Poster: Vegetative development

Abs # 320: T-DNA insertional knockouts of Arabidopsis Cam sequences

Presenter:	Zielinski, Ray , zielinsk@life.uiuc.edu
Authors	Zielinski, Ray  (A)   Damlich, Jen  (A)   Schlicksup, Kevin  (A)   Kocher, Sarah  (A)   Kays, Julia  (B)
Affiliations:	(A): University Of Illinois (B): University of Texas-Austin
Web Site:	http://www.life.uiuc.edu/zielinski/

The Arabidopsis genome encodes seven calmodulin (Cam)genes and numerous Cam-like genes. Using the Salk T-DNA insertional knockout collection, we have identified and characterized knockouts in the coding or promoter regions of five of the seven Cam genes (AtCam2, 3, 4, 5 and 7) and in two Cam-like genes (AtCam8 and 9). Homozygous knockout lines of AtCam2, 3 and 5, which encode identical protein products, are not lethal but result in plants with reduced growth to dwarfed phenotypes. Differences in apparent tolerance to water stress and fertility are also observed in these lines. Our results suggest that these highly conserved Cam genes do not serve completely redundant functions. AtCam8 and 9 encode Ca²⁺-binding proteins that share 73 and 49% amino acid sequence identity with the Cam proteins encoded by AtCam2, 3 and 5, respectively. Knockouts of these genes display an enlarged rosette and leaf morphology compared with WT controls. Supported by NSF MCB-0235544.