Mutants of Arabidopsis thaliana with altered responses to auxins and gravity

Biochem Genet. 1980 Dec;18(11-12):1041-53. doi: 10.1007/BF00484337.


Auxin-resistant mutants of Arabidopsis have been induced and isolated by screening for survivors on a medium containing the herbicide 2,4-D. Thirty independently arisen mutants have been isolated in this way and one of them, P 83, has been investigated in detail. When wild type and P 83 are compared in concentration/response curves, where the response is the inhibition of root growth, the ED50 values of the auxins, 2,4-D and IAA, are 14-fold higher for the mutant. The mutant also responds differently to gravity: its roots do not show positive geotropism, but tend to grow with a clockwise curvature on agar surfaces. The seedling roots of the mutant also grow more rapidly than those of the wild type in the absence of 2,4-D, following faster germination. The F1 between P 83 and wild type is similar to the latter, but has a slightly increased resistance to 2,4-D. Results obtained from the F2, F3 and backcross generations suggest monofactorial inheritance. Most of the other 29 mutants have the P 83 phenotype, but at least five are different. Four have lower levels of resistance to 2,4-D and P 83, and their roots appear to respond normally to gravity. One mutant has an abnormal georesponse and a much higher level of resistance to 2,4-D than P 83.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dose-Response Relationship, Drug
  • Gravitation
  • Indoleacetic Acids / pharmacology*
  • Mutation*
  • Phenotype
  • Plant Development
  • Plant Growth Regulators / pharmacology*
  • Plants / genetics*


  • Indoleacetic Acids
  • Plant Growth Regulators