Transcriptome sequencing revealed the molecular mechanism of response of pearl millet root to heat stress

High temperature is an environmental factor that affects plant growth and productivity. It is very important to study the changes in plant roots under heat stress (HS) to discover key heat response genes and improve the heat tolerance of plants. Pearl millet is utilized for food, livestock feed and bioenergy materials and is highly tolerant to HS. However, research on the response mechanism of pearl millet roots to HS is limited. In this study, we performed physiological index determination and RNA-seq on the roots of pearl millet under HS (40/35 degrees C) at 1, 3 and 7 hr. The number of differentially expressed genes (DEGs) at 3 hr was the highest (8,479), followed by 1 hr (6,250) and 7 hr (5,167). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DEGs revealed that the endoplasmic reticulum (ER) stress and trehalose synthesis pathways were the major responsive pathways after 1 and 3 hr of HS. This study revealed the underlying molecular mechanism of root response to high temperature stress in pearl millet and provided useful information for identifying heat-resistant genes and breeding heat-resistant plants.