@article{melanson_chilton_mastersmoore_chilton_1997, title={A deletion in an indole synthase gene is responsible for the DIMBOA-deficient phenotype of bxbx maize}, volume={94}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.94.24.13345}, abstractNote={The biosynthesis of DIMBOA, a pesticidal secondary metabolite of maize, branches off the tryptophan pathway. We have previously demonstrated that indole is the last intermediate common to both the tryptophan and hydroxamic acid pathways. The earliest discovered mutant in the DIMBOA pathway,bxbx(benzoxazineless), is deficient in the production of DIMBOA and related compounds. This paper presents evidence that a gene identified by Kramer and Koziel [Kramer, V. C. & Koziel, M. G. (1995)Plant Mol. Biol.27, 1183–1188] as maize tryptophan synthase α (TSA) is the site of the genetic lesion in the DIMBOA-deficient mutant maize linebxbx. We demonstrate that theTSAgene has sustained a 924-bp deletion inbxbxcompared with its counterpart in wild-type maize. We report that theTSAgene maps to the same location as thebxbxmutation, on the short arm of chromosome 4. We present evidence that the very early and very high level of expression ofTSAcorresponds to the timing and level of DIMBOA biosynthesis but is strikingly different from the expression of the maize tryptophan synthase β (TSB) genes. We show that feeding indole tobxbxseedlings restores their ability to synthesize DIMBOA. We conclude that the maize enzyme initially named tryptophan synthase α in fact is a DIMBOA biosynthetic enzyme, and we propose that it be renamed indole synthase. This work confirms and enlarges upon the findings of Freyet al.[Frey, M. Chomet, P., Glawischniq, E., Stettner, C., Grün, S., Winklmair, A., Eisenreich, W., Bacher, A., Meeley, R. B., Briggs, S. P., Simcox, K. & Gierl, A. (1997)Science277, 696–699], which appeared while the present paper was in review.}, number={24}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Melanson, D and Chilton, MD and MastersMoore, D and Chilton, WS}, year={1997}, month={Nov}, pages={13345–13350} }