Skip to main content
PMC home page
Genetics logoLink to Genetics
. 1995 May;140(1):303–313. doi: 10.1093/genetics/140.1.303

5-Fluoroindole Resistance Identifies Tryptophan Synthase Beta Subunit Mutants in Arabidopsis Thaliana

A J Barczak 1, J Zhao 1, K D Pruitt 1, R L Last 1
PMCID: PMC1206557  PMID: 7635295

Abstract

A study of the biochemical genetics of the Arabidopsis thaliana tryptophan synthase beta subunit was initiated by characterization of mutants resistant to the inhibitor 5-fluoroindole. Thirteen recessive mutations were recovered that are allelic to trp2-1, a mutation in the more highly expressed of duplicate tryptophan synthase beta subunit genes (TSB1). Ten of these mutations (trp2-2 through trp2-11) cause a tryptophan requirement (auxotrophs), whereas three (trp2-100 through trp2-102) remain tryptophan prototrophs. The mutations cause a variety of changes in tryptophan synthase beta expression. For example, two mutations (trp2-5 and trp2-8) cause dramatically reduced accumulation of TSB mRNA and immunologically detectable protein, whereas trp2-10 is associated with increased mRNA and protein. A correlation exists between the quantity of mutant beta and wild-type alpha subunit levels in the trp2 mutant plants, suggesting that the synthesis of these proteins is coordinated or that the quantity or structure of the beta subunit influences the stability of the alpha protein. The level of immunologically detectable anthranilate synthase alpha subunit protein is increased in the trp2 mutants, suggesting the possibility of regulation of anthranilate synthase levels in response to tryptophan limitation.

Full Text

The Full Text of this article is available as a PDF (1.8 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Berlyn M. B., Last R. L., Fink G. R. A gene encoding the tryptophan synthase beta subunit of Arabidopsis thaliana. Proc Natl Acad Sci U S A. 1989 Jun;86(12):4604–4608. doi: 10.1073/pnas.86.12.4604. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Burns D. M., Yanofsky C. Nucleotide sequence of the Neurospora crassa trp-3 gene encoding tryptophan synthetase and comparison of the trp-3 polypeptide with its homologs in Saccharomyces cerevisiae and Escherichia coli. J Biol Chem. 1989 Mar 5;264(7):3840–3848. [PubMed] [Google Scholar]
  3. Church G. M., Gilbert W. Genomic sequencing. Proc Natl Acad Sci U S A. 1984 Apr;81(7):1991–1995. doi: 10.1073/pnas.81.7.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Delmer D. P., Mills S. Tryptophan synthase from Nicotiana tabacum. Biochim Biophys Acta. 1968 Oct 8;167(2):431–443. doi: 10.1016/0005-2744(68)90223-4. [DOI] [PubMed] [Google Scholar]
  5. Haughn G. W., Davin L., Giblin M., Underhill E. W. Biochemical Genetics of Plant Secondary Metabolites in Arabidopsis thaliana: The Glucosinolates. Plant Physiol. 1991 Sep;97(1):217–226. doi: 10.1104/pp.97.1.217. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Higuchi R. G., Ochman H. Production of single-stranded DNA templates by exonuclease digestion following the polymerase chain reaction. Nucleic Acids Res. 1989 Jul 25;17(14):5865–5865. doi: 10.1093/nar/17.14.5865. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hyde C. C., Ahmed S. A., Padlan E. A., Miles E. W., Davies D. R. Three-dimensional structure of the tryptophan synthase alpha 2 beta 2 multienzyme complex from Salmonella typhimurium. J Biol Chem. 1988 Nov 25;263(33):17857–17871. [PubMed] [Google Scholar]
  8. Jofuku K. D., Schipper R. D., Goldberg R. B. A frameshift mutation prevents Kunitz trypsin inhibitor mRNA accumulation in soybean embryos. Plant Cell. 1989 Apr;1(4):427–435. doi: 10.1105/tpc.1.4.427. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Last R. L., Fink G. R. Tryptophan-Requiring Mutants of the Plant Arabidopsis thaliana. Science. 1988 Apr 15;240(4850):305–310. doi: 10.1126/science.240.4850.305. [DOI] [PubMed] [Google Scholar]
  10. Miles E. W. Structural basis for catalysis by tryptophan synthase. Adv Enzymol Relat Areas Mol Biol. 1991;64:93–172. doi: 10.1002/9780470123102.ch3. [DOI] [PubMed] [Google Scholar]
  11. Niyogi K. K., Fink G. R. Two anthranilate synthase genes in Arabidopsis: defense-related regulation of the tryptophan pathway. Plant Cell. 1992 Jun;4(6):721–733. doi: 10.1105/tpc.4.6.721. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Niyogi K. K., Last R. L., Fink G. R., Keith B. Suppressors of trp1 fluorescence identify a new arabidopsis gene, TRP4, encoding the anthranilate synthase beta subunit. Plant Cell. 1993 Sep;5(9):1011–1027. doi: 10.1105/tpc.5.9.1011. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Normanly J., Cohen J. D., Fink G. R. Arabidopsis thaliana auxotrophs reveal a tryptophan-independent biosynthetic pathway for indole-3-acetic acid. Proc Natl Acad Sci U S A. 1993 Nov 1;90(21):10355–10359. doi: 10.1073/pnas.90.21.10355. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Pruitt K. D., Hanson M. R. Transcription of the Petunia mitochondrial CMS-associated Pcf locus in male sterile and fertility-restored lines. Mol Gen Genet. 1991 Jul;227(3):348–355. doi: 10.1007/BF00273922. [DOI] [PubMed] [Google Scholar]
  15. Rose A. B., Casselman A. L., Last R. L. A Phosphoribosylanthranilate Transferase Gene Is Defective in Blue Fluorescent Arabidopsis thaliana Tryptophan Mutants. Plant Physiol. 1992 Oct;100(2):582–592. doi: 10.1104/pp.100.2.582. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Shirley B. W., Hanley S., Goodman H. M. Effects of ionizing radiation on a plant genome: analysis of two Arabidopsis transparent testa mutations. Plant Cell. 1992 Mar;4(3):333–347. doi: 10.1105/tpc.4.3.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Sullivan M. L., Green P. J. Post-transcriptional regulation of nuclear-encoded genes in higher plants: the roles of mRNA stability and translation. Plant Mol Biol. 1993 Dec;23(6):1091–1104. doi: 10.1007/BF00042344. [DOI] [PubMed] [Google Scholar]
  18. Tsay Y. F., Schroeder J. I., Feldmann K. A., Crawford N. M. The herbicide sensitivity gene CHL1 of Arabidopsis encodes a nitrate-inducible nitrate transporter. Cell. 1993 Mar 12;72(5):705–713. doi: 10.1016/0092-8674(93)90399-b. [DOI] [PubMed] [Google Scholar]
  19. Voelker T. A., Moreno J., Chrispeels M. J. Expression analysis of a pseudogene in transgenic tobacco: a frameshift mutation prevents mRNA accumulation. Plant Cell. 1990 Mar;2(3):255–261. doi: 10.1105/tpc.2.3.255. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Wilkinson J. Q., Crawford N. M. Identification of the Arabidopsis CHL3 gene as the nitrate reductase structural gene NIA2. Plant Cell. 1991 May;3(5):461–471. doi: 10.1105/tpc.3.5.461. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Wright A. D., Moehlenkamp C. A., Perrot G. H., Neuffer M. G., Cone K. C. The maize auxotrophic mutant orange pericarp is defective in duplicate genes for tryptophan synthase beta. Plant Cell. 1992 Jun;4(6):711–719. doi: 10.1105/tpc.4.6.711. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Zalkin H., Yanofsky C. Yeast gene TRP5: structure, function, regulation. J Biol Chem. 1982 Feb 10;257(3):1491–1500. [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES