Biphenyl synthase from yeast-extract-treated cell cultures of Sorbus aucuparia
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- Liu, B., Beuerle, T., Klundt, T. et al. Planta (2004) 218: 492. doi:10.1007/s00425-003-1144-y
Biphenyls and dibenzofurans are the phytoalexins of the Maloideae, a subfamily of the economically important Rosaceae. The biphenyl aucuparin accumulated in Sorbus aucuparia L. cell cultures in response to yeast extract treatment. Incubation of cell-free extracts from challenged cell cultures with benzoyl-CoA and malonyl-CoA led to the formation of 3,5-dihydroxybiphenyl. This reaction was catalysed by a novel polyketide synthase, which will be named biphenyl synthase. The most efficient starter substrate for the enzyme was benzoyl-CoA. Relatively high activity was also observed with 2-hydroxybenzoyl-CoA but, instead of the corresponding biphenyl, the derailment product 2-hydroxybenzoyltriacetic acid lactone was formed.
KeywordsAucuparinBenzoic acidBiphenyl synthasePhytoalexinPolyketide synthaseSorbus