RNAi Approaches to Plant Pest Control

RNAi Approaches to Plant Pest Control. C. L. Niblett and Ana M. Bailey, Venganza, Inc., Raleigh, NC 27606. niblett@venganzainc.com, 919-995-1643.

Venganza means “revenge” in Spanish. Plants possessing our technology reap revenge on their pests by using the pests’ own genes to control them. It is called gene silencing, or RNA interference (RNAi), and it is a natural process regulating gene expression in plants, animals and other organisms. Each year billions of dollars’ worth of food, feed and fiber crops are lost to plant diseases or the toxins they produce that contaminate food and feed, making it un-consumable and unmarketable. With USAID funding, Venganza is testing RNAi to control important plant diseases with long histories, as well as applying it to new, emerging diseases that are causing serious damage. With the International Potato Center (CIP) in Lima, Peru, we are addressing late blight of potato, which caused the Irish potato famine in 1845, causing millions of Irish to starve or emigrate. It continues to cause major losses worldwide. With the International Center for Maize and Wheat Improvement (CIMMYT) in Mexico City we are addressing stem rust of wheat, once devastating in the US, brought under control, but recently re-emerging in Uganda and the Middle East, and headed for Asia. With Uganda’s National Agricultural Research Organization (NARO) we are addressing black sigatoka and Fusarium wilt, which threaten the extinction of banana, and require fungicidal sprays up to 40 times per year in Latin America. But such fungicides cannot be afforded by the small farmer in Africa, who must utilize inefficient and labor-intensive cultural control methods. Fungi infecting maize, wheat and peanuts produce metabolic byproducts called mycotoxins. They cause illness in man and animals, and several are extremely potent carcinogens. We are addressing those diseases and the mycotoxins with both CIMMYT and NARO. With CIMMYT we also are addressing two important emerging diseases. Wheat blast is becoming very serious in Brazil and neighboring countries, but has not yet been reported in North America, Europe, Africa or Asia. Banded leaf and sheath blight of maize is having an increasing impact on maize production in Asia, especially in China, India and vicinity, and it has been identified in several African and Latin American countries. We also are having success applying RNAi to the control of weevils, which are serious and damaging insect pests of banana, date palm and sweet potato. Descriptions and research updates will be provided for each of these projects.