The project has five objectives:(1) Remove the flowering-promoting CTV and the HLB bacterial pathogen in the transgenic plants(2) Graft CTV- and HLB-free buds onto rootstocks(3) Generate a large number of vigorous and healthy citrus trees(4) Plant the citrus trees in the site secured for testing transgenic citrus for HLB responses(5) Collect the field trial data In this quarter, we have focused on the following three activities: (1) Fourty-nine transgenic plants (30 ‘Hamlin’ sweet orange plants expressing transgene 1, 6 ‘Duncan’ grapefruit plants expressing transgene 1, 6 ‘Duncan’ grapefruit plants expressing transgene 2, 6 ‘Duncan’ grapefruit plants expressing transgene 3, and 1 ‘Duncan’ grapefruit expressing transgene 4) were planted on May 9th, 2019 in the field in Ft Pierce USDA ARS with the help from Dr. Ed Stover. Twenty health plants (10 ‘Hamlin’ plants, 10 grapefruit plants) were purchsed from Briteleaf Nursery and were randomly planted together with the trangenic plants. All plants currently grow vey well and will be analyzed. (2) Continue propagating CTV and CLas free transgenic plants. More budwoods that are negative for CTV and CLas have been grafed onto rootstocks. We will keep propagating plants whenever budwoods are available. The propageted progeny plants will be analyzed for transgene expression by Western blotting. (3) A major citrus defense gene was cloned. This gene is expected to provide resistance or tolerance to HLB when overexpressed in citrus. We plan to generate cisgenic citrus plants using this gene. The full-length cDNA was sequenced and cloned into a bacterial expression vector. We are expressing protein for antibody development. The antibody would be very useful for identifying cisgenic citrus plants that accumulate high levels of the defense gene product, which would help shroten the time-consuming screening process.