How to drive phloem gene expression? A case study with preferentially expressed citrus gene promoters

Abstract New approaches for developing disease-resistant genetically modified organisms have included specific targets gene expression to enhance the chances pathogen control. Gene driven by phloem-derived Citrus sinensis promoters could be evaluated and compared with induced a strong constitutive promoter in same tissue, leading production of transgenic sweet oranges potentially more resistant diseases caused phloem-limited bacteria. ‘Carrizo’ citrange [ (Poncirus trifoliataL.) Raf. x (L.) Osbeck] was transformed, via Agrobacterium tumefaciens, binary vector pCAMBIA2301 bearing uidA (ß-glucuronidase) CaMV35S (CaMV35S::uidA) or CsPP2.B1 (CsPP2.B1::uidA) CsVTE2 (CsVTE2::uidA) citrus promoters. In vitro regenerated shoots were grafted onto ‘Rangpur’ lime (C. limonia Osbeck). The genetic transformation confirmed Southern blot analyses. RT-qPCR, histolocalization controlled these three accessed X-GLUC treated stem sections. exhibited tissue-specific overall lower than from CaMV35; however, constructs may lead restricted tissues. can considered adequate utilization aiming disease resistance.