Expression of snakin-1 antimicrobial peptide as a strategy for HLB resistance in citrus rootstocks.

GARDELLA, V; HAUTEVILLE, C; GOMEZ, CA; VAZQUEZ ROVERE, CECILIA; GARCIA, ML; CONTI, G; BURDIN, L; ALMASIA N I,; KOBAYASHI, K; HOPP H E; JORIS, G; GOCHEZ, AM; NAHIRÑAK V,; CANTEROS, B; REYES, C

Riverside, California

Congreso; VI IRCHLB Conference.; 2019

IOCV

The disease Huanglongbing (HLB) was first detected in Argentina in MisionesProvince in 2012, and currently exceed 300 positive cases including several provinces.Since 2010 there is a National HLB prevention program (http://www.senasa.gob.ar/hlb)mainly aimed to the phytosanitary control and monitoring tasks as well as diagnosticservices. Among other control strategies for HLB disease, genetic engineering techniquesappear as very promising. Citrus plants are mainly propagated by grafting commercialvarieties onto rootstocks. The present work shows the generation of transgenic plants of oneof the most common rootstocks in Argentina, Citrange troyer [(C. sinensis (L.) Osbeck xPoncirus trifoliata (L.) Raf.] using a construct for the expression of the antimicrobialpeptide snakin-1 (Segura et al., 1999). This peptide was previously demonstrated to exertantimicrobial effects in potato and lettuce plants (Almasia et al., 2008; Darqui et al., 2018).We generated twelve C. troyer transgenic lines that are being rusticated in the greenhouse.Three of the lines were already characterized by molecular analysis and were positive forSnakin-1 expression by RT-PCR and Western blot. Preliminary challenge assays conductedin detached leaves against Xanthomonas sp, revealed a tolerance behavior of the transgeniclines. These lines will be then propagated and challenged against Candidatus Liberibacter.Commercial, non-GMO sweet orange scions will be grafted onto resistant/toleranttransgenic lines for field-testing to determine if the improved tolerance can also betransferred to the scion.