Resistance to canker disease in transgenic pineapple sweet orange plants by dermaseptin expression

FURMAN, N., KOBAYASHI, K., GARCÍA, M. L. Y MENTABERRY

Potrero de Funes

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Orange production has significant contribution to regional economies of Argentina. Citrus canker disease, caused by the bacterium Xanthomonas axonopodis pv. citri (Xac) is the most important disease of citrus and causes important economic losses worldwide. No natural resistance was found in commercial orange cultivars or feedstock plants. Disease control is limited to agronomical practices and/or eradication of infected individuals. We developed a biotechnological strategy based on the expression of the dermaseptin antimicrobial peptide in transgenic Pineapple sweet orange plants. Pineapple sweet orange and N. benthamiana plants were transformed via the A. tumefaciens protocol to express constitutively a dermaseptin. Bacterial growth inhibition assays were performed in vitro using extracts from transgenic N. benthamiana plants. These assays showed a strong inhibition of Xac growth with every extract tested. In planta assays performed with two selected transgenic Pineapple sweet orange plants showed similar results. Abacterial suspension was sprayed on the surface of punctured leaves (6 punctures per leaf) and canker development was evaluated up to 35 days under a dissecting microscope. Analysis of 70 to 100 punctures per/plant consistently showed lower frequencies of severe canker symptoms in transgenic orange leaves as compared to non-transformed controls.