Recent research from the Michigan State University-DOE Plant Research Laboratory shows the connection between two plant defense systems and plant growth and photosynthesis, or how plants convert sunlight to energy.
By understanding how plants evolved over time to learn how to defend themselves, the MSU scientists hope to find ways to help them react to greater stressors in the future. The study, conducted in the labs of Christoph Benning and Gregg Howe, is featured in The Plant Cell.
Kun Wang, a former doctorate student in the lab of Christoph Benning, and his collaborators show how two proteins break down chloroplast lipids to help plants defend against pests and herbivores.
Plants essentially play a version of the children’s game, telephone, Wang explained.
“In the children’s game, the first person whispers a message into the ear of the next person in the line, and so on, until the last player announces the message to the entire group,” he said.
By having a defense system, plants are able to sense environmental threats that would otherwise prevent them from growing.
“The cross-talk between defense systems has a purpose. For example, there is mounting evidence that plants facing drought are more vulnerable to caterpillar attacks,” Wang said. “The chloroplast [where photosynthis takes place in green plant cells] is amazing. For example, its membrane lipids also help with oil production, which is interesting for developing a source for biofuels. We think the chloroplast takes part in other Telephone games leading to different ends we have yet to examine.”
For plants, Wang explains the “chemical cascade” of Telephone as:
- The plant senses non-living threats, like cold or drought, and raises the alarm through the hormone ABA;
- This alarm triggers the two proteins to break down lipids from the chloroplast membrane;
- The lipid products turn into another hormone, which takes part in the insect defense system.
“One can imagine plants evolved precautionary defenses for varied conditions. The ability to talk with each other helps them form a comprehensive defense strategy.” Wang said. “We think the chloroplast takes part in other Telephone games leading to different ends we have yet to examine. Understanding those functions could help us engineer plants to be more resistant to complex stresses.”