title: Establishment of an in planta magnesium monitoring system using CAX3 promoter-luciferase in Arabidopsis.
abstract: The direct determination of elemental concentrations in plants is laborious. To overcome this, a novel monitoring system for magnesium (Mg) in plants was established. Mg deficiency-induced genes were identified by microarray analysis and transgenic lines that expressed luciferase (LUC) under the control of the Mg deficiency-inducible CAX3 promoter were established. The transgenic lines showed a clear response under low Mg conditions, and the degree of luminescence reflected the accumulation of endogenous CAX3 mRNA. The CAX3 expression pattern was also examined in a previously characterized low Mg-sensitive mutant, mrs2-7. In mrs2-7 mutant plants, CAX3 expression was more than three times higher than in the wild-type. In addition, CAX3 expression was negatively correlated with the shoot Mg concentration. Together, these results indicate that CAX3 transcription is a quantitative marker of the Mg status in Arabidopsis.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan. kamitake2007@gmail.com
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kamiya
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Yamagami
authors.forename: Masami Yokota
authors.initials: MY
authors.lastname: Hirai
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D017920:Antiporters / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D008156:Luciferases / Q000235:genetics*; D008274:Magnesium / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D017920:Antiporters; D029681:Arabidopsis Proteins; C506406:CAX3 protein, Arabidopsis; D017931:DNA Primers; D008156:Luciferases; D008274:Magnesium