Send to

Choose Destination
Plant Cell. 2007 Nov;19(11):3655-68. Epub 2007 Nov 30.

BIN4, a novel component of the plant DNA topoisomerase VI complex, is required for endoreduplication in Arabidopsis.

Author information

Department of Cell and Developmental Biology, John Ines Centre, Norwich NR4 7UH, United Kingdom.


How plant organs grow to reach their final size is an important but largely unanswered question. Here, we describe an Arabidopsis thaliana mutant, brassinosteroid-insensitive4 (bin4), in which the growth of various organs is dramatically reduced. Small organ size in bin4 is primarily caused by reduced cell expansion associated with defects in increasing ploidy by endoreduplication. Raising nuclear DNA content in bin4 by colchicine-induced polyploidization partially rescues the cell and organ size phenotype, indicating that BIN4 is directly and specifically required for endoreduplication rather than for subsequent cell expansion. BIN4 encodes a plant-specific, DNA binding protein that acts as a component of the plant DNA topoisomerase VI complex. Loss of BIN4 triggers an ATM- and ATR-dependent DNA damage response in postmitotic cells, and this response coincides with the upregulation of the cyclin B1;1 gene in the same cell types, suggesting a functional link between DNA damage response and endocycle control.

[Indexed for MEDLINE]
Free PMC Article

Publication types, MeSH terms, Substances, Grant support

Supplemental Content

Full text links

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