Auxin-associated initiation of vascular cell differentiation by LONESOME HIGHWAY.
Plant vascular tissues are essential for the existence of land plants. Many studies of transcriptional regulation and cell-cell communication have revealed the process underlying the development of vascular tissues from vascular initial cells. However, the initiation of vascular cell differentiation is still a mystery. Here, we report that LONESOME HIGHWAY (LHW), which encodes a bHLH transcription factor, is expressed in pericycle-vascular mother cells at the globular embryo stage and is required for proper asymmetric cell division to generate vascular initial cells. In addition, ectopic expression of LHW elicits an ectopic auxin response. Moreover, LHW is required for the correct expression patterns of components related to auxin flow, such as PIN-FORMED 1 (PIN1), MONOPTEROS (MP) and ATHB-8, and ATHB-8 partially rescues the vascular defects of lhw. These results suggest that LHW functions as a key regulator to initiate vascular cell differentiation in association with auxin regulation.
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. kyoko@biol.s.u-tokyo.ac.jp
Kyoko
K
Ohashi-Ito
Mio
M
Oguchi
Mikiko
M
Kojima
Hitoshi
H
Sakakibara
Hiroo
H
Fukuda
D017360:Arabidopsis / Q000196:embryology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D005822:Genetic Vectors / Q000235:genetics; D006652:Histological Techniques; D021621:Imaging, Three-Dimensional; D017403:In Situ Hybridization; D007210:Indoleacetic Acids / Q000378:metabolism*; D058526:Plant Vascular Bundle / Q000166:cytology* / Q000196:embryology; D060888:Real-Time Polymerase Chain Reaction; D015534:Trans-Activators / Q000378:metabolism*
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C523529:LHW protein, Arabidopsis; D015534:Trans-Activators