Identification and characterization of raffinose biosynthesis pathway genes in Vitis vinifera

Grape (Vitis vinifera L.) is one of the most important fruit crops that various adverse abiotic stressesnegatively affect its growth and yield. Raffinose is the classe of soluble carbohydrates that biosynthesis ofits starts with activity of galactinol synthase (GolS) enzyme. In the next step, raffinose is made by raffinosesynthase (RfS) activity. More than one isoform of GolS and RfS are found in different plant species that areexpressed in various organs and responds to diverse environmental conditions. In the present investigation,we carried out a whole genome association study to identify the RfS and GolS gene families, proteincharacteristics, conserved motives, cis- element in prometor, gene structure and chromosomal location andduplication in grape by bioinformatics tools. Based on protein sequences of GolS and RfS found in A.thaliana; ۱۵ VvGolS and ۱۰ VvRfS were identified in grapes genome which clustered in five and six groups,respectively. The peptide length of RfS and VvGolS members was predicted from ۳۴۶ to ۷۹۲ and ۱۶۲ to ۵۹۰amino acid residues. Subcellular localization of all VvRfS members’ family was predicted in cytoplasmic,and most of the VvGolS members were also cytoplasmic. VvRfS had at least three motives of raffinosesynthase or seed imbibition protein Sip۱domain. The VvGolS family had contained most similar genestructure compared to VvRfS family. The VvGolS and VvRfS genes families were divided into ten linkagegroups and four segmental duplication and tandem groups. The existence of four main cis-acting elements(ABRE, LTR, HSE and ARE) indicated that raffinose gene family is stimulated in cold, heat and anaerobicconditions. Abiotic stress can regulate the expression of raffinose gene family through binding to these cisactingelements in upstream of VvGolS and VvRfS genes

Keywords:

Abiotic stress , Carbohydrates , Galactinol synthase , Raffinose synthase