Phenotypic changes in Arabidopsis caused by expression of a yeast vacuolar Ca2+/H+ antiporter.
In plants, cytosolic Ca2+ levels are tightly regulated, and changes in cytosolic Ca2+ have been implicated in converting numerous signals into adapted responses. Vacuolar ion transporters are thought to be key mediators of cytosolic Ca2+ concentrations. In an attempt to interpret the role of vacuolar Ca2+ transport in plant processes, we have expressed the yeast vacuolar Ca2+/H+ antiporter, VCX1, in Arabidopsis and tobacco. This transporter localizes to the plant vacuolar membrane. VCX1-expressing Arabidopsis plants displayed increased sensitivity to sodium and other ions. These ion sensitivities could be suppressed by addition of calcium to the media. VCX1-expressing plants demonstrated increased tonoplast-enriched Ca2+/H+ antiport activity as well as increased Ca2+ accumulation. These results suggest that VCX1 expression in Arabidopsis could be a valuable tool with which to experimentally dissect the role of Ca2+ transport around the plant vacuole.
Hirschi
K D
KD
Baylor College of Medicine, Plant Physiology Group, U.S. Department of Agriculture, Agricultural Research Service, Children's Nutrition Research Center, Houston, TX 77030, USA. kendalh@bcm.tmc.edu
Miranda
M L
ML
Wilganowski
N L
NL
D017920:Antiporters / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins; D005656:Fungal Proteins / Q000235:genetics*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D010641:Phenotype; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D010947:Plants, Toxic; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014026:Nicotiana / Q000235:genetics
D017920:Antiporters; D002135:Calcium-Binding Proteins; D027682:Cation Transport Proteins; D005656:Fungal Proteins; C027614:calcium-hydrogen antiporters; D002118:Calcium