title: RIMA-Dependent Nuclear Accumulation of IYO Triggers Auxin-Irreversible Cell Differentiation in Arabidopsis.
abstract: The transcriptional regulator MINIYO (IYO) is essential and rate-limiting for initiating cell differentiation inArabidopsis thalianaMoreover, IYO moves from the cytosol into the nucleus in cells at the meristem periphery, possibly triggering their differentiation. However, the genetic mechanisms controlling IYO nuclear accumulation were unknown, and the evidence that increased nuclear IYO levels trigger differentiation remained correlative. Searching for IYO interactors, we identified RPAP2 IYO Mate (RIMA), a homolog of yeast and human proteins linked to nuclear import of selective cargo. Knockdown ofRIMAcauses delayed onset of cell differentiation, phenocopying the effects ofIYOknockdown at the transcriptomic and developmental levels. Moreover, differentiation is completely blocked whenIYOandRIMAactivities are simultaneously reduced and is synergistically accelerated whenIYOandRIMAare concurrently overexpressed, confirming their functional interaction. Indeed,RIMAknockdown reduces the nuclear levels of IYO and prevents its prodifferentiation activity, supporting the conclusion that RIMA-dependent nuclear IYO accumulation triggers cell differentiation in Arabidopsis. Importantly, by analyzing the effect of the IYO/RIMA pathway on xylem pole pericycle cells, we provide compelling evidence reinforcing the view that the capacity for de novo organogenesis and regeneration from mature plant tissues can reside in stem cell reservoirs.
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Muñoz
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Silvina
authors.initials: S
authors.lastname: Mangano
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Mary Paz
authors.initials: MP
authors.lastname: González-García
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Contreras
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Michael
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: De Rybel
authors.affiliation: Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands.
authors.forename: Dolf
authors.initials: D
authors.lastname: Weijers
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain.
authors.forename: José Juan
authors.initials: JJ
authors.lastname: Sánchez-Serrano
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain msanmart@cnb.csic.es erojo@cnb.csic.es.
authors.forename: Maite
authors.identifier: http://orcid.org/0000-0003-2038-6580
authors.initials: M
authors.lastname: Sanmartín
authors.affiliation: Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain msanmart@cnb.csic.es erojo@cnb.csic.es.
authors.forename: Enrique
authors.identifier: http://orcid.org/0000-0001-9886-2917
authors.initials: E
authors.lastname: Rojo
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000166:cytology / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D008996:Monoamine Oxidase Inhibitors