Genetic transformation of \'Valencia\' sweet orange with the cecropin MB39 gene

The objective of this work was to produce 'Valencia' sweet orange transgenic plants with the cecropin MB39 gene controlled by a phenylalanine ammonia-lyase gene promoter from citrus in order to direct gene expression in xylem vessels. The genetic transformation was mediated by Agrobacterium tumefaciens with the co-culture of epicotyl segments. Eleven transgenic plants were selected by PCR with the amplification of a 189 bp fragment, which were acclimatized to greenhouse. The integration of the transgene was confirmed in three plants by Southern blot analysis.