Genome-Wide Analysis of the Rad21/REC8 Gene Family in Cotton (Gossypium spp.)

Cohesin is a ring-shaped protein complex and plays a critical role in sister chromosome cohesion, which is a key event during mitosis and meiosis. Meiotic recombination protein REC8 is one of the subunits of the cohesion complex. Although REC8 genes have been characterized in some plant species, little is known about them in Gossypium. In this study, 89 REC8 genes were identified and analyzed in 16 plant species (including 4 Gossypium species); 12 REC8 genes were identified in Gossypium. hirsutum, 11 in Gossypium. barbadense, 7 in Gossypium. raimondii, and 5 in Gossypium. arboreum. In a phylogenetic analysis, the 89 RCE8 genes clustered into 6 subfamilies (I-VI). The chromosome location, exon-intron structure, and motifs of the REC8 genes in the Gossypium species were also analyzed. Expression patterns of GhREC8 genes in various tissues and under abiotic stress treatments were analyzed based on public RNA-seq data, which indicated that GhREC8 genes might have different functions in growth and development. Additionally, qRT-PCR analysis showed that MeJA, GA, SA, and ABA treatments could induce the expression of GhREC8 genes. In general, the genes of the REC8 gene family of cotton were systematically analyzed, and their potential function in cotton mitosis, meiosis, and in response to abiotic stress and hormones were preliminary predicted, which provided an important basis for further research on cotton development and resistance to abiotic stress.