Premium
Magnesium Transporter 5 plays an important role in Mg transport for male gametophyte development in Arabidopsis
Author(s) -
Xu XiaoFeng,
Wang Bo,
Lou Yue,
Han WenJian,
Lu JieYang,
Li DanDan,
Li LeGong,
Zhu Jian,
Yang ZhongNan
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13054
Subject(s) - tapetum , gametophyte , microbiology and biotechnology , biology , immunoelectron microscopy , arabidopsis , locule , stamen , mutant , botany , genetics , microspore , gene , pollen , antibody
Summary During anther development the male gametophyte develops inside the locule and the tapetal cells provide all nutrients for its development. Magnesium Transporter 5 ( MGT 5 ) 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 ‐ MGT 5 revealed that MGT 5 is localized in the plasma membrane. These findings suggest that in the male gametophyte MGT 5 plays a role in importing Mg from the locule and that Mg is essential for male gametophyte development. The expression of MGT 5 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 MGT 5 . An immunoelectron microscopy assay revealed that MGT 5‐His is localized to the plasma membrane of the tapetum. These findings suggest that AMS directly regulates MGT 5 in the tapetum and thus induces export of Mg into the locule. The mgt5 plant exhibits severe male sterility while the expression of MGT 5 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, MGT 5 plays an important role in Mg transport from the tapetum to the microspore.