title: Differentially expressed small RNAs in Arabidopsis galls formed by Meloidogyne javanica: a functional role for miR390 and its TAS3-derived tasiRNAs.
abstract: Root-knot nematodes (RKNs) induce inside the vascular cylinder the giant cells (GCs) embedded in the galls. The distinctive gene repression in early-developing GCs could be facilitated by small RNAs (sRNA) such as miRNAs, and/or epigenetic mechanisms mediated by 24nt-sRNAs, rasiRNAs and 21-22nt-sRNAs. Therefore, the sRNA-population together with the role of the miR390/TAS3/ARFs module were studied during early gall/GC formation. Three sRNA libraries from 3-d-post-inoculation (dpi) galls induced by Meloidogyne javanica in Arabidopsis and three from uninfected root segments were sequenced following Illumina-Solexa technology. pMIR390a::GUS and pTAS3::GUS lines were assayed for nematode-dependent promoter activation. A sensor line indicative of TAS3-derived tasiRNAs binding to the ARF3 sequence (pARF3:ARF3-GUS) together with a tasiRNA-resistant ARF3 line (pARF3:ARF3m-GUS) were used for functional analysis. The sRNA population showed significant differences between galls and controls, with high validation rate and correspondence with their target expression: 21-nt sRNAs corresponding mainly to miRNAs were downregulated, whilst 24-nt-sRNAs from the rasiRNA family were mostly upregulated in galls. The promoters of MIR390a and TAS3, active in galls, and the pARF3:ARF3-GUS line, indicated a role of TAS3-derived-tasiRNAs in galls. The regulatory module miR390/TAS3 is necessary for proper gall formation possibly through auxin-responsive factors, and the abundance of 24-nt sRNAs (mostly rasiRNAs) constitutes a gall hallmark.
authors.affiliation: Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Cabrera
authors.affiliation: Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Barcala
authors.affiliation: Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain.
authors.forename: Alejandra
authors.initials: A
authors.lastname: García
authors.affiliation: Molecular Cytogenetics Group, Human Cancer Genetics Programme, Centro Nacional Investigaciones Oncológicas (CNIO), C/Melchor Fernández Almagro, 3, 28029 , Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Rio-Machín
authors.affiliation: INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Medina
authors.affiliation: INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Jaubert-Possamai
authors.affiliation: INRA, Université Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900, Sophia Antipolis, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Favery
authors.affiliation: Centre for Organismal Studies University of Heidelberg, Im Neuenheimer Feld, 230-69120, Heidelberg, Germany.
authors.forename: Alexis
authors.initials: A
authors.lastname: Maizel
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Av. Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Ruiz-Ferrer
authors.affiliation: Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Fenoll
authors.affiliation: Universidad de Castilla-La Mancha, Facultad de Ciencias Ambientales y Bioquímica, Avda. Carlos III, s/n 45071, Toledo, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Escobar
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000469:parasitology; D001483:Base Sequence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D018745:Genome, Plant; D005966:Glucuronidase / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009711:Nucleotides / Q000235:genetics; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology; D018517:Plant Roots / Q000235:genetics; D010941:Plant Tumors / Q000235:genetics / Q000469:parasitology*; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014431:Tylenchoidea
chemical_list: C584086:MIRN390 microRNA, Arabidopsis; D035683:MicroRNAs; D009711:Nucleotides; D018749:RNA, Plant; D034741:RNA, Small Interfering; D005966:Glucuronidase
keywords: galls; giant cells; meloidogyne; miRNAs; rasiRNAs; silencing; small RNAs; tasiRNAs