Genome-wide analysis of the ABCB gene family in Vitis vinifera: its expression patterns in berries and its responses to iron and heavy metal stresses

ABSTRACT All living organisms contain ATP-binding cassette (ABC) transporters that perform different biological functions. Here, we identified 19 putative VvABCB from grapevine genomic and proteomic databases. Bioinformatics analyses revealed the phylogenetic relationship, conserved motifs, localisation, and structure of ABCB genes and the regulatory elements in their promoter. Twenty conserved motifs were found among the VvABCB subfamily and their properties were similar to those of ABC transporters. We showed that the VvABCB gene promoters contain many elements related to the light response motif in addition to gibberellin-responsive elements, auxin-responsive elements, and cis-acting element involved in abiotic stresses. The gene expression levels were also analysed at different developmental stages of berries. The transcripts levels of VvABCB genes differed at the various developmental stages of berries, suggesting that they are involved in growth and development. The expression profiles of VvABCB genes obtained via qRT-PCR were used to assess genetic responses to iron and heavy metal stresses. Iron, copper, mercury, and boron induced regulatory responses in VvABCB genes, which likely play a role in coping with iron and heavy metal stresses in plants. This study establishes a base for future functional research on this class of ABC transporters in grapevine.