title: Genomic clustering of cyanogenic glucoside biosynthetic genes aids their identification in Lotus japonicus and suggests the repeated evolution of this chemical defence pathway.
abstract: Cyanogenic glucosides are amino acid-derived defence compounds found in a large number of vascular plants. Their hydrolysis by specific β-glucosidases following tissue damage results in the release of hydrogen cyanide. The cyanogenesis deficient1 (cyd1) mutant of Lotus japonicus carries a partial deletion of the CYP79D3 gene, which encodes a cytochrome P450 enzyme that is responsible for the first step in cyanogenic glucoside biosynthesis. The genomic region surrounding CYP79D3 contains genes encoding the CYP736A2 protein and the UDP-glycosyltransferase UGT85K3. In combination with CYP79D3, these genes encode the enzymes that constitute the entire pathway for cyanogenic glucoside biosynthesis. The biosynthetic genes for cyanogenic glucoside biosynthesis are also co-localized in cassava (Manihot esculenta) and sorghum (Sorghum bicolor), but the three gene clusters show no other similarities. Although the individual enzymes encoded by the biosynthetic genes in these three plant species are related, they are not necessarily orthologous. The independent evolution of cyanogenic glucoside biosynthesis in several higher plant lineages by the repeated recruitment of members from similar gene families, such as the CYP79s, is a likely scenario.
authors.affiliation: Plant Biochemistry Laboratory, Department of Plant Biology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark.
authors.forename: Adam M
authors.initials: AM
authors.lastname: Takos
authors.forename: Camilla
authors.initials: C
authors.lastname: Knudsen
authors.forename: Daniela
authors.initials: D
authors.lastname: Lai
authors.forename: Rubini
authors.initials: R
authors.lastname: Kannangara
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Mikkelsen
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Motawia
authors.forename: Carl E
authors.initials: CE
authors.lastname: Olsen
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Kirsten
authors.initials: K
authors.lastname: Jørgensen
authors.forename: Birger L
authors.initials: BL
authors.lastname: Møller
authors.forename: Fred
authors.initials: F
authors.lastname: Rook
mesh_terms: D005075:Biological Evolution; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics; D005960:Glucosides / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D006027:Glycosides / Q000737:chemistry / Q000378:metabolism; D006856:Hydrogen Cyanide / Q000378:metabolism; D000070116:Lotus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D002365:Manihot / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D015394:Molecular Structure; D005810:Multigene Family; D009154:Mutation; D009570:Nitriles / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D045868:Sorghum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D005960:Glucosides; D006027:Glycosides; D009570:Nitriles; D010940:Plant Proteins; D018749:RNA, Plant; C096498:rhodiocyanoside A; C108905:rhodiocyanoside D; D006856:Hydrogen Cyanide; D003577:Cytochrome P-450 Enzyme System; C586806:cytochrome P-450 736A2, Lotus japonicus; C492216:cytochrome P-450 79D3, Lotus japonicus; D005964:Glucosyltransferases; C586808:UGT85K3 protein, Lotus japonicus