Identification of plant vacuolar transporters mediating phosphate storage
Plant vacuoles serve as the primary intracellular compartments for inorganic phosphate (Pi) storage. Passage of Pi across vacuolar membranes plays a critical role in buffering the cytoplasmic Pi level against fluctuations of external Pi and metabolic activities. Here we demonstrate that the SPX-MFS proteins, designated as PHOSPHATE TRANSPORTER 5 family (PHT5), also named Vacuolar Phosphate Transporter (VPT), function as vacuolar Pi transporters. Based on 31P-magnetic resonance spectroscopy analysis, Arabidopsis pht5;1 loss-of-function mutants accumulate less Pi and exhibit a lower vacuolar-to-cytoplasmic Pi ratio than controls. Conversely, overexpression of PHT5 leads to massive Pi sequestration into vacuoles and altered regulation of Pi starvation-responsive genes. Furthermore, we show that heterologous expression of the rice homologue OsSPX-MFS1 mediates Pi influx to yeast vacuoles. Our findings show that a group of Pi transporters in vacuolar membranes regulate cytoplasmic Pi homeostasis and are required for fitness and plant growth.Tzyy-Jen Chiou
Distinguished Research Fellow
(02) 2787-2051
tjchiou@gate.sinica.edu.tw
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- 1995 Ph.D. Physiological and Molecular Plant Biology Program, Univ. of Illinois, USA
- 1995-1997 PDF Dept. of Plant Biology, Univ. of Illinois, USA
- 1997-1998 PDF Dept. of Food Science, Univ. of Illinois, USA
- 1998-2000 PDF Plant Biology Div., Noble Foundation, USA
- 2000-2007 Assistant Research Fellow Inst. of BioAgric. Sci., Academia Sinica
- 2007-2012 Associate Research Fellow
- 2012-2018 Research Fellow
- 2014-2016 Vice Director
- 2018-Distinguished Research Fellow
- 2018-Deputy Executive Secretary