Florida's citrus crops have been suffering at the hands of the highly damaging citrus greening bacteria for the past 10 years, costing the state approximately $3.6 billion in revenues since 2007. Researchers from the University of Florida hope to put a stop to this with their genetically modified citrus trees that possess an enhanced resistance to greening.
"Citrus crop improvement using conventional breeding methods is difficult and time consuming due to the long juvenile phase in citrus, which can vary from four to twelve years," Jude Grosser, co-author of the study, said in a press release. "Improvement of citrus through genetic engineering remains the fastest method for improvement of existing citrus cultivars and has been a key component in the University of Florida's genetic improvement strategy."
The researchers used a gene that they isolated from the Arabidopsis plant to create new trees that possess increased greening resistance and decreased disease severity. In fact, some of these trees remained disease-free even 36 months after being planted in a field with a high amount of diseased trees, according to the press release.
The trees utilize a process called systemic acquired resistance (SAR), which allows them to fend off a wide variety of microorganisms due to the production of anti-pathogen proteins. Interestingly, SAR has also allowed the researchers to produce transgenic canker-resistant trees by artificially introducing DNA from unrelated organisms.
"In addition to inducing resistance to greening, this transgenic line could potentially protect our trees from other important citrus fungal and bacterial diseases such as citrus canker and black spot," said Manjul Dutt, co-author of the study.
The team plans to further their research by transferring the gene that they isolated from the Arabidopsis plant and transfer it into commercial plant varieties and rootstocks that are commonly grown in Florida to continue to combat citric greening bacteria.
The study was published in the journal PLOS One.