Send to

Choose Destination
See comment in PubMed Commons below
Plant Physiol. 1995 Jan;107(1):233-243.

STUNTED PLANT 1, A Gene Required for Expansion in Rapidly Elongating but Not in Dividing Cells and Mediating Root Growth Responses to Applied Cytokinin.

Author information

Plant Cell Biology Group, Research School of Biological Sciences, Australian National University Canberra, Australian Capital Territory 2601, Australia (T.I.B., A.C., R.E.W.).


To understand the control of spatial patterns of expansion, we have studied root growth in wild type and in the stunted plant 1 mutant, stp1, of Arabidopsis thaliana. We measured profiles of cell length and calculated the distribution of elongation rate. Slow growth of stp1 results both from a failure of dividing cell number to increase and from low elongation rates in the zone of rapid expansion. However, elongation of dividing cells was not greatly affected, and stp1 and wild-type callus grew at identical rates. Thus, rapid cellular expansion differs in mechanism from expansion in dividing cells and is facilitated by the STP1 gene. Additionally, there was no difference between stp1 and wild-type roots for elongation in response to abscisic acid, auxin, ethylene, or gibberellic acid or for radial expansion in response to ethylene; however, stp1 responded to cytokinin much less than wild type. In contrast, both genotypes responded comparably to hormones when explants were cultured; in particular, there was no difference between genotypes in shoot regeneration in response to cytokinin. Thus, effects on root expansion mediated by cytokinin, but not effects mediated by other hormones or effects on other cytokinin-mediated responses, require the STP1 locus.

PubMed Commons home

PubMed Commons


    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center