[Show abstract][Hide abstract] ABSTRACT: Metabolic engineering in plants can be used to increase the abundance of specific valuable metabolites, but single-point interventions generally do not improve the yields of target metabolites unless that product is immediately downstream of the intervention point and there is a plentiful supply of precursors. In many cases, an intervention is necessary at an early bottleneck, sometimes the first committed step in the pathway, but is often only successful in shifting the bottleneck downstream, sometimes also causing the accumulation of an undesirable metabolic intermediate. Occasionally it has been possible to induce multiple genes in a pathway by controlling the expression of a key regulator, such as a transcription factor, but this strategy is only possible if such master regulators exist and can be identified. A more robust approach is the simultaneous expression of multiple genes in the pathway, preferably representing every critical enzymatic step, therefore removing all bottlenecks and ensuring completely unrestricted metabolic flux. This approach requires the transfer of multiple enzyme-encoding genes to the recipient plant, which is achieved most efficiently if all genes are transferred at the same time. Here we review the state of the art in multigene transformation as applied to metabolic engineering in plants, highlighting some of the most significant recent advances in the field.
Full-text · Article · Oct 2013 · The International journal of developmental biology
[Show abstract][Hide abstract] ABSTRACT: European Union (EU) agricultural policy has been developed in the pursuit of laudable goals such as a competitive economy and regulatory harmony across the union. However, what has emerged is a fragmented, contradictory, and unworkable legislative framework that threatens economic disaster. In this review, we present case studies highlighting differences in the regulations applied to foods grown in EU countries and identical imported products, which show that the EU is undermining its own competitiveness in the agricultural sector, damaging both the EU and its humanitarian activities in the developing world. We recommend the adoption of rational, science-based principles for the harmonization of agricultural policies to prevent economic decline and lower standards of living across the continent.
[Show abstract][Hide abstract] ABSTRACT: Genetically engineered (GE) crops can be used as part of a combined strategy to address food insecurity, which is defined as a lack of sustainable access to safe and nutritious food. In this article, we discuss the causes and consequences of food insecurity in the developing world, and the indirect economic impact on industrialized countries. We dissect the healthcare costs and lost productivity caused by food insecurity, and evaluate the relative merits of different intervention programs including supplementation, fortification and the deployment of GE crops with higher yields and enhanced nutritional properties. We provide clear evidence for the numerous potential benefits of GE crops, particularly for small-scale and subsistence farmers. GE crops with enhanced yields and nutritional properties constitute a vital component of any comprehensive strategy to tackle poverty, hunger and malnutrition in developing countries and thus reduce the global negative economic effects of food insecurity.
Full-text · Article · Feb 2013 · Plant Molecular Biology
[Show abstract][Hide abstract] ABSTRACT: Most glandular tissues comprise polarized epithelial cells organized around a single central lumen. Although there is active research investigating the molecular networks involved in the regulation of lumenogenesis, little is known about the extracellular factors that influence lumen formation and maintenance. Using a three-dimensional culture system of epithelial endometrial cells, we have revealed a new role for pro-inflammatory cytokines such as TNFα and IL1α in the formation and, more importantly, maintenance of a single central lumen. We also studied the mechanism by which glucocorticoids repress TNFα and IL1α expression. Interestingly, regulation of pro-inflammatory cytokine expression and subsequent lumen formation is mediated by estrogen receptor α (ERα) but not by the glucocorticoid receptor. Finally, we investigated the signaling pathways involved in the regulation of lumen formation by pro-inflammatory cytokines. Our results demonstrate that activation of the ERK/MAPK signaling pathway, but not the PI3K/Akt signaling pathway, is important for the formation and maintenance of a single central lumen. In summary, our results suggest a novel role for ERα-regulated pro-inflammatory cytokine expression in lumen formation and maintenance.
Full-text · Article · Feb 2012 · Journal of Cell Science
[Show abstract][Hide abstract] ABSTRACT: ‘Formiguers’ are structures similar to charcoal-kilns that were used to burn piles of biomass with a soil cover in order to produce fertilizers for agricultural plots. Their use was widespread in Spain up to the 1960s and similar structures are still in use in India and Bhutan. Our objective was to study the effects of the ‘formiguer’ on its soil cover in terms of changes in nutrient availability. We built an experimental 0.5-m3 ‘formiguer’ with 68 kg of plant material with a 12% moisture content and 550 kg of soil with a 16% moisture content. The content of organic carbon and mineral nitrogen decreased in the soil cover as a result of burning. After aerobic incubation all samples had a similar content of mineral nitrogen. Exchangeable potassium and total and labile phosphorus increased after burning as a result of the soil cover mixing with the ashes of the biomass as the ‘formiguer’ collapsed during burning in the first two cases, while mineralization of organic compounds produced the increase in labile phosphorus. This input of nutrients for the agricultural plots occurs at a net loss of 0.4–2.5 Mg organic C ha−1. Very small amounts of charcoal were produced and this may be the reason for their low occurrence in soils today. Burning of ‘formiguers’ required the harvest of vegetation from a considerable forest area (10–25 ha per hectare of agricultural land) and represented a significant disturbance of these systems.Research highlights▶ ‘Formiguers’ increase labile phosphorus in the soil cover. ▶ Mineral nitrogen recovers in the soil cover of ‘formiguers’ after initial depletion. ▶ ‘Formiguers’ provide significant inputs of potassium from ashes and char. ▶ A net loss of organic carbon occurs in ‘formiguers’. ▶ Over 15 Mg of biomass were burnt in ‘formiguers’ per hectare of agricultural land.
[Show abstract][Hide abstract] ABSTRACT: Topographic characteristics (altitude asl, size, slope and exposure) in two meadowlands of the Central Spanish Pyrenees were analysed. The management consists of only grazing (without irrigation) or mowing and grazing (with or without irrigation). Grazing animals are cows and sheep but cattle are the more important. The preliminary results suggest that pastures and meadows show similar spatial distribution patterns in both localities. Pasture's size is always larger than meadow's size. Both meadows types (irrigated and not irrigated) have the lowest slop and, in the case of the more intensively managed ones (irrigated) they are situated in the bottom of the valley. The exposure is indifferent to management and is directly related to local hydrologic drainage system of rivers and streams.
[Show abstract][Hide abstract] ABSTRACT: Topographic characteristics (altitude asl, size, slope and exposure) in two meadowlands of the Central Spanish Pyrenees were analysed. The management consists of only grazing (without irrigation) or mowing and grazing (with or without irrigation). Grazing animals are cows and sheep but cattle are the more important.
The preliminary results suggest that pastures and meadows show similar spatial distribution patterns in both localities. Pasture’s size is always larger than meadow’s size. Both meadows types (irrigated and not irrigated) have the lowest slop and, in the case of the more intensively managed ones (irrigated) they are situated in the bottom of the valley. The exposure is indifferent to management and is directly related to local hydrologic drainage system of rivers and streams.