When a plant goes into defense mode in order to protect itself against harsh weather or disease, that’s good for the plant, but bad for the farmer growing the plant. Bad because when a plant acts to defend itself, it turns off its growth mechanism.

But now researchers at Michigan State University, as part of an international collaboration, have figured out how plants can make the “decision” between growth and defense, a finding that could help them strike a balance – keep safe from harm while continuing to grow.

Sheng Yang He, a professor of plant biology, and his team found that the two hormones that control growth (called gibberellins) and defense (known as jasmonates) literally come together in a crisis and figure out what to do.

“What we’ve discovered is that some key components of growth and defense programs physically interact with each other,” he says. “Communication between the two is how plants coordinate the two different situations.

“We now know where one of the elusive molecular links is between growth and defense.”

This is important because now that scientists know that this happens, they can work to figure out how to “uncouple” the two, he adds.

“Perhaps at some point we can genetically or chemically engineer the plants so they don’t talk to each other that much,” he says. “This way we may be able to increase yield and defense at the same time.

“Plants, like people, have to learn to prioritize,” he says. “You can use your energy for growth, or use it for defense, but you can’t do them both at maximum level at the same time.”

The work was done on two different plants: rice, a narrow-leafed plant, and Arabidopsis, which has a broader leaf. This was significant because it demonstrated that this phenomenon occurs in a variety of plants.