THE GREENING CHALLENGE

Researchers Try to Crack Greening With Comparative Genomics

- HEATHER MACHOVINA

CANDIDATUS LIBERIBACTER ASIATICUS (CLas) is the bacterium responsible for causing the devastating Huanglongbing (HLB or citrus greening) disease. Infected trees have poor vegetative growth, fruit drop, low fruit quality, and tree decline.

Scientists are not able to cultivate CLas on its own in a laboratory setting, causing a significant scientific challenge toward effective HLB management. Because scientists can’t isolate the bacterium in culture, they aren’t able to get comprehensive analyses of its functional genomics. This would be done by transferring a clean culture of CLas from the lab to either insect or plant hosts to establish the relationships between the bacterium and disease in citrus. Furthermore, the characterization of hostpathogen interactions and effective screening of antibacterial compounds are not adequate, leaving so much to be learned about the host/vector/ pathogen interactions on this long road to more and better HLB-fighting methods.

Comparative genomics has provided some preliminary insight into the metabolic processes of this citrus greening bacterium. Metabolic processes refer specifically to the breakdown of food and transforming it into energy. University researchers around the country have been working together to find the link between observable metabolic traits and pathogenic traits between CLas and its hosts.