The project has three objectives: (1) Confirm HLB resistance/tolerance in transgenic citrus lines. (2) Determine the chimerism of the HLB-resistant/tolerant transgenic lines. (3) Confirm HLB resistance in citrus putative mutants (nontransgenic lines). For objective 1, we are propagating a number of citrus transgenic lines overexpressing Arabidopsis defense genes. Our previous results indicated that these transgenic lines are likely resistant or highly tolerant to HLB. The progeny plants are growing in the greenhouse. For objective 2, we performed on round of real-time quantitative PCR (qPCR) to determine the chimerism of the HLB-resitant/tolerant transgenic lines. The results showed some of the lines may be chimeric. We are repeating the qPCR experiment. For objective 3, we are propagating the previously generated gamma ray-mutagenized mutant lines that are likely resistant/tolerant to HLB. The progeny plants are growing in the greenhouse.