Resistance to wheat streak mosaic virus in transgenic wheat engineered with the viral coat protein gene.

Wheat (Triticum aestivum) plants were stably transformed with the coat protein (CP) gene of wheat streak mosaic virus (WSMV) by the biolistic method. Eleven independently transformed plant lines were obtained and five were analyzed for gene expression and resistance to WSMV. One line showed high resistance to inoculations of two WSMV strains.

Extreme resistance to Potato leafroll virus in potato cv. Russet Burbank mediated by the viral replicase gene.

High levels of field resistance to Potato leafroll virus (PLRV; Genus: Polerovirus; Family: Luteoviridae) were achieved by expression of the unmodified, full-length PLRV replicase gene in potato plants cv. Russet Burbank. A high degree of resistance was also achieved, but less frequently, by expression of a truncated construct of the replicase gene.

Field testing for virus resistance and agronomic performance in transgenic plants.

Resistance to specific virus diseases may be added as heritable characteristics to susceptible drop cultivars by transformation of the cultivars with specific virus-derived genes. In practice, however, resistance to the virus varies among transformed plants and transformation often changes cultivar yield and quality characteristics that are agronomically important. Therefore, rigorous selection among hundreds of different transformed plant lines is required to identify lines that are both virus resistant and also conform to or exceed standard characteristics of the original, susceptible cultivar.

Reduced Field Spread of Potato Leafroll Virus in Potatoes Transformed with the Potato Leafroll Virus Coat Protein Gene.

Russet Burbank potato was transformed with plant expression vectors containing the potato leafroll luteovirus (PLRV) coat protein (CP) gene. Transgenic potato lines contained a gene expression cassette with two copies of a PLRV CP gene in which the nucleotide sequence was modified to improve expression of the gene. In addition, the two copies of the PLRV CP gene were each driven by a different promoter.

Characterization of acquired resistance in lesion-mimic transgenic potato expressing bacterio-opsin.

The lesion-mimic mutants of certain plants display necrotic lesions resembling those of the hypersensitive response and activate local and systemic defense responses in the absence of pathogens. We have engineered a lesion-mimic phenotype in transgenic Russet Burbank potato plants through constitutive expression of a bacterio-opsin (bO) proton pump derived from Halobacterium halobium. Transgenic potato plants exhibiting a lesion-mimic phenotype had increased levels of salicylic acid and overexpressed several pathogenesis-related messenger RNAs, all hallmarks of systemic acquired resistance (SAR).

Effects of acute exposure to hyperbaric oxygen on the rheology and morphology of the red blood cells in the rat.

The effects of acute exposure to hyperbaric oxygen (HBO) on the rheology and morphology of red blood cells (RBC) were studied in three groups of Sprague-Dawley rats: a control (CON) group comprised rats not exposed to HBO, a second group was exposed to HBO at 2.8 atm for 6 hr and studied immediately after the exposure (HBO), and a third group was examined after being allowed to recover in room air for 24 hr after exposure to HBO (REC). RBC deformability was assessed by two different techniques, the ektacytometer and the micropore filters.

Cellular deformability of normoxic and hypoxic mammalian red blood cells.

The deformability of red blood cells is important in the microcirculation where capillary diameters are often smaller than those of the red blood cells. In the present study, ektacytometry was used to examine the effect of hypoxia on the deformability of red blood cells from five mammalian species: Human, cat, rat, rabbit, and dog. Deformability was characterized in both normoxic (PO2 = 129 +/- 6 mm Hg) and hypoxic (PO2 = 47 +/- 6 mm Hg) conditions in two different ways.

Broad-spectrum virus resistance in transgenic plants expressing pokeweed antiviral protein.

Exogenous application of pokeweed antiviral protein (PAP), a ribosome-inhibiting protein found in the cell walls of Phytolacca americana (pokeweed), protects heterologous plants from viral infection. A cDNA clone for PAP was isolated and introduced into tobacco and potato plants by transformation with Agrobacterium tumefaciens. Transgenic plants that expressed either PAP or a double mutant derivative of PAP showed resistance to infection by different viruses.

Agrobacterium-mediated transformation of Solanum tuberosum L. cv. 'Russet Burbank'.

Stem sections from shoot cultures maintained in vitro were used to produce transgenic plants of the potato, Solanum tuberosum L. cv. 'Russet Burbank'.

The second amino acid of alfalfa mosaic virus coat protein is critical for coat protein-mediated protection.

Transgenic plants expressing the coat protein (CP) of alfalfa mosaic virus (AIMV) are resistant to infection by AIMV. A mutation was introduced into the second amino acid of the cDNA for the CP of AIMV. Three different transgenic tobacco lines expressing the mutant CP and two different transgenic tobacco lines expressing the wild-type CP at similar levels were challenged with AIMV virions and viral RNA.

Engineering resistance to mixed virus infection in a commercial potato cultivar: resistance to potato virus X and potato virus Y in transgenic Russet Burbank.

Potato virus X (PVX) and potato virus Y (PVY) infection in potato may result in the loss of certification of seed potatoes and affect quality and yield of potatoes in commercial production. We transformed a major commercial cultivar of potato, Russet Burbank, with the coat protein genes of PVX and PVY. Transgenic plants that expressed both CP genes were resistant to infection by PVX and PVY by mechanical inoculation.

Analysis of the mechanism of protection in transgenic plants expressing the potato virus X coat protein or its antisense RNA.

Transgenic tobacco plants engineered to express either the potato virus X (PVX) coat protein (CP+) or the antisense coat protein transcript (CP-antisense) were protected from infection by PVX, as indicated by reduced lesion numbers on inoculated leaves, delay or absence of systemic symptom development and reduction in virus accumulation in both inoculated and systemic leaves. The extent of protection observed in CP+ plants primarily depended upon the level of expression of the coat protein. Plants expressing antisense RNA were protected only at low inoculum concentrations.