Inducción de la expresión del gen de resistencia de yuca RXam2 mediante un promotor inducible por tres efectores tipo tal de xanthomonas phaseoli pv. manihotis

Abstract

Xanthomonas phaseoli pv. manihotis (Xpm) is the causal agent of cassava bacterial blight, a disease that can generate considerable losses in this crop. This bacterium possesses effector proteins that are injected into the host cell through the type-three secretion system and that function as virulence factors. Some of these effectors, called TALEs (Transcription-Activator Like Effectors), enter the nucleus of host cells, bind specifically to host DNA sequences, called effector-binding elements (EBEs), and act as transcription factors to modulate host gene expression. The knowledge of the mode of action for TALEs in species as rice has allowed the development of biotechnological strategies to generate broad-spectrum resistance to pathogens. In this study, a trap promoter was developed that is activated by three predominant TALEs in Xpm strains that allow the expression of the resistance gene RXam2(MHV). Our results show that when TALEs 14, 20 and 22 are co-infiltrated with the synthetic promoter that contains the EBEs for this TALEs a hypersensitive response is produced in the infiltrated area in leaves of N. tabacum. These results represent an important achivement for the use of this strategy in future cassava breeding programs.