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Os ABCB 14 functions in auxin transport and iron homeostasis in rice ( Oryza sativa L.)
Author(s) -
Xu Yanxia,
Zhang Saina,
Guo Haipeng,
Wang Suikang,
Xu Ligen,
Li Chuanyou,
Qian Qian,
Chen Fan,
Geisler Markus,
Qi Yanhua,
Jiang De An
Publication year - 2014
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/tpj.12544
Subject(s) - auxin , mutant , atp binding cassette transporter , oryza sativa , biology , arabidopsis thaliana , myrosinase , microbiology and biotechnology , biochemistry , gene , transporter , botany , glucosinolate , brassica
Summary Members of the ATP Binding Cassette B/Multidrug‐Resistance/P–glyco‐protein ( ABCB / MDR / PGP ) subfamily were shown to function primarily in Oryza sativa (rice) auxin transport; however, none of the rice ABCB transporters have been functionally characterized. Here, we describe that a knock‐down of Os ABCB 14 confers decreased auxin concentrations and polar auxin transport rates, conferring insensitivity to 2,4‐dichlorophenoxyacetic acid (2,4–D) and indole‐3‐acetic acid ( IAA ). Os ABCB 14 displays enhanced specific auxin influx activity in yeast and protoplasts prepared from rice knock‐down alleles. Os ABCB 14 is localized at the plasma membrane, pointing to an important directionality under physiological conditions. osabcb14 mutants were surprisingly found to be insensitive to iron deficiency treatment (–Fe). Their Fe concentration is higher and upregulation of Fe deficiency‐responsive genes is lower in osabcb14 mutants than in wild‐type rice (Nipponbare, NIP ). Taken together, our results strongly support the role of Os ABCB 14 as an auxin influx transporter involved in Fe homeostasis. The functional characterization of Os ABCB 14 provides insights in monocot auxin transport and its relationship to Fe nutrition.