Arbuscular Mycorrhizal Symbiosis Requires a Phosphate Transceptor in the Gigaspora margarita Fungal Symbiont.
The majority of terrestrial vascular plants are capable of forming mutualistic associations with obligate biotrophic arbuscular mycorrhizal (AM) fungi from the phylum Glomeromycota. This mutualistic symbiosis provides carbohydrates to the fungus, and reciprocally improves plant phosphate uptake. AM fungal transporters can acquire phosphate from the soil through the hyphal networks. Nevertheless, the precise functions of AM fungal phosphate transporters, and whether they act as sensors or as nutrient transporters, in fungal signal transduction remain unclear. Here, we report a high-affinity phosphate transporter GigmPT from Gigaspora margarita that is required for AM symbiosis. Host-induced gene silencing of GigmPT hampers the development of G. margarita during AM symbiosis. Most importantly, GigmPT functions as a phosphate transceptor in G. margarita regarding the activation of the phosphate signaling pathway as well as the protein kinase A signaling cascade. Using the substituted-cysteine accessibility method, we identified residues A146(in transmembrane domain [TMD] IV) and Val357(in TMD VIII) of GigmPT, both of which are critical for phosphate signaling and transport in yeast during growth induction. Collectively, our results provide significant insights into the molecular functions of a phosphate transceptor from the AM fungus G. margarita.
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Xianan
X
Xie
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Hui
H
Lin
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Xiaowei
X
Peng
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Congrui
C
Xu
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Zhongfeng
Z
Sun
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Kexin
K
Jiang
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Antian
A
Huang
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Xiaohui
X
Wu
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China.
Nianwu
N
Tang
Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125 Torino, Italy.
Alessandra
A
Salvioli
Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125 Torino, Italy.
Paola
P
Bonfante
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R.China. Electronic address: binzhao@mail.hzau.edu.cn.
Bin
B
Zhao
D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055137:Glomeromycota / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D025301:Hyphae / Q000378:metabolism / Q000502:physiology; D038821:Mycorrhizae / Q000378:metabolism* / Q000502:physiology*; D013559:Symbiosis / Q000235:genetics / Q000502:physiology*
D017868:Cyclic AMP-Dependent Protein Kinases
Gigaspora margarita; GigmPT; mutualistic symbiosis; phosphate signaling; phosphate transceptor; protein kinase A