A role for the rice homeobox gene Oshox1 in provascular cell fate commitment.
The vascular tissues of plants form a network of interconnected cell files throughout the plant body. The transition from a genetically totipotent meristematic precursor to different stages of a committed procambial cell, and its subsequent differentiation into a mature vascular element, involves developmental events whose molecular nature is still mostly unknown. The rice protein Oshox1 is a member of the homeodomain leucine zipper family of transcription factors. Here we show that the strikingly precise onset of Oshox1 gene expression marks critical, early stages of provascular ontogenesis in which the developmental fate of procambial cells is specified but not yet stably determined. This suggests that the Oshox1 gene may be involved in the establishment of the conditions required to restrict the developmental potential of procambial cells. In support of this hypothesis, ectopic expression of Oshox1 in provascular cells that normally do not yet express this gene results in anticipation of procambial cell fate commitment, eventually culminating in premature vascular differentiation. Oshox1 represents the first example of a transcription factor whose function can be linked to specification events mediating provascular cell fate commitment.
Institute of Molecular Plant Sciences, Leiden University, Clusius Laboratory, PO Box 9505, The Netherlands.
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Scarpella
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Rueb
K J
KJ
Boot
J H
JH
Hoge
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Meijer
D001692:Biological Transport; D002454:Cell Differentiation; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D017343:Genes, Plant; D005966:Glucuronidase / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism; D016350:Leucine Zippers; D012275:Oryza / Q000196:embryology / Q000235:genetics*; D010940:Plant Proteins; D012333:RNA, Messenger / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; C106325:Oshox1 protein, Oryza sativa; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors; D013395:Sucrose; D005966:Glucuronidase