title: Differential expression of three BOR1 genes corresponding to different genomes in response to boron conditions in hexaploid wheat (Triticum aestivum L.).
abstract: Boron (B) is an essential micronutrient for plants. Efflux-type B transporters, BORs, have been identified in Arabidopsis thaliana and rice. Here we identified BOR1 genes encoding B efflux transporters, from the hexaploid genome of wheat (Triticum aestivum L.). We cloned three genes closely related to OsBOR1 and named them TaBOR1.1, TaBOR1.2 and TaBOR1.3. All three TaBOR1s showed B efflux activities when expressed in tobacco BY-2 cells. TaBOR1-green fluorescent protein (GFP) fusion proteins were expressed in Arabidopsis leaf cells localized in the plasma membrane. The transcript accumulation patterns of the three genes differ in terms of tissue specificity and B nutrition responses. In roots, transcripts for all three genes accumulated abundantly while in shoots, the TaBOR1.2 transcript is the most abundant, followed by those of TaBOR1.1 and TaBOR1.3. Accumulation of TaBOR1.1 transcript is up-regulated under B deficiency conditions in both roots and shoots. In contrast, TaBOR1.2 transcript accumulation significantly increased in roots under excess B conditions. TaBOR1.3 transcript accumulation was reduced under excess B. Taken together, these results demonstrated that TaBOR1s are the B efflux transporters in wheat and, interestingly, the genes on the A, B and D genomes have different expression patterns.
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan.
authors.forename: Sumana
authors.initials: S
authors.lastname: Leaungthitikanchana
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujibe
authors.forename: Mayuki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Sheliang
authors.initials: S
authors.lastname: Wang
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sotta
authors.forename: Junpei
authors.initials: J
authors.lastname: Takano
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D001895:Boron / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D011123:Polyploidy; D020033:Protein Isoforms / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014908:Triticum / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020033:Protein Isoforms; D049452:Green Fluorescent Proteins; D001895:Boron
keywords: BOR1; Boron; Nutrient response; Wheat