A novel pathway for sesquiterpene biosynthesis from Z,Z-farnesyl pyrophosphate in the wild tomato Solanum habrochaites.
In the wild tomato Solanum habrochaites, the Sst2 locus on chromosome 8 is responsible for the biosynthesis of several class II sesquiterpene olefins by glandular trichomes. Analysis of a trichome-specific EST collection from S. habrochaites revealed two candidate genes for the synthesis of Sst2-associated sesquiterpenes. zFPS encodes a protein with homology to Z-isoprenyl pyrophosphate synthases and SBS (for Santalene and Bergamotene Synthase) encodes a terpene synthase with homology to kaurene synthases. Both genes were found to cosegregate with the Sst2 locus. Recombinant zFPS protein catalyzed the synthesis of Z,Z-FPP from isopentenylpyrophosphate (IPP) and dimethylallylpyrophosphate (DMAPP), while coincubation of zFPS and SBS with the same substrates yielded a mixture of olefins identical to the Sst2-associated sesquiterpenes, including (+)-alpha-santalene, (+)-endo-beta-bergamotene, and (-)-endo-alpha-bergamotene. In addition, headspace analysis of tobacco (Nicotiana sylvestris) plants expressing zFPS and SBS in glandular trichomes afforded the same mix of sesquiterpenes. Each of these proteins contains a putative plastid targeting sequence that mediates transport of a fused green fluorescent protein to the chloroplasts, suggesting that the biosynthesis of these sesquiterpenes uses IPP and DMAPP from the plastidic DXP pathway. These results provide novel insights into sesquiterpene biosynthesis and have general implications concerning sesquiterpene engineering in plants.
Sallaud
Christophe
C
Librophyt, Centre de Cadarache, 13115 St. Paul-Lez-Durance, France.
Rontein
Denis
D
Onillon
Sandrine
S
Jabès
Françoise
F
Duffé
Philippe
P
Giacalone
Cécile
C
Thoraval
Samuel
S
Escoffier
Camille
C
Herbette
Gaëtan
G
Leonhardt
Nathalie
N
Causse
Mathilde
M
Tissier
Alain
A
D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D020224:Expressed Sequence Tags; D017343:Genes, Plant; D051228:Geranyltranstransferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000378:metabolism; D011106:Polyisoprenyl Phosphates / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012717:Sesquiterpenes / Q000378:metabolism*; D032322:Solanum / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000378:metabolism
D018744:DNA, Plant; D010940:Plant Proteins; D011106:Polyisoprenyl Phosphates; D011994:Recombinant Proteins; D012717:Sesquiterpenes; C004808:farnesyl pyrophosphate; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase; D051228:Geranyltranstransferase