Email this page

Print this page

Article Addendum

Cortex proliferation: Simple phenotype, complex regulatory mechanisms

Hongchang Cui and Philip N. Benfey

In plants, the cortex is a relatively undifferentiated cell type. Proliferation of cortex tissues initially appeared to be a simple process of repetitive cell division. However, our recent studies showed that in the Arabidopsis root cortex, proliferation involves complex regulatory mechanisms. First, it requires the combined activity of the transcriptional regulators SHORT-ROOT (SHR) and SCARECROW (SCR), but SCR also plays a role in restricting the number of cell divisions. The two opposing activities appear to be mediated by different domains of SCR through physical interaction with distinct partners, and whether SCR behaves as an activator or repressor depends on the relative level of the two protein complexes. We confirmed previous findings that GA plays a major role in cortex proliferation, but also found distinct roles for GA signaling components in this process. We showed that ABA and ethylene also play a role in cortex proliferation, but in an unexpected manner. Finally, we identified an epigenetic component of the regulation, and our data suggested that this is likely the common basis on which various pathways converge. There is evidence that similar mechanisms to those found in Arabidopsis are employed in other plant species.

Addendum to: Cui H, Benfey PN. Interplay between SCARECROW, GA and LIKE HETEROCHROMATIN PROTEIN 1 in ground tissue patterning in the Arabidopsis root. Plant J 2009; PMID: 19228333; DOI: 10.1111/j.1365-313X.2009.03839.x.

Authors

Hongchang Cui

Biology Department, and IGSP Center for Systems Biology; Duke University; Durham, NC USA

Philip N. Benfey Corresponding author: philip.benfey@duke.edu

Biology Department, and IGSP Center for Systems Biology; Duke University; Durham, NC USA