Analysis of microRNAs involved in defense response signaling against Xanthomonas spp. in Citrus limon

CHIESA, M.A; TORRES, P.; CAMPOS, L.; ROESCHLIN, R. A.; GERHARD, N.; FILIPPONE, M.P.; CONEJERO, V.; CASTAGNARO, A.; VOJNOV, A.A; GMITTER JR., F; GADEA, J; MARANO, M.R

Valencia

Congreso; Congreso Internacional de Citricultura- Valencia, España; 2012

Instituto valenciano de Investigaciones Agrarias (IVIA)

MicroRNAs (miRNAs) are small conserved noncoding RNAs of ~ 22 nt long that are present in most eukaryotic genomes. They play a fundamental role as negative regulators of target genes, which are involved in different signaling pathways of biological processes, such as development, hormone signaling and response to biotic and abiotic stresses. Citrus spp. is severely afflicted by Asiatic citrus bacterial canker (CBC), a disease caused by Xanthomonas citri subsp. citri (XC). To get insight into the plant defense responses that could ameliorate canker development, we studied C. limon miRNAs expression in the interaction with a highly virulent strain (XC), a non-pathogen strain of citrus (X. campestris pv. campestris, Xcc) and a strain that generates a hypersensitive response (X. fuscans pv aurantiifoli strain C, Xfa-C). The obtained results revealed interesting expression patterns for some of the miRNAs involved in hormone signaling pathways (miR159, miR160, miR167, miR393), oxidative stress (miR398) and cell-wall strengthening (miR408). These miRNAs are presumably regulating target genes involved in signalling pathways important for C. limon resistance. The biological significance of the differential expression of the assayed miRNAs in compatible, incompatible and non-pathogenic interactions is discussed.