The overall goal of this project is to understand if a non-transgenic scion can be protected against HLB following budding to a transgenic SAR inducing rootstock. Progress has been made on all proposed objectives according to the time frame. This third quarter report of year 1 funding details progress made so far. All available transgenic lines expressing the AtNPR1 transgene have been evaluated in the laboratory for gene expression using qPCR. We have identified three distinct expression levels – low, medium and high. Selected lines that have a high level of NPR1 expression are also being evaluated by Western Blot using NPR1 specific antibody for confirmation. In some lines there is good corellation between NPR1 production in leaves vs roots while in others root NPR1 production is lower than leaves. Transgenic Kuharske and Swingle rootstock lines that highly express the AtNPR1 transgene have been clonally propagated and budded with non-transgenic Valencia scions. We detected enhanced levels of the PR1 gene following qPCR on the non-transgenic valencia scions. Additional lines are being clonally propagated for budding with non-transgenic Valencia in 2020. A subset of the existing trees is being side grafted with HLB infected budwood (Ct between 22.5 to 25.1) in the greenhouse while another set is being planted out in the field (Obj 1). A USDA-APHIS permit has been obtained for evaluation of these transgenic lines and the first set of trees will be planted in late 2019 (Obj 2). Three additional stacked gene constructs with NPR1 and the other listed genes in the project proposal have been produced and provided to the mature tissue laboratory for production of transgenic rootstocks expressing these transgenes (Obj 3). Trees are being produced with these genetic constructs. AtNPR1 overexpressing seed source trees budded onto US802 rootstock have been produced for field evaluation and will also be planted in late 2019 (Obj. 4). Additionally, transgenic NPR1 lines that have been observed to be tolerant to HLB under field conditions are also being propagated for use as interstocks in this study. In summary, several years of research has resulted in the develoment of this study and our progress thus far has been satisfactory.