GhCIPK6aincreases salt tolerance in transgenic upland cotton by involving in ROS scavenging and MAPK signaling pathways

Abstract

Background Salt stress is one of the most damaging abiotic stresses in production of Upland cotton (Gossypium hirsutum). Upland cotton is defined as a medium salt-tolerant crop. Salinity hinders root development, shoots growth, and reduces the fiber quality. Results Our previous study verified aGhCIPK6agene response to salt stress inG. hirsutum. The homologs ofGhCIPK6awere analyzed in A(2)(G. arboreum), D-5(G.raimondii), and AD(1)(G. hirsutum) genomes. GhCIPK6a localized to the vacuole and cell membrane. The GhCBL1-GhCIPK6a and GhCBL8-GhCIPK6a complexes localized to the nucleus and cytomembrane. Overexpression ofGhCIPK6aenhanced expression levels of co-expressed genes induced by salt stress, which scavenged ROS and involved in MAPK signaling pathways verified by RNA-seq analysis. Water absorption capacity and cell membrane stability of seeds fromGhCIPK6aoverexpressed lines was higher than that of wild-type seeds during imbibed germination stage. The seed germination rates and seedling field emergence percentages ofGhCIPK6aoverexpressed lines were higher than that of control line under salt stress. Moreover, overexpressing ofGhCIPK6ain cotton increased lint percentage, and fiber length uniformity under salt stress. Conclusions We verified the function ofGhCIPK6aby transformation and RNA-seq analysis.GhCIPK6aoverexpressed lines exhibited higher tolerance to abiotic stresses, which functioned by involving in ROS scavenging and MAPK pathways. Therefore,GhCIPK6ahas the potential for cotton breeding to improve stress-tolerance.