Clonal analysis of the Arabidopsis root confirms that position, not lineage, determines cell fate

 The cellular organization of the Arabidopsis thaliana (L.) Heynh. root meristem suggests that a regular pattern of cell divisions occurs in the root tip. Deviations from this pattern of division might be expected to disrupt the organization of cells and tissues in the root. A clonal analysis of the 3-d-old primary root meristem was carried out to determine if there is variability in division patterns, and if so to discover their effect on cellular organization in the root. Clones induced in the seedling meristem largely confirmed the predicted pattern of cell divisions. However, the cellular initials that normally give rise to the different cell files in the root were shown to exhibit some instability. For example, it was calculated that a lateral root cap/epidermal initial is displaced every 13 d. Furthermore, the existence of large marked clones that included more than two adjacent cell layers suggests that intrusive growth followed by cell division may occur at low frequency, perhaps in response to local cell deaths in the meristem. These findings support the view that even in plant organs with stereotypical cell division patterns, positional information is still the key determinant of cell fate.

Authors and Affiliations

1. Department of Cell Biology, John Innes Centre, Norwich, NR4 7UH, UK, , , , , , GB

   Catherine Kidner, Keith Roberts & Liam Dolan

2. Institute of Molecular Agrobiology, The National University of Singapore, Singapore 117604, , , , , , SG

   Venkatesan Sundaresan

Received: 27 August 1999 / Accepted: 4 December 1999

Reprints and permissions