[Transcriptome analysis of Dendrobium officinale exposed to high temperature stress]

This study aims to mine the genes of Dendrobium officinale in response to high temperature stress and explore the molecular mechanism underlying the heat tolerance of D. officinale. In this study, the D. officinale variety "Dahongshe" was exposed to high temperature for 0, 2, 6, and 12 h, and then transcriptome analysis and qPCR were carried out. The transcriptome of each sample was analyzed by high-throughput sequencing. A total of 14 639 transcripts were obtained after the assembly by StringTie, with the lengths ranging from 500 bp to 2 000 bp. A total of 1 858 differentially expressed genes(DEGs) under high temperature stress in D. officinale, including 1 085 genes with upregulated expression and 773 with downregulated expression. The number of DEGs gradually increased over the time of high temperature treatment. GO enrichment analysis showed that the DEGs were mainly concentrated in transmembrane transport, responses to light, temperature, and radiation stimuli, and activity of transcription factors. The KEGG enrichment analysis revealed that the DEGs responding to high temperature stress were mainly in the pathways of endoplasmic reticulum protein processing, phytohormone signaling pathways, and plant-pathogen interaction. qPCR was performed for 12 randomly selected DEGs, and the outcomes proved that the transcriptome data were accurate and reliable. The results provide a theoretical basis for future work on the molecular mechanism of heat tolerance and the breeding of heat-tolerant varieties of D. officinale.