title: Proline affects the size of the root meristematic zone in Arabidopsis.
abstract: BACKGROUND
  We reported previously that root elongation in Arabidopsis is promoted by exogenous proline, raising the possibility that this amino acid may modulate root growth.
  
  
  RESULTS
  To evaluate this hypothesis we used a combination of genetic, pharmacological and molecular analyses, and showed that proline specifically affects root growth by modulating the size of the root meristem. The effects of proline on meristem size are parallel to, and independent from, hormonal pathways, and do not involve the expression of genes controlling cell differentiation at the transition zone. On the contrary, proline appears to control cell division in early stages of postembryonic root development, as shown by the expression of the G2/M-specific CYCLINB1;1 (CYCB1;1) gene.
  
  
  CONCLUSIONS
  The overall data suggest that proline can modulate the size of root meristematic zone in Arabidopsis likely controlling cell division and, in turn, the ratio between cell division and cell differentiation.
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. marco.biancucci@uniroma1.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Biancucci
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. roberto.mattioli@uniroma1.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mattioli
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. lailamoudayidin@gmail.com.
authors.forename: Laila
authors.initials: L
authors.lastname: Moubayidin
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. sabrina.sabatini@uniroma1.it.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Sabatini
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. paolo.costantino@uniroma1.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Costantino
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P.le Aldo Moro 5, 00185, Rome, Italy. maurizio.trovato@uniroma1.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Trovato
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism; D018519:Meristem / Q000033:anatomy & histology* / Q000254:growth & development*; D009154:Mutation / Q000235:genetics; D009929:Organ Size / Q000187:drug effects; D010937:Plant Growth Regulators / Q000494:pharmacology; D011392:Proline / Q000494:pharmacology*
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D011392:Proline