The goal of the proposed study is to characterize the effect of using endophytic microbes in controlling HLB. Our hypothesis is the outcome of the interaction among Las, psyllid and citrus is affected by the citrus phytobiome. In order to achieve the goal of this study, the following objectives will be conducted: Objective 1. To characterize the phytobiomes and endophytic microbes from HLB survivor trees and HLB diseased trees. In this objective, we will investigate the phytobiomes and endophytes of survivor trees and HLB diseased trees. Metagenomic approaches will be used to investigate the microbiomes of survivor trees and HLB diseased trees. Metatranscriptomic approach will be employed to characterize the expression profile of the microbiomes of survivor trees and HLB diseased trees. We will culture the most representative or beneficial microbes based on metagenomics information. Objective 2. To illustrate whether the endophytic microbes from survivor trees could efficiently manage citrus HLB. In this objective, we will test whether the endophytic microbes affect citrus attractiveness to psyllids, psyllid feeding, and Las establishment in planta. The endophyte application will be through grafting roots or branches of survivor trees or using cultured representative or beneficial microbes from survivor trees. Grafting allows endophytes in survivor trees to be transmitted to testing trees directly without the culturing step and without risking the loss of microbes that are difficult to cultivate. We have extracted RNA and DNA from the rhizosphere, rhizoplane, and endosphere from healthy and HLB diseased trees. The samples have been sent out for sequencing analysis. We will have a better picture about the microbiome of citrus after analysis of the data.