Auxin polar transport in Arabidopsis under simulated microgravity conditions--relevance to growth and development

Adv Space Res. 1999;23(12):2033-6. doi: 10.1016/s0273-1177(99)00344-0.

Abstract

Activity of auxin polar transport in inflorescence axes of Arabidopsis thaliana grown under simulated microgravity conditions was studied in relation to the growth and development. Seeds were germinated and allowed to grow on an agar medium in test tubes on a horizontal clinostat. Horizontal clinostat rotation substantially reduced the growth of inflorescence axes and the productivity of seeds of Arabidopsis thaliana (ecotypes Landsberg erecta and Columbia), although it little affected seed germination, development of rosette leaves and flowering. The activity of auxin polar transport in inflorescence axes decreased when Arabidopsis plants were grown on a horizontal clinostat from germination stage, being ca. 60% of 1 g control. On the other hand, the auxin polar transport in inflorescence axes of Arabidopsis grown in 1 g conditions was not affected when the segments were exposed to various gravistimuli, including 3-dimensional clinorotation, during transport experiments. Pin-formed mutant of Arabidopsis, having a unique structure of the inflorescence axis with no flower and extremely low levels of the activity of auxin polar transport in inflorescence axes and endogenous auxin, did not continue its vegetative growth under clinostat rotation. These facts suggest that the development of the system of auxin polar transport in Arabidopsis is affected by microgravity, resulting in the inhibition of growth and development, especially during reproductive growth.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism*
  • Biological Transport / physiology
  • Germination / physiology
  • Gravitation
  • Indoleacetic Acids / metabolism
  • Indoleacetic Acids / pharmacokinetics*
  • Mutation
  • Plant Growth Regulators / metabolism
  • Plant Growth Regulators / pharmacokinetics*
  • Plant Leaves / genetics
  • Plant Leaves / growth & development
  • Plant Leaves / metabolism
  • Rotation
  • Seeds / genetics
  • Seeds / growth & development
  • Seeds / metabolism
  • Weightlessness Simulation*

Substances

  • Indoleacetic Acids
  • Plant Growth Regulators
  • indoleacetic acid