Genome-wide analysis of JMJ-C histone demethylase family involved in salt-tolerance in Gossypium hirsutum L

The jumonji C (JMJ-C) domain-containing protein is a histone demethylase and is involved in plant stress. However, the function of the JMJ-C gene family in cotton is still not confirmed. Herein, 25, 26, 52, and 53 members belonging to the JMJ-C gene family were identified in Gossypium raimondii, Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense, respectively. Based on phylogenetic relationships and conserved domains, the JMJ-C genes were categorized into five subfamilies, KDM3, KDM4, KDM5, JMJC, and JMJD6. The chromosomal location, gene structure, motif compositions, and cis-elements have been displayed. The collinear investigation showed that whole-genome duplication event is the mainly power to drive JMJ-C gene family expansion. Transcriptome and qRT-PCR analysis revealed that eight GhJMJs were induced by salt and PEG treatment. Further assays confirmed that GhJMJ34/40 greatly improved salt and osmotic tolerance in Saccharomyces cerevisiae. These results help clarify JMJ-C protein functions in preparation for further study. •A total 156 members of JMJ-C gene family were identified in four Gossypium species.•Expression profile indicated that eight JMJ-C genes respond to salt stress.•GhJMJ34 and GhJMJ40 were proved to regulate salt and mannitol stress in yeast.