Transcriptome analysis reveals key genes involved in the eggplant response to high-temperature stress

High-temperature stress (HTS) affects the quality and yield of vegetable crops. Eggplant seedlings, flower organs and fruits are affected by HTS. However, the molecular mechanism underlying heat resistance in eggplant remains unclear. A thermotolerant eggplant line, E390, and a thermosensitive eggplant line, HM, were identified in this study. The differences in the physiological indices, chlorophyll fluorescence, and photosynthetic system parameters of the E390 and HM eggplant lines were analysed under HTS. To better study gene expression under HTS, a transcriptome analysis of eggplant leaves subjected to 42 ℃ high-temperature treatment (HTT) for 0, 1, 6, and 12 h was performed. Gene Ontology (GO) enrichment, Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment, and expression trend analysis of the differentially expressed genes (DEGs) identified were performed. The expression patterns of the genes related to transcription factors (TFs), hormones, and heat stress were further analysed. Twenty-three candidate genes responding to HTS were identified. Moreover, their expression patterns were verified by quantitative real-time RTPCR (qRTPCR). Yeast experiment results revealed that HSP70, MYB44, AFP2, HSFA8, EGY3, HSFA3, and TIFY6B might enhance the heat resistance of eggplant. This study provides a reference for further research on the molecular mechanism of eggplant in response to HTS.