title: Transcript profiling of two potato cultivars during glycoalkaloid-inducing treatments shows differential expression of genes in sterol and glycoalkaloid metabolism.
abstract: Steroidal glycoalkaloids (SGA) are sterol-derived neurotoxic defence substances present in several members of the Solanaceae. In the potato (Solanum tuberosum), high SGA levels may render tubers harmful for consumption. Tuber SGA levels depend on genetic factors, and can increase as a response to certain stresses and environmental conditions. To identify genes underlying the cultivar variation in tuber SGA levels, we investigated two potato cultivars differing in their SGA accumulation during wounding or light exposure; two known SGA-inducing treatments. Using microarray analysis coupled to sterol and SGA quantifications, we identified a small number of differentially expressed genes that were associated with increased SGA levels. Two of these genes, encoding distinct types of sterol Δ24-reductases, were by sense/antisense expression in transgenic potato plants shown to have differing roles in sterol and SGA metabolism. The results show that an increased SGA level in potato tubers during both wounding and light exposure is mediated by coordinated expression of a set of key genes in isoprenoid and steroid metabolism, and suggest that differences in this expression underlie cultivar variations in SGA levels. These results may find use within potato breeding and quality assessment.
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Nurun
authors.initials: N
authors.lastname: Nahar
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Westerberg
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Usman
authors.initials: U
authors.lastname: Arif
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Huchelmann
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Olarte Guasca
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Beste
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Dalman
authors.affiliation: Department of Food Science, Uppsala BioCenter, Swedish University of Agricultural Sciences, P. O. Box 7051, 75007 Uppsala, Sweden.
authors.forename: Paresh C
authors.initials: PC
authors.lastname: Dutta
authors.affiliation: Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Jonsson
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, P. O. Box 7080, 75007 Uppsala, Sweden.
authors.forename: Folke
authors.initials: F
authors.lastname: Sitbon
mesh_terms: D000470:Alkaloids / Q000378:metabolism*; D020869:Gene Expression Profiling; D008027:Light; D046228:Microarray Analysis; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects; D013261:Sterols / Q000378:metabolism*
chemical_list: D000470:Alkaloids; D013261:Sterols