Identification, characterization, and expression profiles of the GASA genes in cotton

Background:GASA(Giberellic Acid Stimulated in Arabidopsis)gene family plays a crucial role in the phytohormone signaling pathway,growth and development,and stress responses in plants.Many GASA homologs have been identified in various plants.Nevertheless,little is known about these proteins in cotton.Results:In the current study,we identified 19,17,25,33,and 38 GASA genes via genome-wide analyses of Gossypium herbaceum,G.arboreum,G.raimondii,G.barbadense,and G.hirsutum,respectively,and performed comprehensive bioinformatics and expression analyses.According to our results,132 GASA proteins shared similar protein structures and were classified into four groups based on the phylogenetic tree.A synteny analysis suggested that segmental duplication was a key driver in the expansion of the GASA gene family.Meanwhile,the cis-element and protein interaction analyses indicated that GhGASA proteins play a significant role in the hormone responses.Transcriptomic and qRT-PCR(Quantitative real time-polymerase chain reaction)analyses revealed diverse expression profiles of the GhGASA genes in different organs under abiotic stresses,indicating that some GhGASA genes possibly participate in fiber development and abiotic-stress responses.Conclusions:The GASA genes in cotton were systematically identified and analyzed for the first time in this paper,and it suggested that the GASA genes are important to the development and growth of cotton.These results will support future exploration of the functions of GASA genes in cotton.