A putative plasma membrane cation/proton antiporter from soybean confers salt tolerance in Arabidopsis.
Cation transport is thought to be an important process for ion homeostasis in plant cells. Here, we report that a soybean putative cation/proton antiporter GmCAX1 may be a mediator of this process. GmCAX1 is expressed in all tissues of the soybean plants but at a lower level in roots. Its expression was induced by PEG, ABA, Ca(2+), Na(+) and Li(+) treatments. The GmCAX1-GFP fusion protein was mainly localized in plasma membrane of the transgenic Arabidopsis plant cells and onion epidermal cells. Transgenic Arabidopsis plants overexpressing GmCAX1 accumulated less Na(+), K(+), and Li(+), and were more tolerant to elevated Li(+) and Na(+) levels during germination when compared with the controls. These results suggest that GmCAX1 may function as an antiporter for Na(+), K(+) and Li(+). Modulation of this antiporter may be beneficial for regulation of ion homeostasis and thus plant salt tolerance.
Luo
Guang-Zuo
GZ
National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, China.
Wang
Hui-Wen
HW
Huang
Jian
J
Tian
Ai-Guo
AG
Wang
Yong-Jun
YJ
Zhang
Jin-Song
JS
Chen
Shou-Yi
SY
D000595:Amino Acid Sequence; D017920:Antiporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008094:Lithium / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology*; D013025:Glycine max / Q000235:genetics*
D017920:Antiporters; D002135:Calcium-Binding Proteins; D027682:Cation Transport Proteins; D010940:Plant Proteins; C027614:calcium-hydrogen antiporters; D012965:Sodium Chloride; D008094:Lithium