Colorado Native Plant Society Newsletter, Vol. 4 No. 5, September-October 1980

https://epublications.regis.edu/aquilegia/1164/thumbnail.jp

Plastid transformation of high-biomass tobacco variety Maryland Mammoth for production of human immunodeficiency virus type 1 (HIV-1) p24 antigen

Chloroplast transformation of the high-biomass tobacco variety Maryland Mammoth has been assessed as a production platform for the human immunodeficiency virus type 1 (HIV-1) p24 antigen. Maryland Mammoth offers the prospect of higher yields of intact functional protein per unit floor area of contained glasshouse per unit time prior to flowering. Two different transformation constructs, pZSJH1p24 (for the insertion of a native p24 cDNA between the rbcL and accD genes) and pZF5 (for the insertion of a chloroplast-codon-optimized p24 gene between trnfM and trnG) were examined for the production of p24. Plants generated with construct pZSJH1p24 exhibited a normal green phenotype, but p24 protein accumulated only in the youngest leaves (up to approximately 350 microg/g fresh weight or approximately 2.5% total soluble protein) and was undetectable in mature leaves. In contrast, some of the plants generated with pZF5 exhibited a yellow phenotype (pZF5-yellow) with detectable p24 accumulation (up to approximately 450 microg/g fresh weight or approximately 4.5% total soluble protein) in all leaves, regardless of age. Total protein in pZF5-yellow leaves was reduced by approximately 40%. The pZF5-yellow phenotype was associated with recombination between native and introduced direct repeat sequences of the rbcL 3' untransformed region in the plastid genome. Chloroplast-expressed p24 was recognized by a conformation-dependent monoclonal antibody to p24, and p24 protein could be purified from pZF5-yellow leaves using a simple procedure, involving ammonium sulphate precipitation and ion-exchange chromatography, without the use of an affinity tag. The purified p24 was shown to be full length with no modifications, such as glycosylation or phosphorylation, using N-terminal sequencing and mass spectrometry

Age Structure and Successional Dynamics of a Colorado Subalpine Forest

Population age structures of old-growth Engelmann spruce, subalpine fir and lodgepole pine are described in the Colorado Front Range subalpine forest (2850 and 3500 m). Among the populations of these three species, five types of age structures can be recognized; up to four different types of age structures were found in one species under different environmental or historical conditions and no species showed the same type of age structure throughout its entire range of occurrence. The age structures of populations are used to infer their climax or successional (self-replacing of not self-replacing) status. From the combination of climax or successional populations in a stand and the distributions of these combination on environmental gradients, three types of forest are recognized: (1) climax lodgepole; (2) climax spruce-fir, which is pioneered after disturbance by lodgepole; and (3) climax spruce-fir which is pioneered primarily by spruce. The changes from one forest type to another follow a unidimensional gradient which begins with climax lodgepole at low elevation, dry sites, followed by a forest mosaic of successional lodgepole and climax spruce-fir at both higher elevations and intermediate moisture sites, and ends with climax spruce-fir in which lodgepole is not pioneer, at both high elevations and on the most mesic sites

Molecular farming for new drugs and vaccines: Current perspectives on the production of pharmaceuticals in transgenic plants

The European Union Framework 6 Pharma–Planta Consortiu