Developing of HLB resistance in citrus rootstocks through antimicrobial peptide expression

REYES CARINA ANDREA; CONTI GABRIELA; FURMAN NICOLAS; GOCHEZ ALBERTO; GOMEZ CLAUDIO; GARDELLA VICTORIA; ALMASIA NATALIA; NAHIRÑAK VANESA; VAZQUEZ-ROVERE; KOBAYASH KEN; GARCIA ML; HOPP ESTEBAN; CANTEROS BLANCA

Simposio; IV International Symposium on Citrus Biotechnology; 2018

The disease Huanglongbing (HLB) represents the greatest threat to citrus crop and has resulted in losses of up to 100%. In Argentina, the first diseased plants were detected in Misiones Province in 2012 and currently exceed 200 positive cases including several provinces. The causative agent is a bacterium of the genus Candidatus Liberibacter, which is transmitted by an insect vector present in citrus regions, the Psyllid Diaphorina citri. Among control strategies, genetic engineering techniques appear as very promising, since traditional breeding and alternative management of the Psyllid through application of insecticides has shown to be difficult expensive and inefficient. Citrus plants are mainly propagated by grafting commercial varieties onto rootstocks. The present work shows the generation of transgenic plants of the rootstock Citrange troyer with a construct for the expression of the antimicrobial peptide snakin/GASA that has previously demonstrated to exert direct antimicrobial effects in potato plants. After regeneration, rustication and molecular characterization, the generated transgenic lines will be challenged against bacterial pathogens such as Pseudomonas syringae, Xanthomonas sp and Candidatus Liberibacter. Commercial, non-GMO sweet orange scions will be grafted onto resistant/ tolerant transgenic lines for field-testing to determine if the improved tolerance can also be transmitted to the scion.