Cytokinins act directly on lateral root founder cells to inhibit root initiation

L. Laplaze, E. Benkova, I. Casimiro, L. Maes, S. Vanneste, R. Swarup, D. Weijers, V. Calvo, B. Parizot, M.B. Herrera-Rodriguez, R. Offringa, N. Graham, P. Doumas, J. Friml, D. Bogusz, T. Beeckman, M. Bennett

Research output: Contribution to journalArticleAcademicpeer-review

350 Citations (Scopus)

Abstract

In Arabidopsis thaliana, lateral roots are formed from root pericycle cells adjacent to the xylem poles. Lateral root development is regulated antagonistically by the plant hormones auxin and cytokinin. While a great deal is known about how auxin promotes lateral root development, the mechanism of cytokinin repression is still unclear. Elevating cytokinin levels was observed to disrupt lateral root initiation and the regular pattern of divisions that characterizes lateral root development in Arabidopsis. To identify the stage of lateral root development that is sensitive to cytokinins, we targeted the expression of the Agrobacterium tumefaciens cytokinin biosynthesis enzyme isopentenyltransferase to either xylem-pole pericycle cells or young lateral root primordia using GAL4-GFP enhancer trap lines. Transactivation experiments revealed that xylem-pole pericycle cells are sensitive to cytokinins, whereas young lateral root primordia are not. This effect is physiologically significant because transactivation of the Arabidopsis cytokinin degrading enzyme cytokinin oxidase 1 in lateral root founder cells results in increased lateral root formation. We observed that cytokinins perturb the expression of PIN genes in lateral root founder cells and prevent the formation of an auxin gradient that is required to pattern lateral root primordia.
Original languageEnglish
Pages (from-to)3889-3900
JournalThe Plant Cell
Volume19
Issue number12
DOIs
Publication statusPublished - 2007

Keywords

  • arabidopsis-thaliana
  • response regulators
  • tobacco plants
  • pea roots
  • auxin
  • shoot
  • gene
  • expression
  • pericycle
  • meristem

Fingerprint Dive into the research topics of 'Cytokinins act directly on lateral root founder cells to inhibit root initiation'. Together they form a unique fingerprint.

  • Cite this

    Laplaze, L., Benkova, E., Casimiro, I., Maes, L., Vanneste, S., Swarup, R., Weijers, D., Calvo, V., Parizot, B., Herrera-Rodriguez, M. B., Offringa, R., Graham, N., Doumas, P., Friml, J., Bogusz, D., Beeckman, T., & Bennett, M. (2007). Cytokinins act directly on lateral root founder cells to inhibit root initiation. The Plant Cell, 19(12), 3889-3900. https://doi.org/10.1105/tpc.107.055863