title: Identification of two conserved cis-acting elements, MYCS and P1BS, involved in the regulation of mycorrhiza-activated phosphate transporters in eudicot species.
abstract: • In this study, six putative promoter regions of phosphate transporter Pht1;3, Pht1;4 and Pht1;5 genes were isolated from eggplant and tobacco using the inverse polymerase chain reaction (iPCR). The isolated sequences show evolutionary conservation and divergence within/between the two groups of Pht1;3 and Pht1;4/Pht1;5. • Histochemical analyses showed that all six promoter fragments were sufficient to drive β-glucuronidase (GUS) expression specifically in arbuscular mycorrhizal (AM) tobacco roots and were confined to distinct cells containing AM fungal structures (arbuscules or intracellular hyphae). • A series of promoter truncation and mutation analyses combined with phylogenetic footprinting of these promoters revealed that at least two cis-regulatory elements--the mycorrhiza transcription factor binding sequence (MYCS) first identified in this study and P1BS--mediated the transcriptional activation of the AM-mediated inorganic phosphate (Pi) transporter genes. Deletion or partial mutation of either of the two motifs in the promoters could cause a remarkable decrease, or even complete absence, of the promoter activity. • Our results propose that uptake of inorganic phosphate (Pi) by AM fungi is regulated, at least partially, in an MYCS- and P1BS-dependent manner in eudicot species. Our finding offers new insights into the molecular mechanisms underlying the coordination between the AM and the Pi signalling pathways.
authors.forename: Aiqun
authors.initials: A
authors.lastname: Chen
authors.forename: Mian
authors.initials: M
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shubin
authors.initials: S
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
mesh_terms: D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000378:metabolism*; D028061:Phosphate Transport Proteins / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D032323:Solanum melongena / Q000235:genetics; D013045:Species Specificity; D014026:Nicotiana / Q000235:genetics*
chemical_list: D028061:Phosphate Transport Proteins; D010940:Plant Proteins; D005966:Glucuronidase