A reference floral transcriptome of sexual and apomictic Paspalum notatum

JUAN PABLO A. ORTIZ; SANTIAGO REVALE; SIENA, LORENA ADELINA; PODIO, MARICEL; DELGADO LUCIANA; JULIANA, STEIN; OLIVIER LEBLANC; PESSINO, SILIVINA CLAUDIA

BMC GENOMICS

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2017 vol. 18 p. 318 - 332

1471-2164

Background Paspalum notatum Flügge is a subtropical grassnative to South America, which includes sexual diploid and apomictic polyploidbiotypes. In the past decade, a number of apomixis-associated genes werediscovered in this species through genetic mapping and differential expressionsurveys. However, the scarce information on Paspalum sequences availablein public databanks limited annotations and functional predictions for thesecandidates.Results We used a long-read 454/Roche FLX+ sequencingstrategy to produce robust reference transcriptome datasets from florets ofsexual and apomictic Paspalum notatum genotypes and delivered a list oftranscripts showing differential representation in both reproductive types. Rawdata originated from floral samples collected from premeiosis to anthesis wasassembled in three libraries: i) sexual (SEX), ii) apomictic(APO) and iii) global (SEX + APO). A group of physically-supported PaspalummRNA and EST sequences matched with high level of confidence to both sexual andapomictic libraries. A preliminary trial allowed discovery of the whole set ofputative alleles/paralogs corresponding to 23 previously identifiedapomixis-associated candidate genes. Moreover, a list of 3,732 transcripts andseveral co-expression and protein ?protein interaction networks associated withapomixis were identified.ConclusionsThe use of the454/Roche FLX+ transcriptome database will allow the detailed characterizationof floral alleles/paralogs of apomixis candidate genes identified in prior andfuture work. Moreover, it was used to reveal additional candidate genesdifferentially represented in apomictic and sexual flowers. Gene ontology (GO)analyses of this set of transcripts indicated that the main molecular pathwaysaltered in the apomictic genotype correspond to specific biological processes,like biotic and abiotic stress responses, growth, development, cell death andsenescence. This data collection will be of interest to the plant reproductionresearch community and, particularly, to Paspalum breeding projects.