title: Functional characterization of the Arabidopsis eukaryotic translation initiation factor 5A-2 that plays a crucial role in plant growth and development by regulating cell division, cell growth, and cell death.
abstract: The eukaryotic translation initiation factor 5A (eIF-5A) is a highly conserved protein found in all eukaryotic organisms. Although originally identified as a translation initiation factor, recent studies in mammalian and yeast (Saccharomyces cerevisiae) cells suggest that eIF-5A is mainly involved in RNA metabolism and trafficking, thereby regulating cell proliferation, cell growth, and programmed cell death. In higher plants, the physiological function of eIF-5A remains largely unknown. Here, we report the identification and characterization of an Arabidopsis (Arabidopsis thaliana) mutant fumonisin B(1)-resistant12 (fbr12). The fbr12 mutant shows an antiapoptotic phenotype and has reduced dark-induced leaf senescence. Moreover, fbr12 displays severe defects in plant growth and development. The fbr12 mutant plant is extreme dwarf with substantially reduced size and number of all adult organs. During reproductive development, fbr12 causes abnormal development of floral organs and defective sporogenesis, leading to the abortion of both female and male germline cells. Microscopic studies revealed that these developmental defects are associated with abnormal cell division and cell growth. Genetic and molecular analyses indicated that FBR12 encodes a putative eIF-5A-2 protein. When expressed in a yeast mutant strain carrying a mutation in the eIF-5A gene, FBR12 cDNA is able to rescue the lethal phenotype of the yeast mutant, indicating that FBR12 is a functional eIF-5A. We propose that FBR12/eIF-5A-2 is fundamental for plant growth and development by regulating cell division, cell growth, and cell death.
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Haizhong
authors.initials: H
authors.lastname: Feng
authors.forename: Qingguo
authors.initials: Q
authors.lastname: Chen
authors.forename: Jian
authors.initials: J
authors.lastname: Feng
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yang
authors.forename: Jianru
authors.initials: J
authors.lastname: Zuo
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D016923:Cell Death / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D049108:Cell Enlargement; D003001:Cloning, Molecular; D003624:Darkness; D035264:Flowers / Q000254:growth & development; D037341:Fumonisins; D009154:Mutation; D010448:Peptide Initiation Factors / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology
chemical_list: D037341:Fumonisins; D010448:Peptide Initiation Factors; C425967:eIF-5A2; C056933:fumonisin B1