What is in this article?:
- Can spinach proteins save the U.S. citrus industry?
- Transgenic trees look healthier
- Florida HLB update
Spinach proteins may hold the key for managing the citrus industry's most damaging disease organism.
ERIK MIRKOV, Texas A&M plant pathologist, Weslaco, Texas, holds a transgenic citrus plant he developed using spinach genes called definsins. In Mirkov’s greenhouse and field trials, the plants are either immune or highly resistant to the citrus disease Huanglongbing, the number one threat to the global citrus industry.
Transgenic trees look healthier
The other test includes transgenic trees planted next to standard citrus trees in a commercial grove. The standard, unprotected trees are HLB infected with symptoms including yellowed shoots and leaves. The transgenic trees appear much healthier.
Laboratory tests confirm the transgenic trees have lower amounts of Liberibacter bacteria.
Mirkov is convinced that the transgenic tree could be a valuable resource to growers to help prevent the spread of HLB. He or his research sponsors make quarterly trips to Washington, DC to share his ongoing findings with the Environmental Protection Agency (EPA) and USDA.
“The EPA understands that HLB is a crisis,” Mirkov told the plant pathology audience.
Mirkov is encouraged by the EPA’s overall positive response to the transgenic research. The agency has made it clear that, in general, transgenic trees must be safe for the environment and the fruit safe for human consumption.
Mirkov and Southern Gardens have studies underway seeking any adverse effects on non-target beneficial organisms, including honeybees.
Mirkov said, “In the long run, I believe EPA and USDA will give approval to proceed forward.”
If approved, Mirkov says the first commercially available transgenic trees could be on the market in two to three years.
Western Farm Press asked Mirkov about any possible consumer backlash over the idea of citrus consumption with a touch of spinach inside.
He responded, “Will my citrus taste like spinach or will my orange juice be green? Of course not. We are talking about a small piece of DNA from spinach placed in citrus.”
All eyes of the U.S. citrus industry are focused on research by Mirkov and others at the university, government, and private sector levels in the U.S. and abroad. Citrus researchers have traveled to HLB-infested citrus regions to learn about this devastating disease.
The western U.S. is the last major citrus-producing region in the world to get HLB.
Florida is the nation’s largest citrus-growing area, mostly oranges for processing into juice. California ranks second where about two-thirds of the citrus is grown for the fresh market. Texas and Arizona, where most fruit is sold fresh, rank third and fourth, respectively.
The California, Arizona, and Texas commercial citrus industries are focused on the Florida experience to learn from its mistakes with the psyllid and disease. The first psyllid was found in Florida in 1997 and quickly spread across the state.