Objective Biological characteristics of the gene family related to heat shock transcription factors (HSFs) crucial in plant responses to high-temperature stress in pitaya were studied.

Methods Bioinformatic tools were utilized to analyze the physicochemical properties, motifs, gene structure, domains, chromosome localization, promoters, and phylogenetic tree of the HSF family in Selenicereus spp. Transcriptome and qPCR were employed to determine the gene expressions under heat stress.

Results Thirteen HSFmembers were identified from the genome. The encoded HSFs were all unstableproteins. Most members contained only one intron belonging to 4 classes ofphylogenetics. The genes in the same branch possessed similar or identicalconserved motifs and were randomly distributed in 6 chromosomes. Theirpromoters contained various elements related to the responses to hormone,stress, and light or plant growth and development regulation. The gene structureconsisted of specific domains with temporally and spatially specific expressions.Under high temperature, all HSFs responded significantly but varied intime and level.

Conclusion This studyidentified and validated the involvement of HSF family of pitaya inresponse to heat stress.