title: Magnesium Transporter 5 plays an important role in Mg transport for male gametophyte development in Arabidopsis.
abstract: During anther development the male gametophyte develops inside the locule and the tapetal cells provide all nutrients for its development. Magnesium Transporter 5 (MGT5) is a member of the MGT family and has dual functions of Mg export and import. Here, we show that male gametophyte mitosis and intine formation are defective in a mgt5 mutant. The transient expression of GFP-MGT5 revealed that MGT5 is localized in the plasma membrane. These findings suggest that in the male gametophyte MGT5 plays a role in importing Mg from the locule and that Mg is essential for male gametophyte development. The expression of MGT5 in the knockout ABORTED MICROSPORES (AMS) mutant (AMS being an essential regulator of tapetum) is tremendously reduced. Chromatin immunoprecipitation and mobility shift assay experiments demonstrated that AMS can directly bind the promoter of MGT5. An immunoelectron microscopy assay revealed that MGT5-His is localized to the plasma membrane of the tapetum. These findings suggest that AMS directly regulates MGT5 in the tapetum and thus induces export of Mg into the locule. The mgt5 plant exhibits severe male sterility while the expression of MGT5 under the tapetum-specific promoter A9 partly rescued mgt5 fertility. mgt5 fertility was restored under high-Mg conditions. These findings suggest that the mgt5 tapetum still has the ability to export Mg and that a sufficient supply of Mg from the tapetum can improve the importation of Mg in the mgt5 male gametophyte. Therefore, MGT5 plays an important role in Mg transport from the tapetum to the microspore.
authors.affiliation: Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China.|College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Xu
authors.affiliation: Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China.|College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lou
authors.affiliation: College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Wen-Jian
authors.initials: WJ
authors.lastname: Han
authors.affiliation: College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Jie-Yang
authors.initials: JY
authors.lastname: Lu
authors.affiliation: College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Li
authors.affiliation: College of Life Sciences, Capital Normal University, Beijing, 100048, China.
authors.forename: Le-Gong
authors.initials: LG
authors.lastname: Li
authors.affiliation: Department of Molecular and Cell Biology, School of Life Science and Technology, Tongji University, Shanghai, 200092, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors.forename: Zhong-Nan
authors.initials: ZN
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D055786:Gene Knockout Techniques; D055993:Germ Cells, Plant / Q000254:growth & development*; D008274:Magnesium / Q000378:metabolism*; D012098:Reproduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C546145:MGT5 protein, Arabidopsis; D008274:Magnesium
keywords: Arabidopsis; Magnesium Transporter 5; male sterile; pollen wall; tapetum