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Root hair‐specific expansins modulate root hair elongation in rice
Author(s) -
ZhiMing Yu,
Bo Kang,
XiaoWei He,
ShaoLei Lv,
YouHuang Bai,
WoNa Ding,
Ming Chen,
HyungTaeg Cho,
Ping Wu
Publication year - 2011
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.2011.04533.x
Subject(s) - root hair , mutant , expansin , biology , elongation , microbiology and biotechnology , arabidopsis , oryza sativa , complementation , gene , biochemistry , gene expression , materials science , ultimate tensile strength , metallurgy
Summary Root hair growth requires intensive cell‐wall modification. This study demonstrates that root hair‐specific expansin As, a sub‐clade of the cell wall‐loosening expansin proteins, are required for root hair elongation in rice ( Oryza sativa L.). We identified a gene encoding EXPA17 ( OsEXPA17 ) from a rice mutant with short root hairs. Promoter::reporter transgenic lines exhibited exclusive OsEXPA17 expression in root hair cells. The OsEXPA17 mutant protein (OsexpA17) contained a point mutation, causing a change in the amino acid sequence (Gly104→Arg). This amino acid alteration is predicted to disrupt a highly conserved disulfide bond in the mutant. Suppression of OsEXPA17 by RNA interference further confirmed requirement for the gene in root hair elongation. Complementation of the OsEXPA17 mutant with other root hair EXPAs (OsEXPA30 and Arabidopsis EXPA7) can restore root hair elongation, indicating functional conservation of these root hair EXPAs in monocots and dicots. These results demonstrate that members of the root hair EXPA sub‐clade play a crucial role in root hair cell elongation in Graminaceae.