O-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 sucrose uncoupled1 (sun1) in Arabidopsis (Arabidopsis thaliana). SUN1 encodes a member of the TRICHOME BIREFRINGEN-LIKE family, AtTBL37. AtTBL37 is highly expressed in fast-growing plant tissues and encodes a Golgi apparatus-localized protein that regulates secondary cell wall thickening and acetylation. In sun1, jasmonate signaling and expression of downstream chemical defense genes, including VEGETATIVE STORAGE PROTEIN1 and BRANCHED-CHAIN AMINOTRANSFERASE4, are increased but, unexpectedly, sun1 is more susceptible to insect feeding. The central transcription factor in jasmonate signaling, MYC2, binds to and induces AtTBL37 expression. MYC2 also promotes the expression of many other TBLs. Moreover, MYC activity enhances cell wall acetylation. Overexpression of AtTBL37 in the myc2-2 background reduces herbivore feeding. Our study highlights the role of O-acetylation in controlling plant cell wall properties, plant development, and herbivore defense.

多糖的O-乙酰化主要通过改变理化性质来修饰植物细胞壁，从而改变细胞壁的结构和功能。细胞壁乙酰化酶的表达调节和特定功能仍有待充分了解。在本报告中，我们在拟南芥（Arabidopsis thaliana ）中克隆了一个先前鉴定的生长迟缓突变体，名为蔗糖解偶联1（sun1 ） 。SUN1编码TRICHOME BIREFRINGEN-LIKE家族的成员AtTBL37。AtTBL37在快速生长的植物组织中高度表达，并编码一种调节次生细胞壁增厚和乙酰化的高尔基体定位蛋白。在sun1中，茉莉酸信号传导和下游化学防御基因（包括植物储存蛋白 1和支链氨基转移酶 4）的表达增加，但出乎意料的是，sun1更容易受到昆虫的摄食。茉莉酸信号转导中的核心转录因子 MYC2 结合并诱导AtTBL37表达。MYC2 还促进许多其他TBL的表达。此外，MYC 活性增强细胞壁乙酰化。myc2-2背景中AtTBL37的过度表达会减少食草动物的摄食。我们的研究强调了O-乙酰化在控制植物细胞壁特性、植物发育和食草动物防御中的作用。