How corn plants defend against pathogen attack

Researchers from the North Carolina State University have identified crucial genes and cellular processes that appear to control the so-called hyper-sensitive defence response (HR) in corn.

The findings could help researchers build better defence responses in corn and other plants.

"It is similar to a human having an auto-immune response that never stops," said Peter Balint-Kurti, a professor from the department of plant pathology and crop science at the North Carolina State University.

When corn plants come under attack from a pathogen, they sometimes respond by killing their own cells near the site of the attack, committing "cell suicide" to thwart further damage from the attacker.

It has so far been difficult to understand how the plant regulates this defence mechanism because the response is so quick and localised.

During the study, researchers examined over 3,300 maize plants that contained a similar mutation.

They found that 44 candidate genes appear to be involved in defence response and a few other responses linked to resisting attack.

"This mutation causes a corn plant to inappropriately trigger this hyper-sensitive defence response, causing spots on the corn plant as well as stunted growth," added Balint-Kurti.

The researchers examined the entire corn gene blueprint to find the genes most closely associated with HR.

"Hopefully this work provides an opening to really characterise this important defence response and learn more about it in other plants," Balint-Kurti concluded.

The study appeared in the journal PLoS Genetics.