Molecular cloning and characterization of ABCG/PDR-type ABC transporter in grape berry skin

Abstract

Grape (Vitis vinifera L.) skin contains the phenolic compound resveratrol which is important not only for resistance to biotic and abiotic stresses but also for human health. However, little is known about resveratrol transport in plant cells. ABC (ATP binding cassette) transporters are well-known transporters responsible for secondary metabolite accumulation in plants. Previous reports speculated that the full-size ABCG transporter pleiotropic drug-resistant (PDR) is involved in resveratrol transport in fungi and plants. In this paper, all full-size ABCG transporters found in the grape genome database are listed and focus is placed on VvABCG44/VvPDR14 as a candidate resveratrol transporter. The full-length cDNA of VvABCG44 was cloned by RT-PCR using mRNAs extracted from grape berry skin. VvABCG44 expression was induced by UV irradiation, and the expression pattern of VvABCG44 in various grape organs was similar to that of stilbene synthase (STS), a key enzyme in resveratrol synthesis. Resveratrol content in grape berry skin increased after UV irradiation. These results suggest that VvABCG44 functions as a resveratrol transporter in grape.

Keywords

• full-size ABCG transporter
• gene expression
• grape
• resveratrol