Genome-wide identification, classification, and expression analysis of the gene family in pineapple ().

Transcription factors (TFs), such as heat shock transcription factors (HSFs), usually play critical regulatory functions in plant development, growth, and response to environmental cues. However, no HSFs have been characterized in pineapple thus far. Here, we identified 22 genes from the pineapple genome. Gene structure, motifs, and phylogenetic analysis showed that families were distinctly grouped into three subfamilies (12 in Group A, seven in Group B, and four in Group C). The promoters contained various -elements associated with stress, hormones, and plant development processes, for instance, STRE, WRKY, and ABRE binding sites. The majority of were expressed in diverse pineapple tissues and developmental stages. The expression of / and were enriched in the ovules and fruits, respectively. Six genes ( , , , , and ) were transcriptionally modified by cold, heat, and ABA. Our results provide an overview and lay the foundation for future functional characterization of the pineapple gene family.