Magnesium transporter AtMGT9 is essential for pollen development in Arabidopsis  

作　　者：Jian Chen Le-gong Li Zhen-hua Liu Yu-ju Yuan Li-lin Guo Dan-dan Mao Lian-fu Tian Liang-bi Chen Sheng Luan Dong-ping Li 

机构地区：[1]College of Life Science, Hunan Normal University, Changsha 410081, China [2]College of Life Science, Capital Normal University, Beijing 100037, China [3]Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA

出　　处：《Cell Research》2009年第7期887-898,共12页细胞研究（英文版）

基　　金：Acknowledgments We are grateful to Dr Michael E Maguire （Case Western Reserve University, USA） for providing the Salmonella mutant strain MM281 and advice on tracer uptake. This work was supported by grants from National Natural Science Foundation of China （30370794）, Hunan Young Scientist Program （03JJY1003）, and Hunan Provincial NSFC （08JJ3088）.

摘　　要：Magnesium （Mg^2＋） is abundant in plant cells and plays a critical role in many physiological processes. A 10-member gene family AtMGT （also known as AtMRS2） was identified in Arabidopsis, which belongs to a eukaryote subset of the CorA superfamily, functioning as Mg^2＋ transporters. Some family members （AtMGT1 and AtMGT10） function as high-affinity Mg^2＋ transporter and could complement bacterial mutant or yeast mutant lacking Mg^2＋ transport capability. Here we report an AtMGT family member, AtMGT9, that functions as a low-affinity Mg^2＋ transporter, and is essential for pollen development. The functional complementation assay in Salmonella mutant strain MM281 showed that AtMGT9 is capable of mediating Mg^2＋ uptake in the sub-millimolar range of Mg^2＋. The AtMGT9 gene was expressed most strongly in mature anthers and was also detectable in vascular tissues of the leaves, and in young roots. Disruption of AtMGT9 gene expression resulted in abortion of half of the mature pollen grains in heterozygous mutant ＋/mgt9, and no homozygous mutant plant was obtained in the progeny of selfed ＋/mgt9 plants. Transgenic plants expressing AtMGT9 in these heterozygous plants can recover the pollen phenotype to the wild type. In addition, At- MGT9 RNAi transgenic plants also showed similar abortive pollen phenotype to mutant ＋/mgt9. Together, our results demonstrate that AtMGT9 functions as a low-affinity Mg^2＋ transporter that plays a crucial role in male gametophyte development and male fertility.

关 键 词：Arabidopsis thaliana AtMGT9 Mg^2＋ transporter pollen grain 

分 类 号：S511[农业科学—作物学] Q943[生物学—植物学]