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At least 1,243 records · Page 69Linked to original sources
PubMed2003

Plant-based vaccines.

Plant systems are reviewed with regard to their ability to express and produce subunit vaccines. Examples of different types of expression systems producing a variety of vaccine candidates are illustrated. Many of these subunit vaccines have been purified and shown to elicit an immune response when injected into animal models. This review also includes vaccines that have been administered orally in a non-purified form as a food or feed product. Cases are highlighted which demonstrate that orally delivered plant-based vaccines can elicit immune responses and in some case studies, confer protection. Examples are used to illustrate some of the inherent advantages of a plant-based system, such as cost, ease of scale-up and convenience of delivery. Also, some of the key steps are identified that will be necessary to bring these new vaccines to the market.

Administration, Oral↗
PubMed2003

Simultaneous transgenic suppression of LePG and LeExp1 influences fruit texture and juice viscosity in a fresh market tomato variety.

Tomatoes are grown for fresh consumption or for processing of the fruit. Some ripening-associated processes of the fruit can either contribute to or degrade attributes associated with both fresh and processing quality. For example, cell wall disassembly is associated with loss of fresh fruit firmness as well as with loss of processed tomato product viscosity. Several enzymes contribute to cell wall polysaccharide disassembly. Polygalacturonase (PG, poly[1,4-alpha-d-galactouronide] glucanohydrolase, EC 3.2.1.15) is among the most abundant polysaccharide hydrolases in ripening tomato fruit and is the major contributor to pectin depolymerization. Expansin (LeExp1) is also abundant in ripening fruit and is proposed to contribute to cell wall disassembly by nonhydrolytic activity, possibly by increasing substrate accessibility to other enzymes. Suppression of either LePG or LeExp1 expression alone results in altered softening and/or shelf life characteristics. To test whether simultaneous suppression of both LePG and LeExp1 expression influences fruit texture in additive or synergistic ways, transgenic Lycopersicon esculentum var. Ailsa Craig lines with reduced expression of either LePG or LeExp1 were crossed. Fruits from the third generation of progeny, homozygous for both transgenic constructs, were analyzed for firmness and other quality traits during ripening on or off the vine. In field-grown transgenic tomato fruit, suppression of LeExp1 or LePG alone did not significantly increase fruit firmness. However, fruits suppressed for both LePG and LeExp1 expression were significantly firmer throughout ripening and were less susceptible to deterioration during long-term storage. Juice prepared from the transgenic tomato fruit with reduced LePG and LeExp1 expression was more viscous than juice prepared from control fruit.

Beverages↗
PubMed2002

Biotechnology: a solution for improving nutrient bioavailability.

Biotechnology strategies are now available to improve the amount and availability of nutrients in plant crops. Those strategies include simple plant selection for varieties with high nutrient density in the seeds, cross-breeding for incorporating a desired trait within a plant, and genetic engineering to manipulate the nutrient content of the plant. In plant cross-breeding, all genes of the parent plants are combined and the progeny have both desirable and undesirable traits. To eliminate undesirable traits, plant breeders "back-cross" the new plant varieties with other plants over several generations. This technique, called hybridization, has been used to create varieties of low-phytate corn, barley, and rice. Using the techniques of genetic engineering, the gene(s) encoding for a desired trait(s) in a plant are introduced in a precise and controlled manner within a relatively short period of time. Golden rice, containing carotenoids, and rice with higher amounts of iron, are two examples of genetically engineered plants for improved nutrition. Genetic engineering has tremendous potential for revolutionizing nutrition. However, public concerns regarding safety, appearance, and ethics must be overcome before these products can be effectively introduced into the food supply.

Biological Availability↗
PubMed1996

Integration and expression of the high-molecular-weight glutenin subunit 1Ax1 gene into wheat.

The unique bread-making characteristic of wheat flour is closely related to the elasticity and extensibility of the gluten proteins stored in the starchy endosperm, particularly the high-molecular-weight glutenin subunits (HMW-GS), which are important in determining gluten and dough elasticity. The quality of wheat cultivars depends on the number and composition of the HMW-GS present. We have introduced the HMW-GS 1Ax1 gene, known to be associated with good bread-making quality, into the Bob White cultivar of wheat (Triticum aestivum L.), in which it is not present in nature, by the biolistic bombardment of cultured immature embryos. Of the 21 independent transformed lines selected, 20 expressed the selectable bar gene, and nine the 1Ax1 gene. The amount of HMW-GS 1Ax1 protein produced in the different transgenic lines varied from 0.6% to 2.3% of the total protein, resulting in an increase of up to 71% in total HMW-GS proteins. The transgenic plants were normal, fertile, and showed Mendelian segregation of the transgenes. The accumulation of HMW-GS 1Ax1 was consistent and stable up to the R3 seed generation. These results demonstrate that it is possible to manipulate both the quantity and quality of HMW-GS, which influence the bread-making quality of wheat.

Biotechnology↗
PubMedDate not supplied

Making the EU "risk window" transparent: the normative foundations of the environmental risk assessment of GMOs.

In Europe, there seems to be widespread, morally based scepticism about the use of GMOs in food production. In response to this scepticism, the revised EU directive 2001/18/EC on the deliberate release into the environment of genetically modified organisms stresses the importance of respecting ethical principles recognized in the Member States. However, the directive fails to reflect the critical role of value judgements in scientific risk assessment and any subsequent approval procedure. In this paper we argue that it is important to make all ethically relevant assumptions involved in the approval procedure transparent and thus available for public scrutiny. Mapping the value judgements that are made in an environmental risk assessment and approval procedure, we describe the political liberal nature of the EU legislation. We then look more closely at the prescriptions for environmental risk assessment and approval of GMOs outlined in the directive. An environmental risk assessment views the world through a "risk window" that only makes visible that which has been predefined as a relevant risk. The importance of the value judgements that define the risk window consists in limiting the information the risk assessment can provide. In the penultimate section of the paper, the significance of the risk window is demonstrated through a case study of the approval of glyphosate resistant fodder beets (Beta vulgaris L. ssp. vulgaris) in Denmark.

Animal Feed↗
PubMed2006

Biofortification of UK food crops with selenium.

Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 microg Se/d respectively, dietary Se intakes in the UK have declined from >60 microg Se/d in the 1970s to 35 microg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se.

Crops, Agricultural↗
PubMed2003

Assessment of protein allergenicity on the basis of immune reactivity: animal models.

Because of the public concern surrounding the issue of the safety of genetically modified organisms, it is critical to have appropriate methodologies to aid investigators in identifying potential hazards associated with consumption of foods produced with these materials. A recent panel of experts convened by the Food and Agriculture Organization and World Health Organization suggested there is scientific evidence that using data from animal studies will contribute important information regarding the allergenicity of foods derived from biotechnology. This view has given further impetus to the development of suitable animal models for allergenicity assessment. This article is a review of what has been achieved and what still has to be accomplished regarding several different animal models. Progress made in the design and evaluation of models in the rat, the mouse, the dog and in swine is reviewed and discussed.

Administration, Oral↗
PubMed2003

An historical perspective from the Green Revolution to the gene revolution.

Since the 1960s conventional crop breeding has increased food production commesurate with the growing population. For agricultural development to continue, the exploitation of greater genetic diversity and modern biotechnology are becoming increasingly important. This article reviews the milestones achieved by the Green Revolution and many of the recent breakthroughs of modern biotechnology.

Agriculture↗
PubMed1985

Potential food safety problems in genetic engineering.

The rapid development of gene technology, exemplified by the recombinant DNA technique and the hybridoma technique, will heavily influence our food supply in the years to come. Fermentation products from genetic-engineered microbials, the microbials themselves and new plant products will create a number of questions concerning the possible pathogenicity, toxicity, and changed nutritional values of such foodstuffs. This is a great challenge not only to the development of new approaches in nutritional toxicology but also to international cooperation in the field because genetic-modified organisms are not expected to recognize human-made trade barriers or borders. Therefore the initiative of OECD establishing an ad hoc group on safety and regulations in biotechnology is greatly acknowledged.

DNA, Recombinant↗
PubMed2005

Real-time polymerase chain reaction based assays for quantitative detection of barley, rice, sunflower, and wheat.

Quality assurance is a major issue in the food industry. The authenticity of food ingredients and their traceability are required by consumers and authorities. Plant species such as barley (Hordeum vulgare), rice (Oryza sativa), sunflower (Helianthus annuus), and wheat (Triticum aestivum) are very common among the ingredients of many processed food products; therefore the development of specific assays for their specific detection and quantification are needed. Furthermore, the production and trade of genetically modified lines from an increasing number of plant species brings about the need for control within research, environmental risk assessment, labeling/legal, and consumers' information purposes. We report here the development of four independent real-time polymerase chain reaction (PCR) assays suitable for identification and quantification of four plant species (barley, rice, sunflower, and wheat). These assays target gamma-hordein, gos9, helianthinin, and acetyl-CoA carboxylase sequences, respectively, and were able to specifically detect and quantify DNA from the target plant species. In addition, the simultaneous amplification of RALyase allowed bread from durum wheat to be distinguished. Limits of detection were 1 genome copy for barley, sunflower, and wheat and 3.3 copies for rice real-time PCR systems, whereas limits of quantification were 10 genome copies for barley, sunflower, or wheat and approximately 100 haploid genomes for rice real-time PCR systems. Real-time PCR cycling conditions of the four assays were stated as standard to facilitate their use in routine laboratory analyses. The assays were finally adapted to conventional PCR for detection purposes, with the exception of the wheat assay, which detects rye simultaneously with similar sensitivity in an agarose gel.

Acetyl-CoA Carboxylase↗
PubMed1999

GM food debate.

Explore the source record for details and available documents.

Animals↗
PubMed1999

GM food debate.

Explore the source record for details and available documents.

Animals↗