During the reporting period, we continuously examined the effects of the two proposed genes on transient and stable transformation efficiencies of mature and juvenile citrus plant tissues. The experiments produced mixed results. We are repeating these experiments to obtain more definite conclusions. Two of the many chemicals we have tested consistently display 2-3 fold increases in transient and stable transformation efficiency. Meanwhile, our preliminary results suggest that we can also manipulate and enhance Agrobacterium-mediated transient expression and stable incorporation efficiencies of T-DNA genes. Increase in transient expression of the T-DNA gene expression in citrus tissues could help us to develop a technique to use CRISPR to produce non-transgenic mutants of citrus, which can facilitate the use of CRISPR to produce non-transgenic HLB resistant cultivars of citrus. A manuscript using Agrobacterium-mediated transient expression of CRISPR genes to produce non-transgenic mutants of a model plant species will be submitted for a consideration of publication soon.