Premium
The auxin response factor, OsARF 19, controls rice leaf angles through positively regulating OsGH 3‐5 and OsBRI 1
Author(s) -
ZHANG SAINA,
WANG SUIKANG,
XU YANXIA,
YU CHENLIANG,
SHEN CHENJIA,
QIAN QIAN,
GEISLER MARKUS,
JIANG DE AN,
QI YANHUA
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12397
Subject(s) - auxin , brassinosteroid , microbiology and biotechnology , mutant , biology , lamina , chromatin immunoprecipitation , gene , arabidopsis , gene expression , botany , biochemistry , promoter
Auxin and brassinosteroid ( BR ) are important phytohormones for controlling lamina inclination implicated in plant architecture and grain yield. But the molecular mechanism of auxin and BR crosstalk for regulating lamina inclination remains unknown. Auxin response factors ( ARFs ) control various aspects of plant growth and development. We here report that OsARF 19‐ overexpression rice lines show an enlarged lamina inclination due to increase of its adaxial cell division. OsARF 19 is expressed in various organs including lamina joint and strongly induced by auxin and BR . Chromatin immunoprecipitation ( ChIP ) and yeast one‐hybrid assays demonstrate that OsARF 19 binds to the promoter of OsGH 3‐5 and brassinosteroid insensitive 1 ( OsBRI 1 ) directing their expression. OsGH 3‐5‐overexpression lines show a similar phenotype as OsARF 19‐ O 1 . Free auxin contents in the lamina joint of OsGH 3‐5‐ O 1 or OsARF 19‐ O 1 are reduced. OsGH 3‐5 is localized at the endoplasmic retieulum ( ER ) matching reduction of the free auxin contents in OsGH 3‐5‐ O 1 . osarf19 ‐ TDNA and osgh3‐5 ‐Tos17 mutants without erected leaves show a function redundancy with other members of their gene family. OsARF 19‐ overexpression lines are sensitive to exogenous BR treatment and alter the expressions of genes related to BR signalling. These findings provide novel insights into auxin and BR signalling, and might have significant implications for improving plant architecture of monocot crops.