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Identification of CROWN ROOTLESS 1‐regulated genes in rice reveals specific and conserved elements of postembryonic root formation
Author(s) -
Coudert Yoan,
Le Van Anh Thi,
Adam Hélène,
Bès Martine,
Vignols Florence,
Jouannic Stefan,
Guiderdoni Emmanuel,
Gantet Pascal
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13196
Subject(s) - biology , primordium , gene , meristem , homeobox , transcription factor , oryza sativa , genetics , auxin , microbiology and biotechnology , transcriptome , botany , gene expression
Summary In monocotyledons, the root system is mostly composed of postembryonic shoot‐borne roots called crown roots. In rice ( Oryza sativa ), auxin promotes crown root initiation via the LOB ‐domain transcription factor ( LBD ) transcription factor CROWN ROOTLESS 1 ( CRL 1); however, the gene regulatory network downstream of CRL 1 remains largely unknown. We tested CRL 1 transcriptional activity in yeast and in planta , identified CRL 1‐regulated genes using an inducible gene expression system and a transcriptome analysis, and used in situ hybridization to demonstrate coexpression of a sample of CRL 1‐regulated genes with CRL 1 in crown root primordia. We show that CRL 1 positively regulates 277 genes, including key genes involved in meristem patterning (such as QUIESCENT ‐ CENTER SPECIFIC HOMEOBOX ; QHB ), cell proliferation and hormone homeostasis. Many genes are homologous to A rabidopsis genes involved in lateral root formation, but about a quarter are rice‐specific. Our study reveals that several genes acting downstream of LBD transcription factors controlling postembryonic root formation are conserved between monocots and dicots. It also provides evidence that specific genes are involved in the formation of shoot‐derived roots in rice.