Current address: Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
Arabidopsis ALF4 encodes a nuclear-localized protein required for lateral root formation
Article first published online: 11 DEC 2003
The Plant Journal
Volume 37, Issue 3, pages 340–353, February 2004
How to Cite
DiDonato, R. J., Arbuckle, E., Buker, S., Sheets, J., Tobar, J., Totong, R., Grisafi, P., Fink, G. R. and Celenza, J. L. (2004), Arabidopsis ALF4 encodes a nuclear-localized protein required for lateral root formation. The Plant Journal, 37: 340–353. doi: 10.1046/j.1365-313X.2003.01964.x
- Issue published online: 9 JAN 2004
- Article first published online: 11 DEC 2003
- Received 13 July 2003; revised 30 September 2003; accepted 20 October 2003.
- lateral root formation;
- developmental plasticity;
- cell cycle;
Lateral root formation, the primary way plants increase their root mass, displays developmental plasticity in response to environmental changes. The aberrant lateral root formation (alf)4-1 mutation blocks the initiation of lateral roots, thus greatly altering root system architecture. We have positionally cloned the ALF4 gene and have further characterized its phenotype. The encoded ALF4 protein is conserved among plants and has no similarities to proteins from other kingdoms. The gene is present in a single copy in Arabidopsis. Using translational reporters for ALF4 gene expression, we have determined that the ALF4 protein is nuclear localized and that the gene is expressed in most plant tissues; however, ALF4 expression and ALF4's subcellular location are not regulated by auxin. These findings taken together with further genetic and phenotypic characterization of the alf4-1 mutant suggest that ALF4 functions independent from auxin signaling and instead functions in maintaining the pericycle in the mitotically competent state needed for lateral root formation. Our results provide genetic evidence that the pericycle shares properties with meristems and that this tissue plays a central role in creating the developmental plasticity needed for root system development.