Identification and expression analysis of arbuscular mycorrhiza-inducible phosphate transporter genes of soybean.
Soybeans, the world's leading leguminous crop, establish mutualistic symbiosis with arbuscular mycorrhizal (AM) fungi. AM fungi colonize root cortical cells forming arbuscules, highly branched fungal structures. Arbuscules are enveloped by plant-derived periarbuscular membranes through which plants obtain mineral nutrients, particularly phosphate. We searched the soybean genome in silico, and found 14 Pht1 genes encoding phosphate transporters putatively localized on the plasma membranes. Time course analyses involving reverse transcription-PCR indicated that three of these were AM-inducible. GmPT10 and GmPT11 were induced on fungal colonization, while a transcript of GmPT7 appeared in the later stages. The transport activities of GmPT10 and GmPT11 were confirmed by complementation of a yeast mutant. Soybean hairy roots expressing the GmPT10-green fluorescent protein (GFP) or GmPT11-GFP fusion protein under the control of corresponding promoter showed GFP fluorescence on the branch domains of periarbuscular membranes, indicating that active phosphate transport occurred there.
Laboratory of Crop Science, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
Yosuke
Y
Tamura
Yoshihiro
Y
Kobae
Toyotaka
T
Mizuno
Shingo
S
Hata
D019295:Computational Biology; D030561:Databases, Nucleic Acid; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D038821:Mycorrhizae / Q000235:genetics*; D028061:Phosphate Transport Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D013025:Glycine max / Q000737:chemistry / Q000235:genetics*; D013559:Symbiosis / Q000235:genetics*; D015533:Transcriptional Activation
D028061:Phosphate Transport Proteins; D010940:Plant Proteins