A chemical elicitor, 4- fluorophenoxyacetic acid suppresses insect pest populations and increases crop yields (PNAS)

Plant strengtheners, synthetic chemical elicitors, have been shown to enhance plant resistance against various insect pests without toxic effects on the environment, but evidence is lacking for a significant increase in crop growth and yield after using these elicitors. To address this, Wang et al. studied 4-fluorophenoxyacetic acid (4-FPA), which in rice fields infested with white-backed planthopper led to a reduction in the insects’ survival rate. Treatment with 4-FPA induces production of peroxidases, hydrogen peroxide, and flavonoids. Additionally, deposition of flavonoid polymers in the parenchyma cells of the leaf sheath inhibits the plant hopper’s stylet from reaching the phloem sap. Greenhouse and field tests on growth and yield of rice after 4-FDA treatment showed growth recovery and significantly higher yield compared to control plants. Studies of 4-FDA in other cereals showed broad-spectrum resistance to piercing-sucking insect pests. In conclusion, this study showed 4-FDA as a promising chemical elicitor in controlling piercing and sucking insect pests.  (Summary by Sunita Pathak @psunita980 ) Proc. Natl. Acad. Sci. USA 10.1073/pnas.2003742117