compared to tissue cultured on non-shoot forming (NSF) medium.

Comparative studies on pyrimidine metabolism in excised cotyledons of Pinus radiata during shoot formation in vitro.

Changes in the pattern of pyrimidine nucleotide metabolism were investigated in Pinus radiata cotyledons cultured under shoot-forming (SF; +N(6)-benzyladenine) and non-shoot-forming (NSF, -N(6)-benzyladenine) conditions, as well as in cotyledons unresponsive (OLD) to N(6)-benzyladenine. This was carried out by following the metabolic fate of externally supplied (14)C-labeled orotic acid, intermediate of the de novo pathway, and (14)C-labeled uridine and uracil, substrates of the salvage pathway. Nucleic acid synthesis was also investigated by following the metabolic fate of (14)C-labeled thymidine during shoot bud formation and development.

Evidence for the monophyletic evolution of benzylisoquinoline alkaloid biosynthesis in angiosperms.

Benzylisoquinoline alkaloids (BIAs) consist of more than 2500 diverse structures largely restricted to the order Ranunculales and the eumagnoliids. However, BIAs also occur in the Rutaceae, Lauraceae, Cornaceae and Nelumbonaceae, and sporadically throughout the order Piperales. Several of these alkaloids function in the defense of plants against herbivores and pathogens--thus the capacity for BIA biosynthesis is expected to play an important role in the reproductive fitness of certain plants.

N-acetyl glutamate kinase from Daucus carota suspension cultures: embryogenic expression profile, purification and characterization.

In Daucus carota, N-acetylglutamate-5-phosphotransferase (NAGK; E.C. 2.

Evidence for the monophyletic evolution of benzylisoquinoline alkaloid biosynthesis in angiosperms.

Benzylisoquinoline alkaloids (BIAs) consist of more than 2500 diverse structures largely restricted to the order Ranunculales and the eumagnoliids. However, BIAs also occur in the Rutaceae, Lauraceae, Cornaceae and Nelumbonaceae, and sporadically throughout the order Piperales. Several of these alkaloids function in the defense of plants against herbivores and pathogens - thus, the capacity for BIA biosynthesis is expected to play an important role in the reproductive fitness of certain plants.

Alterations in pyrimidine nucleotide metabolism as an early signal during the execution of programmed cell death in tobacco BY-2 cells.

Changes in pyrimidine metabolism were investigated during programmed cell death (PCD) of tobacco BY-2 cells, induced by a simultaneous increase in the endogenous levels of nitric oxide (NO) and hydrogen peroxide. The de novo synthesis of pyrimidine nucleotides was estimated by following the metabolic fate of the (14)C-labelled orotic acid, whereas the rates of salvage and degradation pathways were studied by measuring the respective incorporation of (14)C-labelled uridine and uracil under different treatments. Nucleic acid metabolism was also examined using labelled thymidine as a marker.

Pyrimidine nucleotide and nucleic acid synthesis in embryos and megagametophytes of white spruce (Picea glauca) during germination.

Pyrimidine nucleotide synthesis was investigated in isolated germinating zygotic embryos and separated megagametophytes of white spruce by following the metabolic fate of 14C-labelled orotic acid, uridine, and uracil, as well as by measuring the activities of the major enzymes participating in nucleotide synthesis. The rate of nucleic acid synthesis in these tissues was also examined by tracer experiments and autoradiographic studies conducted with labelled thymidine, and by conventional light microscopy. From our results, it emerges that changes in the contribution of the de novo and salvage pathways of pyrimidines play an important role during the initial stages of zygotic embryo germination.