title: Overexpression of Arabidopsis thaliana ERI, the homolog of C. elegans Enhancer of RNAinterference, leads to enhanced growth.
abstract: Organisms adopt a wide range of strategies to adapt to change. Gene silencing describes the ability of organisms to modulate the expression of susceptible genes at certain times at the transcriptional or the translational level. In all known eukaryotic organisms 21-nt long short interfering RNAs (siRNAs) are the effector molecules of post-transcriptional gene silencing (PTGS), while 24-nt long siRNAs are involved in PTGS in plants. Mutant studies in Caenorhabditis elegans lead to the identification of the enzyme ERI (Enhancer of RNAinterference) with enhanced PTGS. Although the genes involved in growth vigor and growth rate are still unknown, it becomes clearer that the population of small RNAs plays a role in the very early phase of plant development. To pinpoint the link between growth and siRNAs, the expression of Arabidopsis uni-gene Enhancer of RNAi (ERI) homolog from C. elegans was modulated. Increased degradation of small RNAs was achieved by ectopic AtERI overexpression in planta. Based on global small RNA analysis, AtERI overexpression affects mainly the population of 21 mers, excluding miRNAs. To identify target genes, AtERI gain-of-function mutants were analyzed, and differentially abundant small RNAs were identified. Plants with an elevated level of AtERI were bigger in all three light intensities analyzed, indicating an inhibitory function of particular small RNAs in plant growth, with differences in relative growth rates depending on developmental stage and light intensity. Understanding the role of these siRNAs could open new avenues for enhancing plant growth.
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Rhonda C
authors.initials: RC
authors.lastname: Meyer
authors.affiliation: Department of Developmental Genetics, Institute of Biology, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Hönig
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Ronny
authors.initials: R
authors.lastname: Brandt
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Fernando
authors.initials: F
authors.lastname: Arana-Ceballos
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Cathleen
authors.initials: C
authors.lastname: Neitsch
authors.affiliation: Department of Developmental Genetics, Institute of Biology, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Reuter
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) , Stadt Seeland, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kuhlmann
keywords: Arabidopsis; ERI; Enhancer of RNAi; biomass; enhanced growth; small RNA