Dynamic transcriptome and co-expression network analysis of the cotton (Gossypium hirsutum) root response to salinity stress at the seedling stage

摘要

Upland cotton (Gossypium hirsutum) is a salt-tolerant crop that can endure high salt concentrations without apparent damage. However, the plant's response to salinity stress is a complex biological process. An analysis of the dynamic changes in transcript profiles will provide a global picture of the cotton response to salinity stress. Here, we monitored the transcriptome changes in two cotton genotypes, the salt-tolerant H15, and sensitive ZM12, at 0, 0.25, 1, 3, 6, 12, 24, and 48 h in roots exposed to 200-mM NaCl. In total, 13,894 and 5057 differentially expressed genes were identified as being involved in salt-stress tolerance in H15 and ZM12, respectively. Of these, 3825 genes were common to both genotypes. A differential expression analysis revealed that the number of differentially expressed genes increased significantly during the first 24 h after the salt-stress treatment and then significantly decreased at 48 h in both genotypes. A transcription factor (TF) analysis revealed three different patterns based on the expression of 45 TFs' families, with the majority of differentially expressed TFs increasing rapidly after the salt-stress treatment in both genotypes. A weighted gene co-expression network analysis showed that two gene modules were related to salinity, and genes in these modules were mainly involved in plant-pathogen interactions, the plant MAPK signaling pathway, and diterpenoid biosynthesis. Our results increase the understanding of cotton metabolic pathways involved in responses to salt stress.