Science: Newly identified corn variety uses bacteria to up nitrogen intake

September 06, 2018

Sometimes when we hear the word “bacteria,” our minds jump to “germs that can make us sick.” Bacteria can be beneficial, though. One examples: Researchers have identified a type of corn that uses bacteria to grow bigger and stronger in an unconventional way.

The newly identified corn variety, which comes from Oaxaca, Mexico, feeds its sugars to beneficial bacteria, which return nitrogen to the plant in a usable form. Nitrogen is essential for plants — for one, it’s a major component of chlorophyll, which allows plants to use sunlight to produce sugar in the photosynthesis process.

Depending on rainfall and moisture levels, the Oaxacan corn variety can receive 29% to 82% of its nitrogen from the air, researchers that have been studying it say. The plant does this by emitting a sugary, gel-like fluid from its aerial roots (a set of roots that support the plant near the base of its stalk). The fluid attracts bacteria, which take nitrogen from the air and transfer it to the plant. The process is similar to one already known to exist in legumes, and the researchers were even able to imitate it in the lab with a gel they created.

The recently published study outlining the Oaxacan corn is a long time coming. The corn was first observed in the 1980s in a joint effort between researchers and local farmers, who had been growing the corn for generations in the relatively nitrogen-poor soil of the Sierre Mixe region. Continued research was aided in the past decade by new metagenomics technology that allowed researchers to get a better, DNA-level picture of the corn.

The corn itself is interesting as well, standing at over 16 feet tall with multiple sets of aerial roots that don’t even touch the ground. The world’s tallest corn also originates from this part of southern Mexico, where corn was first cultivated by humans thousands of years ago.

The researchers hope that understanding the nitrogen-bacteria trait will allow it to be bred into other varieties of corn. This could increase corn production in areas with nitrogen-poor soil, and even reduce dependency on eco-unfriendly artificial fertilizers.

“This corn showed us that nature can find solutions to some problems far beyond what scientists could ever imagine,” said co-author on the study, Jean-Michel Ané.

Category: Agriculture