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Production and characterization of auxin‐insensitive rice by overexpression of a mutagenized rice IAA protein
Author(s) -
Nakamura Ayako,
Umemura Iichiro,
Gomi Kenji,
Hasegawa Yasuko,
Kitano Hidemi,
Sazuka Takashi,
Matsuoka Makoto
Publication year - 2006
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2006.02693.x
Subject(s) - auxin , arabidopsis , oryza sativa , mutant , genetically modified rice , biology , gene , transgene , microbiology and biotechnology , plant hormone , arabidopsis thaliana , genetically modified crops , botany , genetics
Summary Since auxin was first isolated and characterized as a plant hormone, the underlying molecular mechanism of auxin signaling has been elucidated primarily in dicot plants represented by Arabidopsis. In monocot plants, the molecular mechanism of auxin signaling has remained unclear, despite various physiological experiments. To understand the function and mechanism of auxin signaling in rice ( Oryza sativa ), we focused on the IAA gene, a well‐studied gene in Arabidopsis that serves as a negative regulator of auxin signaling. We found 24 IAA gene family members in the rice genome. OsIAA3 is one of these family members whose expression is rapidly increased in response to auxin. We produced transgenic rice harboring m OsIAA3 ‐ GR , which can overproduce mutant OsIAA3 protein containing an amino acid change in domain II to cause a gain‐of‐function phenotype, by treatment with dexamethasone. The transgenic rice was insensitive to auxin and gravitropic stimuli, and exhibited short leaf blades, reduced crown root formation, and abnormal leaf formation. These results suggest that, in rice, auxin is important for development and its signaling is mediated by IAA genes.