Genetically Improved Crops - The Oxford Topic of Food, Politics, and Society - page 64

What could the nature of solutions to these complex dilemmas be? Over the millennia
many technologies for plant breeding have been developed and used to enhance pro-
ductivity of the original coterie of cultivated crops and to bring more into the domes-
tic fold. Significant nutritional improvements have been achieved via modifications
of staple crops (Stein, this volume). In the latter half of the twentieth century, major
improvements in agricultural productivity were largely based on selective breeding
programs for plants and animals, intensive use of chemical fertilizers, pesticides and
herbicides, advanced equipment developments, and widespread irrigation programs.
Though successful in raising productivity, these improvements have brought corre-
sponding problems: a narrower genetic base of crop plants and domestic animals; pests
that are resistant to chemical pesticides; adverse impacts on environmental quality;
and capital-intensive production. From the food deserts of inner cities to actual barren
wastelands of many world regions, access to a sufficient, healthy diet is a challenge.
Innovations in the future will necessarily involve new, science-based products and
processes. This chapter focuses on the frontiers of plant breeding to meet these chal-
lenges, particularly through genetic engineering approaches. First, in the coming gen-
erations of crop plants the biotic-stress tolerance of the present generation is being
supplemented by continuing improvement of agronomic traits such as yield and abiotic
stress resistance. Sustainability is the critical issue for these traits; the environmental
challenges of climate change are addressed in the subsequent section on green biotech-
nology. Green biotechnology's three major contributions toward mitigating the impact
of climate change are greenhouse gas reduction, crop adaptation and protection, and
yield increase in less desirable and marginal soils. Second, the future will see expan-
sion of traits such as improved nutrition and food functionality. Functional food com-
ponents are of increasing interest in the prevention and treatment of a number of the
leading causes of death, including cancer, diabetes, cardiovascular disease, and hyper-
tension. From a health perspective, dietary plant components can be broadly divided
into four main categories, which can be further broken down into positive and nega-
tive attributions for human nutrition: macronutrients (proteins, carbohydrates, lipids
[oils], and fiber); micronutrients (vitamins, minerals, phytochemicals); antinutrients
(substances such as phytate that limit bioavailability of nutrients); and allergens, intoler-
ances, and toxins. Modern molecular approaches can be employed to down-regulate or
even eliminate the genes involved in the metabolic pathways for the production, accu-
mulation, or activation of toxins in plants with positive food and environmental conse-
quences. The conclusion returns to prospects for biotechnology in agriculture.
Developing and commercializing plants with these improved traits involves over-
coming a variety of technical, regulatory, and political challenges. Most of the inno-
vative technologies that have been applied to production agriculture historically
have come into common usage without much controversy or even knowledge by the
average consumer. Biotechnology has faced a different political and social response.
Through social, cultural, and political processes, genetically engineered plants have
been labeled as uniquely and uniformly risky in many parts of the world (Sato,
this volume; Herring 2010). To separate the hype from the panic, it is necessary to