Characterization of potential defense compound transporters in barley
M. EHLERT (1), H. Nour-Eldin (1), B. Møller (1), M. Lyngkjær (1) (1) Department of Plant and Environmental Sciences, Denmark

Hydroxynitrile glucosides (HNGs) are known in plants as defense compounds against herbivore and pathogen attack and translocation/storage molecules for nitrogen. Barley (Hordeum vulgare) contains five leucine-derived hydroxynitrile glucosides: epiheterodendrin, epidermin, sutherlandin, osmaronin and dihydroosmaronin. The HNGs are restricted to the leaves, where 99% are stored in the epidermis and account for 90% of the soluble carbohydrates. The obligate biotrophic powdery mildew fungus Blumeria graminis f.sp. hordei strictly infects and feeds from epidermal cells suggesting a crucial role of HNGs in the interaction of barley and the fungus. In the barley genome the HNG biosynthesis genes cluster with two transporters belonging to the ABC and MATE families. Those genes are co-regulated with the biosynthesis genes, indicating a potential role of ABC and MATE proteins as HNG transporters. Subcellular localization studies of ABC and MATE proteins are performed using specific antibodies and confocal microscopy. The ecological role of the transporters in the plant-fungus interactions is investigated by examining up- or downregulation of the transporter genes during and after fungal infection. The ABC and MATE genes were successfully cloned into oocyte expression vectors and transporter cRNA will be injected into oocytes along with the five barley HNGs, enabling to disentangle potential roles of the ABC and MATE proteins as HNG importers or exporters and study transporter kinetics.

Abstract Number: P7-166
Session Type: Poster