Genetically Improved Crops - The Oxford Topic of Food, Politics, and Society - page 71

There is also some research in the final abiotic stress focus area: crops adaptable to less
desirable and marginal soils and increased yields in those circumstances. For example, a gene
that produces citric acid in roots can protect plants from soils contaminated with aluminum
because it binds to the contaminant, preventing uptake by the root system (Lopez-Bucio
et al. 2000). Genes such as these can allow crops to be cultivated in hostile soils and tempera-
tures, increasing geographic range while reducing potential impact on fragile ecosystems.
The frontier should not divert attention from existing implications of existing con-
tributions of biotechnologies in the context of climate change. Soil carbon sequestra-
tion will be an important part of any international strategy to mitigate the increase in
atmospheric CO2 concentrations. By adopting more sustainable management prac-
tices, agriculture may play a large part in enhancing soil carbon sequestration across
the globe. One way is by reducing the amount of conventional tillage after long-term
tillage soil carbon stocks are depleted. Glyphosate-tolerant transgenic crops have aided
in this practice. Through reduced till production, this technology allowed significant
reduction in the release of CO2 emissions, which in 2010 was about 23.1 kg, equivalent
to removing twelve million cars from the roads (Brookes and Barfoot 2012). In general,
cultivation is not a sustainable practice. It is energy intensive and exposes soil to wind
and water erosion. It allows rain to compact the soil and increases the oxygen content,
thus allowing organic matter to oxidize away. In turn, lower organic matter in the soil
allows more compaction and more nutrient loss. Additionally, in warmer and drier cli-
mates evaporative water loss may be reduced because residue remains on the soil sur-
face, creating a wetter and cooler soil microclimate.
Nutritional Improvement
Both the panoply of traditional plant breeding tools and modern biotechnology-based
techniques will be required to produce plants with desirable quality traits. Table 3.1 pres-
ents examples of crops that have already been genetically modified with macro- and
micronutrient traits that may provide nutritional benefits (see also Stein, this volume).
While the correlative link between food and health, beyond meeting basic nutrition
requirements, has been unequivocally proven only in a small number of cases, a grow-
ing body of evidence indicates that food components can influence physiological pro-
cesses at all stages of life. Nutrition intervention from a functionality perspective has a
personal dimension. Determining individual response is at least as complex a challenge
as the task of increasing or decreasing the amount of a specific protein, fatty acid, or
other component of the plant itself (Brigelius-Flohe and Joost 2006). Early food regimes
can affect health in later life. For example, as some children who survived famine con-
ditions in certain regions of Africa grew into adults, they battled obesity and related
problems, presumably because the selective advantage of the thrifty gene in their early
food-stressed environment became a hazard during more abundant times, especially if
their adult diets were calorie dense.