GONZALEZ Ana Maria
Structure, target-specificity and expression of PN_LNC_N13, a long non-coding RNA differentially expressed in apomictic and sexual Paspalum notatum
ANA CLAUDIA OCHOGAVIA; GIULIO GALLA; J.G. SEIJO; GONZALEZ, A.M.; PUPILLI FULVIO ; GIANNI BARCACCIA; EMIDIO ALBERTINI; PESSINO S.C.
PLANT MOLECULAR BIOLOGY
Lugar: Berlin; Año: 2017
Apomixis is a reproduction strategy avoiding sexuality. Apomictic plants set genetically maternal seeds whose embryos derive by parthenogenesis from apomeiotic egg cells and give rise to clonal offspring. Here we present the characterization of two non-coding transcripts, namely N11 andN13, which were identified in differential expression surveys of sexual and apomictic Paspalum notatum plants. Regarding N11, folding predictions revealed secondary structures compatible with microRNA (miRNA) precursors, with a 26 nucleotide-long sequence identical to a protein-coding gene fragmentlocated in a stem (hypothetical targeting site). The processing of this particular fragment was confirmed by small RNA (sRNA) sequencing. Cleavage analyses of the predicted target (N11Tar, a DUFF677-domain N-myristoylome protein) revealed two major decay products only in apomictic plants. RegardingN13, surveys in the NONCODE and NCBI databases indicated similarity with long non coding RNAs (lncRNAs) and occurrence of a 22 nucleotide-long protein coding gene fragment (predicted targeting site). Searches in floral Paspalum sequence databases revealed a family of N13-related lncRNA transcripts and numerous associated sRNAs. The predicted N13 target sequence (N13Tar, an ARR9-like response regulator) displays transcript variants of different size across species and reproductive types.Both N11/N11Tar and N13/N13Tar showed coordinated and differential quantitative expression patterns along apomictic and sexual development. Moreover, in situ hybridization experiments confirmed differential representation in apomictic and sexual plants. Our results suggest that N11 is a pre-miRNA, upregulated in apomictic ovules, which promotes degradation of its target. Contrastingly, N13 is a member of a large family of lncRNAs, which is upregulated in sexual plants.