The origin and biosynthesis of the naphthalenoid moiety of juglone in black walnut

Abstract

Bioengineering: revealing the genetic roots of a potential natural herbicide Revealing the synthetic pathway of the natural herbicide juglone paves the way for genetically engineered, weed-resistant crops. Juglone, belonging to the same molecular family as phylloquinone (also known as vitamin K1), is produced by plants, including black walnut and is generally toxic to nearby plant life. Until now, the genetic and synthetic basis of juglone remained unknown. Using genetic analysis, a research team from the United States’ Purdue University, led by Joshua Widhalm, discovered that juglone is actually a product of the same synthetic pathway as phylloquinone and shares the same progenitor—a molecule called DHNA. This study partially reveals the genes responsible for juglone synthesis, and the authors suggest that the next step involves elucidating how the chemical is produced from DHNA. This discovery informs future efforts to engineer resilience into important crops.