Functional characterization of the rice SPX-MFS family reveals a key role of OsSPX-MFS1 in controlling phosphate homeostasis in leaves

Authors

  • Chuang Wang,

    1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
    2. Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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    • These authors contributed equally to this work.

  • Wei Huang,

    1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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    • These authors contributed equally to this work.

  • Yinghui Ying,

    1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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  • Shuai Li,

    1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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  • David Secco,

    1. Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
    2. Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, WA, Australia
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  • Steve Tyerman,

    1. Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
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  • James Whelan,

    1. Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
    2. Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, WA, Australia
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  • Huixia Shou

    1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
    2. Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
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Author for correspondence:
Huixia Shou
Tel: +86 0571 88206133
Email: huixia@zju.edu.cn

Summary

  • Proteins possessing the SPX domain are found in several proteins involved in inorganic phosphate (Pi) transport and signalling in yeast and plants. Although the functions of several SPX-domain protein subfamilies have recently been uncovered, the role of the SPX-MFS subfamily is still unclear.
  • Using quantitative RT-PCR analysis, we studied the regulation of SPX-MFS gene expression by the central regulator, OsPHR2 and Pi starvation. The function of OsSPX-MFS1 in Pi homeostasis was analysed using an OsSPX-MFS1 mutant (mfs1) and osa-miR827 overexpression line (miR827-Oe). Finally, heterologous complementation of a yeast mutant impaired in Pi transporter was used to assess the capacity of OsSPX-MFS1 to transport Pi.
  • Transcript analyses revealed that members of the SPX-MFS family were mainly expressed in the shoots, with OsSPX-MFS1 and OsSPX-MFS3 being suppressed by Pi deficiency, while OsSPX-MFS2 was induced. Mutation in OsSPX-MFS1 (mfs1) and overexpression of the upstream miR827 (miR827-Oe) plants impaired Pi homeostasis in the leaves. In addition, studies in yeast revealed that OsSPX-MFS1 may be involved in Pi transport.
  • The results suggest that OsSPX-MFS1 is a key player in maintaining Pi homeostasis in the leaves, potentially acting as a Pi transporter.

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