title: Cosuppression of eukaryotic release factor 1-1 in Arabidopsis affects cell elongation and radial cell division.
abstract: The role of the eukaryotic release factor 1 (eRF1) in translation termination has previously been established in yeast; however, only limited characterization has been performed on any plant homologs. Here, we demonstrate that cosuppression of eRF1-1 in Arabidopsis (Arabidopsis thaliana) has a profound effect on plant morphology, resulting in what we term the broomhead phenotype. These plants primarily exhibit a reduction in internode elongation causing the formation of a broomhead-like cluster of malformed siliques at the top of the inflorescence stem. Histological analysis of broomhead stems revealed that cells are reduced in height and display ectopic lignification of the phloem cap cells, some phloem sieve cells, and regions of the fascicular cambium, as well as enhanced lignification of the interfascicular fibers. We also show that cell division in the fascicular cambial regions is altered, with the majority of vascular bundles containing cambial cells that are disorganized and possess enlarged nuclei. This is the first attempt at functional characterization of a release factor in vivo in plants and demonstrates the importance of eRF1-1 function in Arabidopsis.
authors.affiliation: Plant Genetic Engineering Laboratory, Department of Botany, School of Integrative Biology, University of Queensland, Brisbane, Australia.
authors.forename: Katherine Anne
authors.initials: KA
authors.lastname: Petsch
authors.forename: Joshua
authors.initials: J
authors.lastname: Mylne
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Botella
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division; D049108:Cell Enlargement; D015536:Down-Regulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D010454:Peptide Termination Factors / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics; D018547:Plant Stems / Q000378:metabolism; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010454:Peptide Termination Factors; D012333:RNA, Messenger; D018749:RNA, Plant; C494978:eukaryotic release factor 1, Arabidopsis