Isolation and Functional Analysis of SpWOX13 from Stipa purpurea

Abstract

Members of the WUSCHEL-related homeobox (WOX) gene family encode plant-specific transcription factors that play key roles in controlling gene expression at all stages of plant development. In the present study, we isolated and characterized SpWOX13 (GenBank accession no. KJ713172), a member of the WOX gene family, from Stipa purpurea. Sequence and phylogenetic analyses showed that SpWOX13 belongs to an ancient clade of WOX genes. A subcellular localization analysis indicated that SpWOX13 localizes in the nucleus. The transcript levels of SpWOX13 were higher in young leaves and the vegetative apex than in other tissues of S. purpurea. Ectopic expression of SpWOX13 in Arabidopsis resulted in late flowering plants as these showed more rosette leaves. Histological analyses of the transgenic plants showed aberrant arrangements in the tunica cell layers of the shoot apical meristem. Scanning electron microscopy analyses revealed that the leaf pavement cells were larger in SpWOX13-overexpressing transgenic plants than in wild type. Our results suggest that SpWOX13 is involved in delaying and/or inhibiting cell differentiation.