The California citrus industry is trying to control the Asian citrus psyllid (ACP), which is the insect that spreads the deadly disease huanglongbing (HLB). The current test that can detect if a tree is infected with the disease has some limitations. The bacteria that causes the disease needs to be contained in the exact location where the samples are taken and sometimes an hlb-positive tree won’t show a positive test.
Research out of UC Riverside might help with earlier detection and Associate Professor Wenbo Ma says instead of looking at the bacteria, their research is looking for what the bacteria produces. The research has identified proteins that the bacteria creates which seem to be easier to find in a tree.
Ma says they are looking to adapt a commonly used tool with other diseases to test for these proteins. This possible new test should also be practical for growers as Ma says it’s an inexpensive process.
Protein secretions may hold the key to early HLB identification
From UC ANR: Because the pathogen that is associated with HLB doesn’t spread throughout infected citrus trees right away, selecting a branch to test is a shot in the dark. Wenbo Ma, associate professor in the Department of Plant Pathology and Microbiology at UC Riverside, believes that the proteins secreted by the bacterium that is associated with HLB are moved rapidly throughout the tree in the phloem, the food-conducting tissue of the plant. Pathogen-specific proteins in the phloem could be a more reliable disease detection tool than the pathogen itself. Ma and her research associates developed a simple and fast method to sample the phloem. “Choose a couple of branches, cut them off and blot the cut ends on filter paper,” she said. “Back in the lab, antibodies are used to detect proteins on the membrane.” Ma has used this disease detection technique successfully to detect citrus stubborn disease. Read more about early detection.