During the reporting period, we conducted additional experiments to determine effects of the two genes that displayed promotional effects on citrus transformation efficiency. Using RNAi constructs, we demonstrated 2-4 fold increases in Agrobacterium-mediated stable transformation in juvenile explants or a 2-3 fold increase in mature Washington Navel tissues. We also observed that two chemicals added to media increased stable transformation efficiencies by 3-fold. We further showed that three chemicals enhanced transient expression of T-DNA genes, which can be important for using CRISPR to create non-transgenic mutants of citrus. We produced additional independent transgenic citrus plants using the root specific iaaM gene described in the proposal. We also conducted two experiments to compare efficiencies of Agrobacterium- and biolistic-mediated transient expression in citrus tissues. The experiment may provide a basis what method should be preferred for using CRISPR to produce non-transgenic mutants of citrus.