Identification of TPS and TPP gene families in Cannabis sativa and their expression under abiotic stresses

Trehalose is a nonreducing disaccharide that is involved in the regulation of plant responses to a variety of environmental stresses. Trehalose 6-phosphate synthase (TPS) and trehalose 6-phosphate phosphatase (TPP) are two key enzymes in trehalose synthesis and they are widely distributed in higher plants. At present, TPS family genes have been systematically identified and analyzed in many plant species, but the TPP family genes have been rarely studied. In this study, ten TPS and six TPP genes in cannabis (Cannabis sativa L.) were identified at the genomic level. The phylogenetic tree of TPS and TPP family members in cannabis, Arabidopsis, and rice was constructed, and all the genes were divided into three subgroups: Class I, Class II, and Class III. The number of exons and motif types among Class I members was exactly the same, as were Class II members, but the gene structure and motif types of Class III members were slightly different. There were four pairs of CsTPSs and CsTPPs that had gene duplication, indicating that gene duplication events played an important role in the amplification of TPS and TPP families in cannabis. The results of expression analysis under abiotic stresses showed that 68.75 % of CsTPS and CsTPP genes were significantly induced by at least one abiotic stress. Among these genes, the expression of CsTPS1, CsTPS9, and CsTPPA was highest under at least one abiotic stress. These three genes may play a key role in abiotic stress responses. Most of the CsTPS and CsTPP genes that are closely located in the evolutionary tree have the same or similar functions. To our knowledge, this is the first paper that systematically reports the TPS and TPP gene families in cannabis.