A H+-ATPase That Energizes Nutrient Uptake during Mycorrhizal Symbioses in Rice and Medicago truncatula.
Most plant species form symbioses with arbuscular mycorrhizal (AM) fungi, which facilitate the uptake of mineral nutrients such as phosphate from the soil. Several transporters, particularly proton-coupled phosphate transporters, have been identified on both the plant and fungal membranes and contribute to delivering phosphate from fungi to plants. The mechanism of nutrient exchange has been studied in plants during mycorrhizal colonization, but the source of the electrochemical proton gradient that drives nutrient exchange is not known. Here, we show that plasma membrane H+-ATPases that are specifically induced in arbuscule-containing cells are required for enhanced proton pumping activity in membrane vesicles from AM-colonized roots of rice (Oryza sativa) and Medicago truncatula. Mutation of the H+-ATPases reduced arbuscule size and impaired nutrient uptake by the host plant through the mycorrhizal symbiosis. Overexpression of the H+-ATPase Os-HA1 increased both phosphate uptake and the plasma membrane potential, suggesting that this H+-ATPase plays a key role in energizing the periarbuscular membrane, thereby facilitating nutrient exchange in arbusculated plant cells.
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China John Innes Centre, Norwich NR4 7UH, United Kingdom etwang@sibs.ac.cn.
Ertao
E
Wang
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China John Innes Centre, Norwich NR4 7UH, United Kingdom.
Nan
N
Yu
Department of Biology, University of York, York YO10 5DD, United Kingdom.
S Asma
SA
Bano
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Chengwu
C
Liu
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Anthony J
AJ
Miller
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Donna
D
Cousins
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Xiaowei
X
Zhang
Institut des Sciences du Végétale, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France.
Pascal
P
Ratet
Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401.
Million
M
Tadege
Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401.
Kirankumar S
KS
Mysore
John Innes Centre, Norwich NR4 7UH, United Kingdom.
J Allan
JA
Downie
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Jeremy D
JD
Murray
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Giles E D
GE
Oldroyd
Department of Biology, University of York, York YO10 5DD, United Kingdom.
Michael
M
Schultze