Poster: Reproductive Development

Abs # 472: Regulation of KNAT1 by two Arabidopsis zinc finger proteins

Presenter:	Krizek, Beth A, krizek@sc.edu
Authors	Krizek, Beth A (A)   Warren, Daniel  (A)   Lewis, Mike  (A)   Connolly, Erin  (A)
Affiliations:	(A): University of South Carolina

All aboveground organs of a plant arise from cells in the shoot apical meristem. The mechanisms by which cells in a meristem are partitioned between those that will remain meristematic and those that will become part of determinate organs are poorly understood. Class I KNOX genes appear to be important components in defining these different cell populations. We have identified two new potential regulators of the class I KNOX protein, KNAT1. Overexpression of either of two zinc finger genes, ZAT7 and ZAT12, in Arabidopsis thaliana results in plants with curled leaves, downward-pointing siliques, short petioles, and short internodes. These plants closely resemble the brevipedicellus (bp) mutant that has a disruption in KNAT1. ZAT7 and ZAT12 are members of a family of zinc finger proteins that contain two or three zinc fingers, a hydrophobic motif, and a transcriptional repression domain. The phenotype of 35S::ZAT7 plants does not appear to result from transcriptional repression of KNAT1 as a KNAT1::GUS reporter gene is expressed at high levels in these plants. We are currently investigating the roles of ZAT7 and ZAT12 during development by characterizing the expression pattern of these genes and obtaining loss of function alleles. These studies should help to illuminate the mechanism by which ZAT7 and ZAT12 regulate KNAT1 activity.