Until the 20th century, this had to be done by breeding desirable characteristics into crops. ... Basically, the sodium ions in salt are toxic to plants because they interfere with their metabolism. The modified tomato contains a gene that makes it gather ions inside vacuoles where they can't harm the plant. ... Environmentalists are worried that GM crops could pollinate wild plant species, introducing foreign GM genes into non-GM species. ...

• Word Count: 807
• Approx Pages: 3
• Grade Level: High School