INQUISITION NEWS: Fear not biotechnology, lest we hunger

Of course, there will always be the harbingers of doom who will pontificate against any form of recombinant DNA technology, claiming that it amounts to playing God by interfering with nature and will lead to unforeseen catastrophes. But even the Vatican dismisses this argument. The Pontifical Academy of Scientists has declared that "scientists have both the right and moral duty to be 'stewards of God' by genetically modifying crops to help the world's poor."

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Fear not biotechnology, lest we hunger

By JOE SCHWARCZ, Freelance

I welcomed the International Year of Chemistry at an "all inclusive" resort down south. It featured an amazing variety of foods, as much as you wanted, whenever you wanted. Coming home meant a trip to the supermarket to fill the fridge. Pushing a shopping cart through the aisles, I had my pick of virtually every vegetable I ever heard of, counted more than two dozen varieties of fruits, a dozen types of bread and lost count of the cheeses at 40. This veritable cornucopia has been made possible by today's high-yield farming methods, which owe their success to a number of technologies.

Fritz Haber's synthesis of ammonia from hydrogen and nitrogen in 1909 led the way toward synthetic fertilizers. About 40 years later, Norman Borlaug's crossbreeding of tropical wheat varieties that buckled under the weight of their seeds with sturdy "dwarf " wheat plants produced high-yielding strains that saved millions from famine in the developing world. A vast array of crop protection products has helped ward off the thousands of varieties of insects, fungi and weeds that conspire to reduce yields. But ... and there always is a "but," isn't there?

Farming is not exactly an environmentally friendly business. Amazingly, nitrous oxide and methane emanating from farms are actually bigger culprits as far as global warming goes than the carbon dioxide spewed out by our cars, ships and airplanes. Nitrous oxide is a breakdown product of fertilizers, whether "organic" or "synthetic," and methane is released by livestock, manure and rice paddies in stunning amounts. And of course there is concern about agrochemicals contaminating the environment and possibly affecting our health. These worries, though, are secondary.

Believe it or not, the biggest concern is that by the time 2030 rolls around, farmers may not be able to meet the challenge of increasing agricultural output to meet global needs, in spite of the spectacular advances accomplished by agronomists. It is indeed hard for us in North America to believe this, as our concerns tend to focus on whether blueberries or pomegranates contain more antioxidants, or whether our french fries harbour trans fats. But as the world's population soars to more than 8 billion, the major global issue will be whether farmers can produce the 30 per cent more grain that will be needed, and whether they can accomplish this by using essentially the same amount of land and water as is now devoted to farming. There just isn't much more arable land available -not without destroying more and more wildlife habitats. To top things off, the higher yields will have to be achieved without increasing soil erosion, greenhouse gas output or fresh water requirements.

How is this to be done? Organic agriculture has some desirable features, but will never produce yields that can sustain the world. It is more, not less, technology that is needed. Especially biotechnology. When it comes to coping with low yields due to a lack of water, biotechnology may be an important part of the answer. And answers are needed, given the prediction that climate change will lead to more frequent and more intense dry spells in the coming decades.

Bacillus subtilis bacteria are equipped with a gene that codes for a protein needed to help these microbes cope with the stress induced by cold temperatures. It turns out that this bacterial gene, when inserted into the DNA of corn, helps the crop cope with the stress of drought. The result is an increased yield of about 10 per cent, relative to corn lacking the extra gene.

Another approach involves interfering with the molecular cascade that is initiated by drought. Stressed plants produce ethylene, which in turn triggers the wilting of leaves, impairing photosynthesis. This can be countered by the application of methylcyclopropene, a compound that prevents ethylene from transmitting the stress signal by binding to the plants' ethylene receptors. It has a history of safe use in delaying the natural ripening process in such products as apples, tomatoes, bananas, avocados and melons. Ethylene is produced naturally within the fruit and stimulates ripening -a process that can lead to deterioration during shipping. Overripe fruit becomes inedible, so methylcyclopropene works to extend the food supply in this context as well.

Perhaps the most imaginative technique for increasing the global food supply is to increase the efficiency of photosynthesis, the reaction that makes life on Earth possible. Using chlorophyll as a catalyst to harness the energy of sunlight, plants convert carbon dioxide and water to sugars and starches needed for growth. Photosynthesis can proceed by one of two alternative pathways, termed C3 or C4, depending on whether the first compound forming after carbon dioxide is captured from the air contains three or four carbon atoms.

The C4 process is more efficient, requires less water and produces higher yields. Corn, the main C4 crop, can produce about 50 per cent more grain per acre than wheat or rice, both of which use the C3 photosynthesis pathway. As far as agronomy goes, C3 to C4 conversion is the Holy Grail. If wheat and rice could be genetically modified to utilize the C4 pathway, the increase in yield on a global basis would be enormous. But the challenge is also enormous, with C3 and C4 plants expressing hundreds of genes differently. New technologies for extensive screening of genes may, however, make it possible to identify specific C4 sequences, which could then be incorporated into the genomes of rice or wheat with hopes of inducing C4 photosynthesis.

Of course, there will always be the harbingers of doom who will pontificate against any form of recombinant DNA technology, claiming that it amounts to playing God by interfering with nature and will lead to unforeseen catastrophes. But even the Vatican dismisses this argument. The Pontifical Academy of Scientists has declared that "scientists have both the right and moral duty to be 'stewards of God' by genetically modifying crops to help the world's poor." So, let there be biotechnology. If you are doubtful, just think about the 100 people who have died from hunger while you've been reading this column.