Characterizing developmental and inducible differentiation between juvenile and adult plants of Aechmea fasciata treated with ethylene by transcriptomic analysis

Aechmea fasciata belongs to the Bromeliaceae. In cultivation of bromeliads, flower-induction by ethylene and the derivative has been one item of conventional technology. Flower-induction of bromeliads by ethylene is age-dependent: adult plants bloom but juvenile plants not. To study age-dependent flower transition induced by ethylene in bromeliads, we treated juvenile and adult plants with ethrel, then constructed two transcriptomes using short read sequencing technology (Illumina). 52,396,972 sequencing raw reads totaling 4.72 Gbp of the juvenile plant sample and 52,560,902 sequencing raw reads totaling 4.73 Gbp of the adult plant sample were assembled de novo into 71,445 unique sequences (i.e. All-Unigene) with a mean length of 461 bp and a total assembly size of 47.9 Mbp. Of all, 35,483 unigenes had significant hits with sequences in the Nr database, 24,409 showed significant similarities to known proteins in the Swiss-Prot database. 13,585 and 18,747 unigenes had significant similarity to existing sequences in the Kyoto encyclopedia of genes and genomes (KEGG) and cluster of orthologous group (COG) databases, respectively. Between two transcriptomes, we found 10,036 differentially expressed genes. Among them, we identified and analyzed 60 gene fragments related to ethylene signaling pathway and flowering process.