Along with Hong-Xia Wang, now at the University of Toronto, Blumwald cloned several genes encoding Na+/H+ antiport proteins from Arabidopsis thaliana, a member of the mustard family. Antiports exchange protons, which plants secrete in abundance using a pump powered by photosynthesis, for sodium ions, which end up either outside the cell or inside storage organelles called vacuoles. When Wang and Blumwald inserted one of the genes into tomato plants, antiport activity in isolated leaf vesicles skyrocketed. The plants grew well on 200 mM NaCl and were as large as untransformed controls.
Unfortunately, naturally salty tomatoes aren't in the cards. Sodium levels remained low inside transformed tomato fruits, which were as sweet as wild type tomatoes. Blumwald estimates that by planting transformed canola--a cousin of Arabidopsis that grows at high density--farmers could extract up to 4000 kg of salt per 10,000 square meters of high saline land per year, thus reclaiming ...
