DNA technology promises tasty food

February 10, 2008 12:00:00 AM PST
Some produce growers are beginning to use a new DNA technology that promises tastier tomatoes and hardier wheat -- but without genetically altering the plant. Greenhouses in the Davis area are giving a whole new meaning to the word "tilling".

Throughout history, if you wanted to find seeds for the tastiest tomatoes, you'd plant a million of them and taste every one. If you wanted to find the seeds for the crispest apple, you'd plant a million and test them all. The same goes with rice or wheat. It turns out that growers don't need to do all that growing anymore. Thanks to a new technology called tilling.

"We know the relationship between particular genes and particular characteristics -- so, a gene for a particular type of taste, or a gene for a particular color of fruit. And, then, rather than having to grow the plants all the way out, and look at thousands of plants for that, we can screen the plants early in their life. We can screen looking for changes in that gene," says Eric Rey, CEO of Arcadia Biosciences in Davis, California.

At Arcadia, thousands of sample seedlings are grown very quickly under light or chemicals that encourage conventional mutation. Then shoots are snipped, and their DNA extracted. A computer generates these stripes, DNA blots. Each pair of stripes represents a single plant. Any aberration, any variation, means this plant has a special trait. Once an interesting genetic trait is found, that plant is allowed to grow to maturity in a greenhouse. Its seeds can be then be harvested and stored in a library.

A nearby library of tens of thousands of seeds and genes. Want a grain that tolerates salt water? Got it. Need a tomato that stays green longer? Got it. High-throughput genetic screening helps predict which seeds will exhibit which traits, before they grow. Once you know that, you can use the seeds to create hybrids the old fashioned way, cross pollinating.

The name given to this screening technology is "tilling". While some slip into jeans to till the fields, others skip the fields and till the genes.