title: Biosynthesis of antinutritional alkaloids in solanaceous crops is mediated by clustered genes.
abstract: Steroidal glycoalkaloids (SGAs) such as α-solanine found in solanaceous food plants--as, for example, potato--are antinutritional factors for humans. Comparative coexpression analysis between tomato and potato coupled with chemical profiling revealed an array of 10 genes that partake in SGA biosynthesis. We discovered that six of them exist as a cluster on chromosome 7, whereas an additional two are adjacent in a duplicated genomic region on chromosome 12. Following systematic functional analysis, we suggest a revised SGA biosynthetic pathway starting from cholesterol up to the tetrasaccharide moiety linked to the tomato SGA aglycone. Silencing GLYCOALKALOID METABOLISM 4 prevented accumulation of SGAs in potato tubers and tomato fruit. This may provide a means for removal of unsafe, antinutritional substances present in these widely used food crops.
authors.affiliation: Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Itkin
authors.forename: U
authors.initials: U
authors.lastname: Heinig
authors.forename: O
authors.initials: O
authors.lastname: Tzfadia
authors.forename: A J
authors.initials: AJ
authors.lastname: Bhide
authors.forename: B
authors.initials: B
authors.lastname: Shinde
authors.forename: P D
authors.initials: PD
authors.lastname: Cardenas
authors.forename: S E
authors.initials: SE
authors.lastname: Bocobza
authors.forename: T
authors.initials: T
authors.lastname: Unger
authors.forename: S
authors.initials: S
authors.lastname: Malitsky
authors.forename: R
authors.initials: R
authors.lastname: Finkers
authors.forename: Y
authors.initials: Y
authors.lastname: Tikunov
authors.forename: A
authors.initials: A
authors.lastname: Bovy
authors.forename: Y
authors.initials: Y
authors.lastname: Chikate
authors.forename: P
authors.initials: P
authors.lastname: Singh
authors.forename: I
authors.initials: I
authors.lastname: Rogachev
authors.forename: J
authors.initials: J
authors.lastname: Beekwilder
authors.forename: A P
authors.initials: AP
authors.lastname: Giri
authors.forename: A
authors.initials: A
authors.lastname: Aharoni
mesh_terms: D018556:Crops, Agricultural / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000235:genetics*; D005810:Multigene Family; D009753:Nutritive Value / Q000235:genetics*; D012991:Solanaceous Alkaloids / Q000096:biosynthesis* / Q000235:genetics* / Q000633:toxicity; D011198:Solanum tuberosum / Q000235:genetics*
chemical_list: D012991:Solanaceous Alkaloids