title: The KNOTTED-like genes of peach (Prunus persica L. Batsch) are differentially expressed during drupe growth and the class 1 KNOPE1 contributes to mesocarp development.
abstract: The Knotted-like transcription factors (KNOX) contribute to plant organ development. The expression patterns of peach KNOX genes showed that the class 1 members act precociously (S1-S2 stages) and differentially during drupe growth. Specifically, the transcription of KNOPE1 and 6 decreased from early (cell division) to late (cell expansion) S1 sub-stages, whilst that of STMlike1, 2, KNOPE2, 2.1 ceased at early S1. The KNOPE1 role in mesocarp was further addressed by studying the mRNA localization in the pulp cells and vascular net at early and late S1. The message signal was first diffuse in parenchymatous cells and then confined to hypodermal cell layers, showing that the gene down-tuning accompanied cell expansion. As for bundles, the mRNA mainly featured in the procambium/phloem of collateral open types and subsequently in the phloem side of complex structures (converging bundles, ducts). The KNOPE1 overexpression in Arabidopsis caused fruit shortening, decrease of mesocarp cell size, diminution of vascular lignification together with the repression of the major gibberellin synthesis genes AtGA20ox1 and AtGA3ox1. Negative correlation between the expression of KNOPE1 and PpGA3ox1 was observed in four cultivars at S1, suggesting that the KNOPE1 repression of PpGA3ox1 may regulate mesocarp differentiation by acting on gibberellin homeostasis.
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council of Italy (CNR), via Salaria km 29,300, 00015 Monterotondo Scalo, Rome, Italy. Electronic address: testone@ibba.cnr.it.
authors.forename: Giulio
authors.initials: G
authors.lastname: Testone
authors.affiliation: Fruit Tree Research Centre, Agriculture Research Council (CRA), Via di Fioranello 52, 00134 Rome, Italy. Electronic address: emiliano.condello@entecra.it.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Condello
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council of Italy (CNR), via Salaria km 29,300, 00015 Monterotondo Scalo, Rome, Italy. Electronic address: digiacomo@ibba.cnr.it.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Di Giacomo
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council of Italy (CNR), via Salaria km 29,300, 00015 Monterotondo Scalo, Rome, Italy. Electronic address: nicolodi@ibba.cnr.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Nicolodi
authors.affiliation: Fruit Tree Research Centre, Agriculture Research Council (CRA), Via di Fioranello 52, 00134 Rome, Italy. Electronic address: emilia.caboni@entecra.it.
authors.forename: Emilia
authors.initials: E
authors.lastname: Caboni
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), University of Padova, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: angela.rasori@unipd.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Rasori
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), University of Padova, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: claudio.bonghi@unipd.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonghi
authors.affiliation: Department of Ecology, University of Calabria, Ponte Bucci, 87030 Arcavacata di Rende, Cosenza, Italy. Electronic address: l.bruno@unical.it.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Bruno
authors.affiliation: Department of Ecology, University of Calabria, Ponte Bucci, 87030 Arcavacata di Rende, Cosenza, Italy. Electronic address: b.bitonti@unical.it.
authors.forename: Maria Beatrice
authors.initials: MB
authors.lastname: Bitonti
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council of Italy (CNR), via Salaria km 29,300, 00015 Monterotondo Scalo, Rome, Italy. Electronic address: donato.giannino@ibba.cnr.it.
authors.forename: Donato
authors.initials: D
authors.lastname: Giannino
mesh_terms: D005638:Fruit / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006706:Homeostasis; D052585:Phloem / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D000068239:Prunus persica / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D005875:Gibberellins; D018398:Homeodomain Proteins; C095848:Kn1 protein, plant; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger
keywords: Class 1 KNOPE1; Drupe development; Gibberellin synthesis genes; KNOX transcription factors; Mesocarp development; Peach