Scientists look to DNA in search for cure to citrus disease

A serious citrus disease is taking over trees in Florida. Citrus greening has no cure, but scientists hope their research will one day lead to the development of a tree that is resistant.

They’re studying a close relative to citrus trees. With those genes, they hope to lay the foundation to make citrus more tolerant and even resistant to diseases like citrus greening.

Orange juice is a staple on breakfast tables, but diseases like citrus greening beat groves and pockets to a pulp.

“Citrus greening has been a very devastating disease for the Florida citrus industry,” said Dr. Fred Gmitter, a citrus breeding and genetics professor with the UF/IFAS Citrus Research and Education Center.

University of Florida scientists and researchers across the country have concentrated their efforts and sequenced the genome of a fruit plant closely related to citrus trees.

“The trifoliate orange has resistance to a number of different diseases, not limited to, but perhaps most importantly, resistance it seems to citrus greening disease,” Gmitter said.

By breaking down what’s in the plant, scientists can try to answer questions about how it resists citrus greening and then use that information to improve other citrus, like oranges and grapefruits.

That’s welcome news for people like Ron Mahan, vice president and CEO of Tamiami Citrus.

“In 2004 to 2005, 2003 range, Florida was producing around 240 million boxes.” He went on to say, “This past year, and this is all really due to greening, this past year, we produced 67 million boxes.”

Once researchers learn what genes from other plants can protect citrus, the benefits can go beyond our state.

“I think they will be very useful for researchers and not only in Florida, but other states and other countries as well,” said Dr. Zhanao Deng, an environmental horticulture professor with the UF/IFAS Gulf Coast Research and Education Center.

The challenge now is to figure out which genes in citrus make them susceptible to diseases. Once scientists knock out the trait they think is behind it, they’ll have to test citrus trees in a greenhouse and then the real world.