Publications

4466

Citrus huanglongbing (HLB) is a destructive disease that causes significant damage to many citrus producing areas worldwide. To date, no strategy against this disease has been established. Inosine 5′-monophosphate dehydrogenase (IMPDH) plays crucial roles in the de novo synthesis of guanine nucleotides. This enzyme is used as a potential target to treat bacterial infection. In this study, the crystal structure of a deletion mutant of CLas IMPDHΔ98-201 in the apo form was determined. Eight known bioactive compounds were used as ligands for molecular docking. The results showed that bronopol and disulfiram bound to CLas IMPDHΔ98-201 with high affinity. These compounds were tested for their inhibition against CLas IMPDHΔ98-201 activity. Bronopol and disulfiram showed high inhibition at nanomolar concentrations, and bronopol was found to be the most potent molecule (Ki = 234 nM). The Ki value of disulfiram was 616 nM. These results suggest that bronopol and disulfiram can be considered potential candidate agents for the development of CLas inhibitors.

The tomato potato psyllid (TPP), Bactericera cockerelli, is a psyllid native to North America that has recently invaded New Zealand and Australia. The potential for economic losses accompanying invasions of TPP and its associated bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), has caused much concern. Here, we employed ecological niche models to predict environments suitable for TPP/CLso on a global scale and then evaluated the extent to which global potato cultivation is at risk. In addition, at a finer scale the risk to the Australian potato acreage was evaluated. A total of 86 MaxEnt models were built using various combinations of settings and climatic predictors, and the best model based on model evaluation metrics was selected. Climatically suitable habitats were identified in Eurasia, Africa, South America, and Australasia. Intersecting the predicted suitability map with land use data showed that 79.06% of the global potato cultivation acreage, 96.14% of the potato production acreage in South America and Eurasia, and all the Australian potato cropping areas are at risk. The information generated by this study increases knowledge of the ecology of TPP/CLso and can be used by government agencies to make decisions about preventing the spread of TPP and CLso across the globe.