During the reporting period, we continuously examined the effects of the proposed genes on transient and stable transformation efficiencies of mature and juvenile citrus plant tissues. We now conclude that two of the four genes examined cannot significantly enhance the transformation efficiencies of citrus tissues consistently. The other two genes are still under testing. On other hand, we tested effects of several chemicals on citrus transformation efficiencies, three of the five chemicals tested show 2-3 fold increases in transient and stable transformation efficiency. We are currently testing the effects of their combinations and developing a protocol of incorporating these chemicals in the culture media at various stages. Increases in stable transformation efficiencies of citrus will facilitate the use of transgenic technologies to create HLB resistance traits. Increase in transient expression of the T-DNA genes can help production of non-transgenic CRISPR-mediated mutants using Agrobacterium.