Genome-wide identification and expression analysis of the SNARE genes in Foxtail millet (Setaria italica) reveals its roles in drought stress

SNARE (soluble-N-ethylmaleimide-sensitive-factor accessory-protein receptor) proteins are important for plant growth and development. Based on their role in membrane fusion, SNARE proteins are involved in abiotic stress resistance. Foxtail millet (Setaria italica) is a widely cultivated crop in Asia with high tolerance to drought stress. The investigation focuses on drought stress-related genes like SNARE will help to reveal the mechanism of foxtail millet drought tolerance. In this study, we identified 52 SiSNARE genes in foxtail millet. Phylogenetic analysis, prediction of conserved motif, and gene structure analysis classified these genes into different groups, including 15 Qa-SiSNARE genes, 10 Qb-SiSNARE genes, 9 Qc-SiSNARE genes, 3 Qb + c-SiSNARE genes, and 15 R-SiSNARE genes. In silico transcript level analysis showed some SiSNAREs were tissue or development stage-specific expressed. Two cultivars of foxtail millet, “Jingu21” and “Longgu16”, showed different phenotypes under drought stress. We detected the expression of 52 SiSNARE genes in these two cultivars under drought stress. There were 15 SiSNARE genes up-regulated and 3 genes down-regulated after drought stress in both two cultivars. We also found 6 SiSNARE genes were specifically altered under stress in cultivar “Jingu21”, which showed better drought tolerance. Our results provide genomic information for SiSNARE genes in foxtail millet. Analysis of stress-related gene expression in cultivars with different phenotypes suggests some SiSNARE genes' role in drought stress response. These findings laid a foundation for further SNARE related drought stress research in foxtail millet.