WEST LAFAYETTE, IN, December 17, 2001 - One-third of US agricultural land and 50 percent of the irrigated land area worldwide has salt levels high enough to reduce yields so finding a crop that can grow in these conditions would be a great breakthrough. Leading the charge in this area are Purdue University scientists who have discovered the protein and the gene responsible for allowing salt to enter plants. With this knowledge comes the potential for improved agriculture here in the US and in many parts of the world.

"As long as people have been working on salinity toxicity - over many decades and in thousands of scientific papers written on the subject - no one knew the most fundamental thing about it, which is how sodium gets into plants. We didn't know the beginning of the story," says Ray Bressan, professor of horticulture at Purdue. "So this is the first piece of work that shows what protein is responsible. There have been biochemical experiments that showed that this protein had the potential to be a sodium transporter, but there was no evidence that it was actually involved in tolerance to sodium toxicity in plants."

Salt toxicity comes about as a result of the extensive use of irrigation systems. Irrigation water brings dissolved salts such as sodium, calcium, magnesium, potassium, sulfate, and chloride. When the water is removed from the soil through evaporation and plant uptake, excessive amounts of salts are left behind to accumulate in soils.

In addition to the artificial introduction of salt, some areas, such as in Egypt and Israel, have problems with saline groundwater. Despite decades of plant breeding efforts, researchers have not been able to develop more than a few salt-resistant plants.

"A second reason that this research is important is that we also discovered more about how the protein functions," Bressan says. "We discovered another entry system for sodium. This explains why controlling this entry system didn't allow us to make completely salt-tolerant plants. They're more tolerant, but not completely. But now we have important clues about how this works.

"When we've identified all of the salt-tolerance genes of plants, we'll be able to control them, and we'll be able to create salt-tolerant crops. Now we see the light at the end of the tunnel."