State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
New Phytol. 2012 Oct;196(1):139-148. doi: 10.1111/j.1469-8137.2012.04227.x. Epub 2012 Jul 17.
• 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.
• 含有 SPX 结构域的蛋白质存在于几种参与酵母和植物中无机磷（Pi）运输和信号转导的蛋白质中。尽管最近已经揭示了几个 SPX 结构域蛋白亚家族的功能，但 SPX-MFS 亚家族的作用仍不清楚。• 使用定量 RT-PCR 分析，我们研究了中央调节剂 OsPHR2 和 Pi 饥饿对 SPX-MFS 基因表达的调控。使用 OsSPX-MFS1 突变体（mfs1）和 osa-miR827 过表达系（miR827-Oe）分析了 OsSPX-MFS1 在 Pi 稳态中的功能。最后，使用酵母突变体中 Pi 转运体的异源互补来评估 OsSPX-MFS1 转运 Pi 的能力。• 转录分析显示，SPX-MFS 家族的成员主要在地上部分表达，OsSPX-MFS1 和 OsSPX-MFS3 受 Pi 缺乏的抑制，而 OsSPX-MFS2 被诱导。OsSPX-MFS1 突变（mfs1）和上游 miR827 的过表达（miR827-Oe）植物损害了叶片中的 Pi 稳态。此外，酵母研究表明，OsSPX-MFS1 可能参与 Pi 转运。• 结果表明，OsSPX-MFS1 是维持叶片中 Pi 稳态的关键因子，可能作为 Pi 转运体发挥作用。
