|De Azevedo, Fernando|
|Mourao-filho, De Assis|
|De Paoli, Luis|
Submitted to: Pesquisa Agropecuaria Brasileira
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2006
Publication Date: 11/1/2006
Citation: De Azevedo, F.A., Mourao-Filho, De A., Schinor, E.H., De Paoli, L.G., Januzzi-Mendes, B.M., Harakava, R., Gabriel, D.W., Lee, R.F. 2006. GUS Gene Expression Driven by A Citrus Promoter in Transgenic Tobacco and 'Valencia' Sweet Orange. Pesquisa Agropecuaria Brasileira, 41:1623-1628. Interpretive Summary: Several important diseases are caused by the xylem-inhabiting bacteria, Xylella fastidiosa, such as Pierce’s disease of grapevine and citrus variegated chlorosis in citrus. Ultimately the best control for diseases caused by X. fastidiosa may be through transgenic host plants, but in order to accomplish this, xylem-expressing promoters are needed. This research was undertaken to explore the feasibility of using a phenylalanine ammonia-lyase gene promoter for expression of the ß-glucuronidase (GUS) gene in xylem tissue of tobacco and citrus.
Technical Abstract: The objective of this work was the transformation of tobacco and ‘Valencia’ sweet orange with the GUS gene driven by the citrus phenylalanine ammonia-lyase (PAL) gene promoter (CsPP). Transformation was accomplished by co-cultivation of tobacco and ‘Valencia’ sweet orange explants with Agrobacterium tumefaciens containing the binary vector CsPP-GUS/2201. After plant transformation and regeneration, histochemical analyses using GUS staining revealed that CsPP promoter preferentially, but not exclusively, conferred gene expression in xylem tissues of tobacco. Weaker GUS staining was also detected throughout the petiole region in tobacco and citrus CsPP transgenic plants.