Biochemical genetics of glucosinolate modification in Arabidopsis and Brassica

Fine mapping of the glucosinolate biosynthesis gene OHP, which regulates the conversion of 3-methylsulphinylpropyl to 3-hydroxypropyl glucosinolate, in an Arabidopsis thaliana Columbia × Landsberg erecta RI line population positioned the gene within 54 kb of DNA on chromosome IV. Sequence data identified a family of genes encoding 2-oxoglutarate-dependent dioxygenases in this region. A probe based on these genes co-segregated with ALK in Brassica oleracea,a gene regulating the synthesis of alkenyl glucosinolates. The reactions catalysed by the OHP and ALK enzymes utilise similar substrates and may have a common mechanism. Thus, these dioxygenases are prime candidates for controlling the side chain modification of glucosinolates.

Authors and Affiliations

1. John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH Fax: +44(0)1603 259882 e-mail: Richard.Mithen@bbsrc.ac.uk, , , , , , GB

   C. Hall, A. Prescott & R. Mithen

2. Max Planck Institute of Chemical Ecology, Tatzendpromenade 1a, 07745 Jena, Germany, , , , , , DE

   D. McCallum

Received: 12 May 2000 / Accepted: 29 May 2000

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