title: Suppression of RICE TELOMERE BINDING PROTEIN 1 results in severe and gradual developmental defects accompanied by genome instability in rice.
abstract: Although several potential telomere binding proteins have been identified in higher plants, their in vivo functions are still unknown at the plant level. Both knockout and antisense mutants of RICE TELOMERE BINDING PROTEIN1 (RTBP1) exhibited markedly longer telomeres relative to those of the wild type, indicating that the amount of functional RTBP1 is inversely correlated with telomere length. rtbp1 plants displayed progressive and severe developmental abnormalities in both germination and postgermination growth of vegetative organs over four generations (G1 to G4). Reproductive organ formation, including panicles, stamens, and spikelets, was also gradually and severely impaired in G1 to G4 mutants. Up to 11.4, 17.2, and 26.7% of anaphases in G2, G3, and G4 mutant pollen mother cells, respectively, exhibited one or more chromosomal fusions, and this progressively increasing aberrant morphology was correlated with an increased frequency of anaphase bridges containing telomeric repeat DNA. Furthermore, 35S:anti-RTBP1 plants expressing lower levels of RTBP1 mRNA exhibited developmental phenotypes intermediate between the wild type and mutants in all aspects examined, including telomere length, vegetative and reproductive growth, and degree of genomic anomaly. These results suggest that RTBP1 plays dual roles in rice (Oryza sativa), as both a negative regulator of telomere length and one of positive and functional components for proper architecture of telomeres.
authors.affiliation: Department of Biology, College of Science, Yonsei University, Seoul, Korea.
authors.forename: Jong-Pil
authors.initials: JP
authors.lastname: Hong
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Byun
authors.forename: Dal-Hoe
authors.initials: DH
authors.lastname: Koo
authors.forename: Kyungsook
authors.initials: K
authors.lastname: An
authors.forename: Jae-Wook
authors.initials: JW
authors.lastname: Bang
authors.forename: In Kwon
authors.initials: IK
authors.lastname: Chung
authors.forename: Gynheung
authors.initials: G
authors.lastname: An
authors.forename: Woo Taek
authors.initials: WT
authors.lastname: Kim
mesh_terms: D020732:Cytogenetic Analysis; D004269:DNA, Bacterial; D035264:Flowers / Q000254:growth & development; D018745:Genome, Plant; D042822:Genomic Instability; D016254:Mutagenesis, Insertional; D050505:Mutant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000166:cytology; D013489:Suppression, Genetic; D016615:Telomere / Q000378:metabolism; D034501:Telomere-Binding Proteins / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D050505:Mutant Proteins; D010940:Plant Proteins; C036483:T-DNA; D034501:Telomere-Binding Proteins; C440852:telomere binding protein-1, Oryza sativa