title: The over-expression of an Arabidopsis B3 transcription factor, ABS2/NGAL1, leads to the loss of flower petals.
abstract: Transcriptional regulations are involved in many aspects of plant development and are mainly achieved through the actions of transcription factors (TF). To investigate the mechanisms of plant development, we carried out genetic screens for mutants with abnormal shoot development. Taking an activation tagging approach, we isolated a gain-of-function mutant abs2-1D (abnormal shoot 2-1D). abs2-1D showed pleiotropic growth defects at both the vegetative and reproductive developmental stages. We cloned ABS2 and it encodes a RAV sub-family of plant B3 type of transcriptional factors. Phylogenetic analysis showed that ABS2 was closely related to NGATHA (NGA) genes that are involved in flower development and was previously named NGATHA-Like 1 (NGAL1). NGAL1 was expressed mainly in the root and the filament of the stamen in flower tissues and sub-cellular localization assay revealed that NGAL1 accumulated in the nucleus. Interestingly, over-expression of NGAL1 driven by the constitutive 35S promoter led to transgenic plants with conspicuous flower defects, particularly a loss-of-petal phenotype. A loss-of-function ngal1-1 mutant did not show obvious phenotype, suggesting the existence of redundant activities and also the utility of gain-of-function genetic screens. Our results show that the over-expression of NGAL1 is capable of altering flower petal development, as well as shoot development.
authors.affiliation: College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Jingxia
authors.initials: J
authors.lastname: Shao
authors.forename: Xiayan
authors.initials: X
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Gaisheng
authors.initials: G
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development*; D030821:Plants, Genetically Modified; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C581295:ABS2 protein, Arabidopsis; D029681:Arabidopsis Proteins; C543686:NGA1 protein, Arabidopsis thaliana; D014157:Transcription Factors