Scientists redefine aluminum problem in plants

Researchers at the University of California at Riverside have found a way to increase a plant’s tolerance for aluminum. The work could boost crop yields in acidic soil, a problem affecting more than half of the world’s arable land.

Aluminum halts root growth in acidic soil, which limits crop production in several parts of the world, particularly Africa, South America and South and Southeast Asia.

Scientists thought that the metal directly inhibited the growth of plant cells, but researchers led by biochemist Paul Larsen disproved that notion.

Using Arabidopsis, a small flowering plant belonging to the mustard family, Larsen and his team identified a plant gene called AtATR that acts as a sensor; if there’s too much aluminum in the soil, the AtATR sensor tells the plant to stop growing.

Larsen and his team found a way to tinker with AtATR so that it can tolerate more aluminum. In this way, plants can thrive in what is normally considered aluminum-toxic soil.

The researchers plan to see if the AtATR mutation can be induced in crops such as tomato and corn.

The U.S. Department of Agriculture has been funding research projects that focus on countering aluminum toxicity in acidic soils. In one project, researchers at New York’s Cornell University have been developing aluminum-tolerant sorghum crops.

In another project, American and Brazilian researchers from the University of Florida, the Federal University of Rio Grande do Sul, and Federal University of Rio Grande do Norte in Brazil are studying how crops such as cowpeas and black oats could be used to reduce the effects of aluminum in acidic soils.

Larsen and his team think the aluminum sensor was developed to prevent damaged DNA in affected plants from being passed on to future generations of plants.

The work appears in this week’s issue of Current Biology.