Drought resistant tomatoes promise increased yields

By making tomato plants over-express the gene AVP1, which resulted in stronger, larger root systems, the researchers were able to develop roots that make better use of limited water.

"The gene gave us a better root system, and the root system could then take the adjustment to drought stress better and thus grow better,"​ said Dr Kendal Hirschi, a researcher at Texas A&M University's vegetable and fruit improvement centre and Baylor's college of medicine.

Hirschi said that regular or control tomatoes used in the experiment suffered irreversible damage after five days without water. The transgenic tomatoes however, began to show signs of damage after 13 days, but rebounded completely as soon as they were watered, according to the study.

Tomatoes remain one of the most popular vegetables within the food industry. In Europe alone, 8.5 million tons of the fruit are cultivated annually with 1.5 million tons sold directly to the consumer and 7 million are processed for products such as ketchup and sauces.

Tomatoes are also packed with the health-promoting antioxidant lycopene, a carotenoid attracting growing attention in recent years due to research linking it to reduction in cancer risk, especially prostate cancer.

"This technology could ultimately be applied to all crops because it involves the over-expression of a gene found in all plants,"​ said Dr. Roberto Gaxiola, a plant biologist at the University of Connecticut and the lead author of the study.

"It has the potential to revolutionise agriculture and improve food production worldwide by addressing an increasing global concern: water scarcity."​

Gaxiola's findings regarding the use of AVP1 in Arabidopsis to create hardier, more drought resistant plants marks the first time the enhanced gene has been inserted in a commercially viable crop, he said.

The study appears in this week's Proceedings of the National Academy of Sciences.​ The paper notes that drought conditions throughout the world each year carve out a huge amount of food production.

To overcome food shortages, the authors suggest, "it will be necessary to increase the productivity of land already under cultivation and to regain the use of arable land lost to scarce water supplies"​.

Hirschi and Gaxiola worked with Dr Sunghun Park, also of the vegetable and fruit improvement centre.

"Our centre is good at moving genes into the different plants,"​ Hirschi said. "Dr Park's job was to move this gene into the tomato."​

Hirschi, whose main research focus is "boosting nutrients in plants to make them more nutritional for children,"​ said the study now may be tried on other crops. Gaxiola said he already has additional studies under way to demonstrate how this technology applies to other commercial crops.