MYC2-Activated Acetylates Cell Walls and Enhances Herbivore Resistance.

-Acetylation of polysaccharides predominantly modifies plant cell walls by changing the physicochemical properties and, consequently, the structure and function of the cell wall. Expression regulation and specific function of cell wall-acetylating enzymes remain to be fully understood. In this report, we cloned a previously identified stunted growth mutant named () in Arabidopsis (). encodes a member of the family, is highly expressed in fast-growing plant tissues and encodes a Golgi apparatus-localized protein that regulates secondary cell wall thickening and acetylation. In , jasmonate signaling and expression of downstream chemical defense genes, including and , are increased but, unexpectedly, is more susceptible to insect feeding. The central transcription factor in jasmonate signaling, MYC2, binds to and induces expression. MYC2 also promotes the expression of many other Moreover, MYC activity enhances cell wall acetylation. Overexpression of in the background reduces herbivore feeding. Our study highlights the role of acetylation in controlling plant cell wall properties, plant development, and herbivore defense.