Genome-wide identification of GTE family proteins in sugarcane (Saccharum spontaneum) reveals that SsGTEL3a confers drought tolerance

The bromodomain is a highly conserved protein domain that specifically binds to acetylated lysine residues in histones, thereby activating transcription of target genes. Although some progress in Global Transcription Factor Group E (GTE) has been achieved in numerous animals and a few plant species, no systematic analysis of GTE gene families has been reported yet in sugarcane. In our study, 37 GTE and GTE-Like (GTEL) genes were characterized in the Saccharum spontaneum. All SsGTE/SsGTEL members were heterogeneously located on all chromosomes of the sugarcane genome and divided into five groups. Transcriptome data showed that SsGTEL3a was expressed at significantly higher levels under drought stress in drought-resistant varieties than in drought-sensitive varieties. Moreover, the overexpression of SsGTEL3a significantly improved the drought tolerance in Arabidopsis through improving the scavenging ability of reactive oxygen species. Additionally, an interaction between ScFAR1 and SsGTEL3a was identified, with ScFAR1 showing a positive response to drought stress in bacterium. In summary, this systematic analysis of GTE gene family in sugarcane and functional research of SsGTEL3a broadened deeper insight into their evolutionary dynamics and functional properties and provided new candidate genes for drought-resistant molecular breeding of sugarcane.