Poster: Late and Moved Abstracts

Abs # 988: Molecular analysis of the CRINKLY 4 gene family in Arabidopsis thalian.

Presenter:	Suh, Sang-Gon , sgsuh@yu.ac.kr
Authors	Suh, Sang-Gon  (A) (A)  Xueyuan, Cao  (B) (C)  Kejian, Li  (B) (D)  Tao, Guo  (B) (E)  Philip, Becraft W. (B) (B)
Affiliations:	(A): Yeungnam University, Department of Horticulture (B): Iowa State University, Department of Gentics (C): Iowa State University, Department of Agronomy (D): Iowa State University, Molecular, Cellular and Developmental Biology (E): Iowa State University, Interdepartmental Genetics Program

The maize(Zea mays) CRINKLY4 gene encodes a serine/threonine receptor-like kinase that controls an array of developmental processes in the plant and endosperm. The Arabidopsis genome encodes an ortholog of CR4, ACR4, and four CRINKLY4-RELATED(CRR) proteins:AtCRR1,2,3 and AtCRK1. The available genome sequence of rice(Oryza sativa) encodes a CR4 ortholog, OsCR4, and four CRR proteins: OsCRR1,2,3 and 4, not necessarily orthologous to the Arabidopsis CRRs. A phylogenetic study showed that AtCRR1 and 2 form a clade closest to the CR4 group while all the other CRRs form a separate cluster. The five Arabidopsis genes are differentially expressed in various tissues. An ACR4 promoter::GUS fusion is expressed primarily in developing tissues of the shoot. The ACR4 cytoplasmic domain fuctions in vitro as a serine/threonine kinase, while the AtCRR1 and 2 kinases are not active. The ability of ACR4 to phosphorylate AtCRR2 suggests that they might fuction in the same signal transduction pathway. T-DNA insertion were obtained in ACR4, AtCRR1,2,3 and AtCRK1. Mutations in acr4 show a phenotype restricted to the integuments and sees coat, suggesting that Arabidopsi might contatin a redundant function. The lack of obvious mutant phenotypes in the crr mutants indicates they do not encode the redundant function.