title: RNA-Seq analysis discloses early senescence and nucleolar dysfunction triggered by Tdp1α depletion in Medicago truncatula.
abstract: An intron-spliced hairpin RNA approach was used for the targeted silencing of the MtTdp1α gene encoding the αisoform of tyrosyl-DNA phosphodiesterase 1 in Medicago truncatula Gaertn. Tyrosyl-DNA phosphodiesterase 1, involved in the repair of DNA topoisomerase I-mediated DNA damage, has been poorly investigated in plants. RNA-Seq analysis, carried out in the MtTdp1α-depleted plants, revealed different levels of transcriptional modulation (up- and down-regulation, alternative splicing, activation of alternative promoter) in genes involved in DNA damage sensing, DNA repair, and chromatin remodelling. It is suggested that the MtTdp1α gene has new, previously undetected roles in maintaining genome integrity. Up-regulation of senescence-associated genes and telomere shortening were observed. Moreover, impaired ribosome biogenesis indicated that the MtTdp1α gene is required for the nucleolar function. In agreement with the RNA-Seq data, transmission electron microscopy detected an altered nucleolar architecture in the MtTdp1α-depleted cells. Based on the reported data, a working hypothesis related to the occurrence of a nucleolar checkpoint in plant cells is proposed.
authors: Department of Biology and Biotechnology L Spallanzani, via Ferrata 1, 27100 Pavia, Italy.
authors: Mattia
authors: M
authors: Donà
authors: Massimo
authors: M
authors: Confalonieri
authors: Andrea
authors: A
authors: Minio
authors: Marco
authors: M
authors: Biggiogera
authors: Armando
authors: A
authors: Buttafava
authors: Elena
authors: E
authors: Raimondi
authors: Massimo
authors: M
authors: Delledonne
authors: Lorenzo
authors: L
authors: Ventura
authors: Maria Elisa
authors: ME
authors: Sabatini
authors: Anca
authors: A
authors: Macovei
authors: Giorgio
authors: G
authors: Giraffa
authors: Daniela
authors: D
authors: Carbonera
authors: Alma
authors: A
authors: Balestrazzi
mesh_terms: D016922:Cellular Senescence / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D046913:Medicago truncatula / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D010727:Phosphoric Diester Hydrolases; C122147:tyrosyl-DNA phosphodiesterase