title: Conservation and diversification of SCARECROW in maize.
abstract: The SCARECROW (SCR) gene in Arabidopsis is required for asymmetric cell divisions responsible for ground tissue formation in the root and shoot. Previously, we reported that Zea mays SCARECROW (ZmSCR) is the likely maize ortholog of SCR. Here we describe conserved and divergent aspects of ZmSCR. Its ability to complement the Arabidopsis scr mutant phenotype suggests conservation of function, yet its expression pattern during embryogenesis and in the shoot system indicates divergence. ZmSCR expression was detected early during embryogenesis and localized to the endodermal lineage in the root, showing a gradual regionalization of expression. Expression of ZmSCR appeared to be analogous to that of SCR during leaf formation. However, its absence from the maize shoot meristem and its early expression pattern during embryogenesis suggest a diversification of ZmSCR in the patterning processes in maize. To further investigate the evolutionary relationship of SCR and ZmSCR, we performed a phylogenetic analysis using Arabidopsis, rice and maize SCARECROW-LIKE genes (SCLs). We found SCL23 to be the most closely related to SCR in both eudicots and monocots, suggesting that a gene duplication resulting in SCR and SCL23 predates the divergence of dicots and monocots.
authors.affiliation: Department of Molecular Biotechnology, Konkuk University, 143-701 Seoul, Korea. jlim@konkuk.ac.kr
authors.forename: Jun
authors.initials: J
authors.lastname: Lim
authors.forename: Jee W
authors.initials: JW
authors.lastname: Jung
authors.forename: Chae Eun
authors.initials: CE
authors.lastname: Lim
authors.forename: Mi-Hyun
authors.initials: MH
authors.lastname: Lee
authors.forename: Bong Jun
authors.initials: BJ
authors.lastname: Kim
authors.forename: Miran
authors.initials: M
authors.lastname: Kim
authors.forename: Wesley B
authors.initials: WB
authors.lastname: Bruce
authors.forename: Philip N
authors.initials: PN
authors.lastname: Benfey
mesh_terms: D017360:Arabidopsis; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D014644:Genetic Variation; D009154:Mutation; D009928:Organ Specificity; D012275:Oryza; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins