WEST LAFAYETTE, Ind. - Purdue University scientists have mapped the entire pathway plants use to create benzoic acid, a precursor to a number of important compounds.
Natalia Dudareva, Distinguished Professor of Horticulture, said plants use benzoic acid to create defensive compounds and growth regulators, and to attract pollinators. Drugs, such as the anticancer medication Taxol, also require benzoic acid for formation. The plants make benzoic acid by modifying the chemical structure of cinnamic acid the same way many organisms break down fatty acids.
"There's a lot of potential. It opens the door to allow scientists to engineer plants for increased benzoic acid production," said Purdue postdoctoral researcher Joshua Widhalm, one of the authors of the findings. "If you want to modify the amount of compounds that attract pollinators, or improve plant defense, it would be important to understand this pathway."
Dudareva, Widhalm and former Purdue postdoctoral researcher Anthony Qualley published their results in the Proceedings of the National Academy of Sciences. They used petunias as a model.
"This completes our understanding of the steps required to create benzoic acid," Dudareva said. "Now, we can put it in textbooks."
The chemical structure of cinnamic acid is a ring with a three-carbon chain coming off the side. The findings show that four enzymes work to remove two of those carbon molecules, resulting in benzoic acid.
Dudareva said when she saw the complete puzzle, she realized that the process for creating benzoic acid will be quite familiar to some scientists.
"In plants and animals, the process already exists in fatty acid oxidation," Dudareva said. "In that process, you break off two carbon units in the acids. This is the same."
Widhalm said the finding showed the ability of plants to take a common process and adapt it for their survival.
"Plants have taken it a step further by using this existing process to create beneficial compounds," Widhalm said. "There is a finite number of chemistries that can occur in plants, and they find combinations of these chemistries to make different products."
The National Science Foundation funded the research. Funmilayo Adebesin and Christine Kish of Purdue collaborated on the study.