GM to rescue the hungry?
The world faces a grain shortage in the making, and the use of genetic engineering to make paddy rice more resistant to disease and adverse conditions is a means of addressing the problem.
World population is expected to reach 9 billion by the year 2050, and half the people on our planet depend on rice as their main food staple. Demand grew from 2.56 million metric tons in 1965 to 6 million tons in 2006, and is projected to reach 7.5 million tons by 2020.
Even as populations grow, the global supply of arable land declines due to industrial pollution, desertification, salination (e.g. by accumulation of fertilizer, or by seawater permeation of soil), erosion, and other factors. The question of how to produce enough grains to feed the world is emerging as an enormous challenge. Scientists believe that genetic modification is of key importance in efforts to resolve the grain shortage because it can increase crop yields and lower the cost of cultivation.
Raising crop productivity and improving resistance to diseases and pests will greatly reduce costs by enabling farmers to cut down on the use of chemical herbicides, pesticides, and fertilizers. Statistics indicate that the use of agricultural chemicals dropped by 14% (or 172.5 billion tons) from 1996, when GM crops were first introduced, to 2004.
"Disease and pest resistance is the most important thing here in Taiwan," says Yu. Living as we do on a small, densely populated island with a humid climate and an abundance of diseases and pests, farmers make heavy use of agricultural chemicals. Indeed, they rank No. 1 in Asia on this score. But if we can bring about widespread use of disease-resistant GM crops, explains Yu, we can resolve this longstanding problem.
And improving the resistance of crops to drought, salinity, and cold will increase arable land area, as crops could be planted in locations that were not formerly suitable, such as low-lying coastal zones subject to seawater incursion, for example, or areas with cold weather.
Besides food, many also hope to use GM crops to resolve the energy crisis.
Yu points out that converting the cellulose in crops to biofuels is quite feasible in theory, but the technology is still under development.
Using an architectural analogy, she likens cellulose to steel rebar, while lignin (which fills the spaces in a plant's cell wall between cellulose, hemicellulose, and pectin components) corresponds to the concrete. These two intertwined elements enable a plant to stand up straight, but the "rebar and concrete" just get in the way when we try to extract fuel from biomass. Cellulose has to be removed in order to break down sugar and process it into ethanol. Strong acids, high temperature, and high pressure are required to destroy the "rebar and concrete," but the acids generate pollution, while a huge amount of energy is consumed to produce the high temperature and pressure. The process is neither environmentally friendly nor economic.
So what kind of "smart crops" should we be growing for energy extraction? Yu believes that paddy rice, wheat, and sugarcane can all be modified from head to toe to suit the purpose. With paddy rice, for example, everything other than the edible seeds has always been seen as waste. Indeed, the rice stalk is generally burnt, causing air pollution, but in fact it is high-quality cellulose that in the future promises to be a "star performer" in the biofuels industry.
Rice plant mutations include broadened leaves, bar-shaped spikes, and plump grains.