AINTEGUMENTA and the D-type cyclin CYCD3;1 regulate root secondary growth and respond to cytokinins.
Higher plant vasculature is characterized by two distinct developmental phases. Initially, a well-defined radial primary pattern is established. In eudicots, this is followed by secondary growth, which involves development of the cambium and is required for efficient water and nutrient transport and wood formation. Regulation of secondary growth involves several phytohormones, and cytokinins have been implicated as key players, particularly in the activation of cell proliferation, but the molecular mechanisms mediating this hormonal control remain unknown. Here we show that the genes encoding the transcription factor AINTEGUMENTA (ANT) and the D-type cyclin CYCD3;1 are expressed in the vascular cambium of Arabidopsis roots, respond to cytokinins and are both required for proper root secondary thickening. Cytokinin regulation of ANT and CYCD3 also occurs during secondary thickening of poplar stems, suggesting this represents a conserved regulatory mechanism.
Department of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
Ricardo S
RS
Randall
Department of Biological Sciences, Osaka University, Graduate School of Science, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
Shunsuke
S
Miyashima
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Tiina
T
Blomster
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Jing
J
Zhang
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Annakaisa
A
Elo
Department of Plant Physiology, Umeå University, Umeå SE-901 87, Sweden.
Anna
A
Karlberg
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Juha
J
Immanen
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Kaisa
K
Nieminen
School of Biological Sciences, College of Natural Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
Ji-Young
JY
Lee
Department of Biological Sciences, Osaka University, Graduate School of Science, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
Tatsuo
T
Kakimoto
Sainsbury Laboratory, Cambridge University, Bateman Street, Cambridge CB2 1LR, UK.
Karolina
K
Blajecka
Sainsbury Laboratory, Cambridge University, Bateman Street, Cambridge CB2 1LR, UK.
Charles W
CW
Melnyk
Department of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
Annette
A
Alcasabas
Department of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
Celine
C
Forzani
Department of Biological Sciences, Osaka University, Graduate School of Science, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
Miho
M
Matsumoto-Kitano
Department of Biosciences, Institute of Biotechnology, Viikinkaari 1 (P.O.Box 65), 00014, University of Helsinki, Helsinki, Finland.
Ari Pekka
AP
Mähönen
Department of Plant Physiology, Umeå University, Umeå SE-901 87, Sweden.
Rishikesh
R
Bhalerao
Department of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
Walter
W
Dewitte
Sainsbury Laboratory, Cambridge University, Bateman Street, Cambridge CB2 1LR, UK murrayja1@cardiff.ac.uk yrjo.helariutta@helsinki.fi.
Ykä
Y
Helariutta
Department of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK murrayja1@cardiff.ac.uk yrjo.helariutta@helsinki.fi.
James A H
JA
Murray
AINTEGUMENTA; Cyclin D; Cytokinins; Root development; Secondary growth