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

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

Valencia

Congreso; XII International Citrus Congress; 2012

MicroRNAs (miRNAs) are small conserved noncoding RNAs of ~ 22 nt long that are present in most eukaryotc genomes. They play a fundamental role as negatve regulators of target genes, which are involved in diferent signaling pathways of biological processes, such as development, hormone signaling and response to biotc and abiotc stresses. Citrus spp. is severely aficted by Asiatc 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 interacton with a highly virulent strain (XC), a non-pathogen strain of citrus (X. campestris pv. campestris, Xcc) and a strain that generates a hypersensitve response (X. fuscans pv aurantifoli strain C, Xfa-C). The obtained results revealed interestng expression paterns for some of the miRNAs involved in hormone signaling pathways (miR159, miR160, miR167, miR393), oxidatve stress (miR398) and cell-wall strengthening (miR408). These miRNAs are presumably regulatng target genes involved in signalling pathways important for C. limon resistance. The biological signifcance of the diferental expression of the assayed miRNAs in compatble, incompatble and non-pathogenic interactons is discussed.