Researchers in California and Ontario have genetically engineered a variety of tomato to grow in salty water, with the goal of getting plants that can grow in soils made salty by irrigation, according to a story in the July 31 Washington Post. The researchers used a gene from the mustard plant called Arabidopsis thaliana, a small plant that is the major model organism of plant research. The tomato variety can store salt in cells in the plant's leaves. The one added protein pumps sodium ions from the cell's fluid into a sac called a vacuole. The levels of sodium and chloride in the fruit itself is reported to be only slightly higher than normal. The new salt-tolerant tomato is not on the market and faces another three years of regulatory reviews and field tests, according to the Post article. Commentary: The Post article notes that plant breeders have long been working on developing salt-tolerant varieties of crops. The review process for this biotech variety will probably have to include an assessment of the possibility of the tomatoes growing as weeds in the wild, especially in salty soils or near estuaries. This will be a new regulatory wrinkle because such tests are not required of new salt-tolerant varieties developed using other methods of genetic manipulation. http://www.nature.com/nbt/press_release/nbt0801.html