A mitochondrial magnesium transporter functions in Arabidopsis pollen development.
Magnesium is an abundant divalent cation in plant cells and plays a critical role in many physiological processes. We have previously described the identification of a 10-member Arabidopsis gene family encoding putative magnesium transport (MGT) proteins. Here, we report that a member of the MGT family, AtMGT5, functions as a dual-functional Mg-transporter that operates in a concentration-dependent manner, namely it serves as a Mg-importer at micromolar levels and facilitates the efflux in the millimolar range. The AtMGT5 protein is localized in the mitochondria, suggesting that AtMGT5 mediates Mg-trafficking between the cytosol and mitochondria. The AtMGT5 gene was exclusively expressed in anthers at early stages of flower development. Examination of two independent T-DNA insertional mutants of AtMGT5 gene demonstrated that AtMGT5 played an essential role for pollen development and male fertility. This study suggests a critical role for Mg(2+) transport between cytosol and mitochondria in male gametogenesis in plants.
Li
Le-Gong
LG
College of Life Sciences, Capital Normal University, Beijing 100037, China.
Sokolov
Lubomir N
LN
Yang
Yong-Hua
YH
Li
Dong-Ping
DP
Ting
Julie
J
Pandy
Girdhar K
GK
Luan
Sheng
S
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008274:Magnesium / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D009532:Nickel / Q000378:metabolism; D009928:Organ Specificity; D010641:Phenotype; D011058:Pollen / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D021381:Protein Transport
D029681:Arabidopsis Proteins; C546145:MGT5 protein, Arabidopsis; D026901:Membrane Transport Proteins; D009532:Nickel; D008274:Magnesium