Uncovering pathways toward engineering pest resistance

Michigan State University scientists are examining the biochemistry of plants in research that could lead to advancements in the production of plants that are less susceptible to insect pests.

"Plants are master biochemists," said Robert Last, MSU Barnett Rosenberg Professor of Biochemistry and Molecular Biology and Plant Biology, and director of the lab where this research is being conducted. "They are great at making metabolites that protect the plants from the environment. Humans are beneficiaries because some of these products are potent medicines or make our foods more tasty and nutritious."

In Last's lab, postdoctoral scholar

Pengxiang Fan and undergraduate biochemistry and molecular biology student Abigail Miller were able to reconstruct the pathway of chemical processes that a tomato plant uses to create useful compounds. The particular compounds they studied, called acyl sugars, are made in both the garden variety and wild relatives of tomato plants. The researchers examined how a single cell in the tip of tiny hairs on these plants ─ called trichomes ─ are able to create products that protect them from being eaten by insects.

"These cells are little self-contained factories," Last said. "Understanding this pathway could also allow us to come up with strategies to make these kind of useful compounds in microorganisms or in other plants that don't normally make them."

The potential of the research is wide-ranging, with possible future applications in plant breeding, safe pesticides and other industries.

"We might be able to engineer resistance to pests by modifying this pathway. In theory we could get these pathways operating in microorganisms to make industrially useful compounds," Last said. "These types of compounds could even be used for biofuels."

The research is presented in a paper published in the current issue of Proceedings of the National Academy of Sciences.

"This paper demonstrates that we know the whole pathway that these tiny cells use to take simple molecules like table sugar and turn them into commercially useful products," Last said. "It allows us to see what really happens in the tomato plant. It's simple in concept and therefore quite elegant."

Last's lab collaborated with the lab of Daniel Jones in the Department of Biochemistry and Molecular Biology at MSU, as well as the group of Dani Zamir at the Hebrew University of Jerusalem.