title: Ectopic expression of foxtail millet zip-like gene, SiPf40, in transgenic rice plants causes a pleiotropic phenotype affecting tillering, vascular distribution and root development.
abstract: Plant architecture determines grain production in rice (Oryza sativa) and is affected by important agronomic traits such as tillering, plant height, and panicle morphology. Many key genes involved in controlling the initiation and outgrowth of axillary buds, the elongation of stems, and the architecture of inflorescences have been isolated and analyzed. Previous studies have shown that SiPf40, which was identified from a foxtail millet (Setaria italica) immature seed cDNA library, causes extra branches and tillers in SiPf40-transgenic tobacco and foxtail millet, respectively. To reconfirm its function, we generated transgenic rice plants overexpressing SiPf40 under the control of the ubiquitin promoter. SiPf40-overexpressing transgenic plants have a greater tillering number and a wider tiller angle than wild-type plants. Their root architecture is modified by the promotion of lateral root development, and the distribution of xylem and phloem in the vascular bundle is affected. Analysis of hormone levels showed that the ratios of indole-3-acetic acid/zeatin (IAA/ZR) and IAA/gibberellic acid (IAA/GA) decreased in SiPf40-transgenic plants compared with wild-type plants. These findings strongly suggest that SiPf40 plays an important role in plant architecture.
authors.affiliation: State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Luan
authors.forename: Baosheng
authors.initials: B
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.forename: Guangming
authors.initials: G
authors.lastname: Ao
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D019295:Computational Biology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005875:Gibberellins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D010641:Phenotype; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D032983:Setaria Plant / Q000235:genetics* / Q000378:metabolism
chemical_list: D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C030737:indoleacetic acid; C007842:gibberellic acid