Metabolic engineering of micronutrients in crop plants

Micronutrient deficiency is a widespread phenomenon, most prevalent in developing countries. Being causally linked to the occurrence of a range of diseases, it affects billions of people worldwide. Enhancing the content of micronutrients in crop products through biotechnology is a promising technique to fight micronutrient malnutrition worldwide. Micronutrient fortification of food products has been implemented in a number of Western countries, but remains inaccessible for poor rural populations in a major part of the developing world. Moreover, evidence of the negative impacts of this practice on human health, at least for some vitamins, is accumulating. Biofortification of crop plants-the enhancement of vitamins and minerals through plant biotechnology-is a promising alternative or complement in the battle against micronutrient deficiencies. Owing to a growing knowledge about vitamin metabolism, as well as mineral uptake and reallocation in plants, it is today possible to enhance micronutrient levels in crop plants, offering a sustainable solution to populations with a suboptimal micronutrient intake

Determination of five folate monoglutamates in rodent diets

A method for the quantitative determination of folates in rodent diets is very important for correct interpretation of folate intake during feeding trials, given the possible discrepancy between the actual folate concentration in the diet and that mentioned on the product sheet. Liquid chromatography tandem-mass spectrometry is the method of choice to differentiate and quantify the individual folate species present. This discrepancy may be accounted for by, e.g., inaccurate folic acid supplementation and/or the presence of endogenous reduced and substituted folates. We developed a method, validated based on FDA guidelines, that allows the measurement of added and endogenous folates by quantitative determination of 5 folate monoglutamates with linear ranges from 8 mu g to 2 mg/kg feed. This information, combined with feed intake data, allows insight into the actual folate intake in animal feeding studies. The relevance of this method was illustrated by the analysis of several feed samples of varying composition, by the investigation of the effect of casein incorporation, and by evaluating the variability of the folate content between pellets and production batches

New cultivars: Dionaea ‘Mirror’, Sarracenia ‘Mountain Splendor’, Pinguicula Harry Tongue Group, Pinguicula ‘Jannes’, Pinguicula ‘Bettie’

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Present and future of folate biofortification of crop plants

Improving nutritional health is one of the major socio-economic challenges of the 21st century, especially with the continuously growing and ageing world population. Folate deficiency is an important and underestimated problem of micronutrient malnutrition affecting billions of people worldwide. More and more countries are adapting policies to fight folate deficiency, mostly by fortifying foods with folic acid. However, there is growing concern about this practice, calling for alternative or complementary strategies. In addition, fortification programmes are often inaccessible to remote and poor populations where folate deficiency is most prevalent. Enhancing folate content in staple crops by metabolic engineering is a promising, cost-effective strategy to eradicate folate malnutrition worldwide. Over the last decade, major progress has been made in this field. Nevertheless, engineering strategies have thus far been implemented on a handful of plant species only and need to be transferred to highly consumed staple crops to maximally reach target populations. Moreover, successful engineering strategies appear to be species-dependent, hence the need to adapt them in order to biofortify different staple crops with folate.In this paper, the global occurrence of folate deficiency has been mapped and which staple crops could be targeted for folate biofortification and which engineering strategies could be employed have been investigated

Ex-ante evaluation of biotechnology innovations : the case of folate biofortified rice in China

In order to valorize novel biotechnology innovations, there is a need to evaluate ex-ante their market potential. A case in point is biofortification, i.e. the enhancement of the micronutrient content of staple crops through conventional or genetic breeding techniques. In a recent article in Nature Biotechnology, for example, De Steur et al. (2010) demonstrated the large potential consumer health benefits of folate biofortified rice as a means to reduce folate deficiency and Neural-Tube Defects. By focusing on a Chinese high-risk region of Neural-Tube Defects, the current study defines the potential cost-effectiveness of this genetically modified crop where the need to improve folate intake levels is highest. Building on the Disability-Adjusted Life Years (DALY) approach, both the potential health impacts and costs of its implementation are measured and benchmarked against similar innovations. The results show that this transgenic crop could be a highly cost-effective product innovation (US$120.34 -US$ 40.1 per DALY saved) to alleviate the large health burden of folate deficiency and reduce the prevalence of neural-tube birth defects. When compared with other biofortified crops and target regions, folate biofortified rice in China has a relatively high health impact and moderate cost-effectiveness. This research further supports the need for, and importance of ex-ante evaluation studies in order to adequately market and, thus, valorize biotechnology innovations. Although the cost-effectiveness analysis enables to illustrate the market potential of innovative agricultural biotechnology research, further research is required to address policy issues on transgenic biofortification, such as biosafety regulatory requirements

Conceptual framework for ex-ante evaluation at the micro/macro level of GM crops with health benefits

Socio-economic research plays an important role to successfully introduce novel, controversial goods, such as GM food. This review presents a conceptual framework to explore the market potential of GM food with health benefits at both micro and macro level. While the former examines consumer acceptance and willingness-to-pay, the latter assesses the health impacts and cost-effectiveness. Thereby, underlying theories, methods and empirical research underpinning each line of inquiry are reviewed. By compiling results from eight socioeconomic studies, Folate Biofortified Rice is taken as a case to illustrate how the framework contributes to assess its market demand as well as cost-effectiveness

Engineering complex metabolic pathways in plants

Metabolic engineering can be used to modulate endogenous metabolic pathways in plants or introduce new metabolic capabilities in order to increase the production of a desirable compound or reduce the accumulation of an undesirable one. In practice, there are several major challenges that need to be overcome, such as gaining enough knowledge about the endogenous pathways to understand the best intervention points, identifying and sourcing the most suitable metabolic genes, expressing those genes in such a way as to produce a functional enzyme in a heterologous background, and, finally, achieving the accumulation of target compounds without harming the host plant. This article discusses the strategies that have been developed to engineer complex metabolic pathways in plants, focusing on recent technological developments that allow the most significant bottlenecks to be overcome