The main accomplishments during this quarter: We have confirmed the K gene overexpression-mediated improvement on transformation efficiency of a lemon cultivar we used. We have tested the effects of the K gene on genetic transformation efficiencies of 6 citrus cultivars and we observed 3-15 fold increases if compared to our control vector, and 3-11 fold increases if compared to the highest transformation efficiencies of the same cultivars previously reported by others. We have observed and confirmed the stimulatory effects of one non-conventional regulator of gene expression on shoot regeneration efficiencies of some citrus cultivars. We have been testing the effects of that factor and other factors in combinations of the K gene on transformation efficiencies of both mature and juvenile citrus explants and our preliminary results suggest that there are significant improvements in transformation efficiency for both juvenile and mature tissues. We are also repeating the effects of endogenous auxin and the auxin transport on efficiencies of shoot regeneration and Agrobacterium-mediated infection of mature tissues of citrus. One manuscript reporting the drastically improvement of six citrus cultivars including a lemon cultivar has been accepted for publication in “Plant Cell, Tissue and Organ Culture”. The article is currently in the production stage and should be out in either February or March issue.