Journal of Citrus Pathology

Brazil is one of the largest producers and exporters of citrus. Currently, Huanglongbing disease (HLB) associated to Candidatus Liberibacter asiaticus (CLas) is the main threat to the citrus industry. The aim of this work is to study the genetic transformation of mandarin/mandarin hybrid 'Thomas' (Citrus reticulata Blanco) and 'Fremont' (C. clementina hort. ex Tanaka x C. reticulata Blanco) with the gene that encodes an attacin antibacterial peptide (attA) driven by phloem-specific promoters. The genetic transformation experiments were performed with epicotyl segments, via Agrobacterium tumefaciens (EHA 105), with the gene constructs pCAtSUC2/attA and pCAtPP2/attA, containing the attA gene controlled by AtSUC2 and AtPP2 promoters. Transgenic plants were identified by PCR analysis and acclimatized to greenhouse conditions. The plants will be propagated and evaluated for resistance to CLas.