WRKY6 is involved in the response to boron deficiency in Arabidopsis thaliana

Authors

  • Ichiro Kasajima,

    Corresponding author
    1. Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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    • Present address: Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

  • Yoko Ide,

    1. Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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  • Masami Yokota Hirai,

    1. Metabolomics Research Group, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
    2. CREST, Japan Science and Technology Agency, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012, Japan
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  • Toru Fujiwara

    1. Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
    2. Solution Oriented Research for Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
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* e-mail: kasajima2008@live.jp; kasajima@iam.u-tokyo.ac.jp

Abstract

Boron (B) is one of the essential nutrients for plant growth and reproduction. Transcriptome analyses have identified genes regulated by B deficiency, but their function mostly remains elusive. To identify the functions of B deficiency-inducible genes, T-DNA insertion mutants of 10 B deficiency-induced genes were obtained, and their growth properties in response to B conditions were examined. Among the lines examined, mutants of the transcription factor WRKY6 showed growth defect compared with the wild-type under B deficiency, but not under normal conditions. This growth defect was commonly observed among three independently isolated wrky6 mutants. There was no significant difference in B concentration between wrky6-3 and the wild-type. Promoter activity of WRKY6 was induced around the root tip under B deficiency. These results established that WRKY6 is a low-B-induced transcription factor gene that is essential for normal root growth under low-B conditions. Transcriptome analysis around the root tip identified WRKY6-regulated genes under B deficiency. Our findings represent the first identification of a transcription factor involved in the response to B deficiency.

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