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An Al‐inducible expansin gene, Os EXPA 10 is involved in root cell elongation of rice
Author(s) -
Che Jing,
Yamaji Naoki,
Shen Ren Fang,
Ma Jian Feng
Publication year - 2016
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.13237
Subject(s) - expansin , elongation , microbiology and biotechnology , gene expression , biology , gene , endodermis , cell wall , root hair , oryza sativa , downregulation and upregulation , botany , biochemistry , materials science , ultimate tensile strength , metallurgy
Summary Expansins are cell wall loosening proteins, which are encoded by multigene families. However, the physiological role of most expansin genes is still poorly understood. Here, we functionally characterized an Al‐inducible expansin gene, Os EXPA 10 , which is regulated by a C2H2‐type zinc‐finger transcription factor, ART 1 in rice. A detailed expression analysis showed that Os EXPA 10 was expressed in both the roots and shoots at a similar level, but only the expression in the roots was rapidly upregulated in response to Al. Furthermore, spatial expression analysis showed that the Al‐induced expression was only found in the root tips (0–3 mm), but not in the mature root zones. The expression was neither induced by other metals including Cd and La nor by low pH . Immunostaining showed that Os EXPA 10 was localized at all cells of the root tips. Knockout of Os EXPA 10 resulted in a significant decrease in the cell elongation of the roots in the absence of Al. In the presence of Al, knockout of Os EXPA 10 did not alter the Al sensitivity evaluated by relative root elongation, but the root cell wall of knockout lines accumulated less Al compared to those of the wild‐type rice. Collectively, our results indicate that Os EXPA 10 expressed in the root tips is required for the root cell elongation, but that the contribution of this gene to high Al tolerance in rice is small.