Holland Cynthia K, Watson Aracely P, Chiang Ellia
Department of Biology, Williams College, Williamstown, MA, United States.
Front Plant Sci. 2025 Jul 8;16:1625337. doi: 10.3389/fpls.2025.1625337. eCollection 2025.
Plants synthesize a diverse array of specialized metabolites that contribute to plant development, growth, protection from biotic and abiotic stressors, and attracting pollinators and seed dispersers. Specialized metabolites are often derived from primary metabolites, such as amino acids, but also can be redirected from intermediates in primary metabolic pathways. In the L-tryptophan (Trp) biosynthetic pathway, the intermediate anthranilate is siphoned away to synthesize volatiles and specialized metabolites. Methyltransferases can produce the methyl ester of anthranilate, a grape aroma volatile produced in species such as grapevine, strawberry, citrus, maize, and soybean. -Methyl anthranilate serves context-dependent roles in attracting insects and deterring herbivores. Methylation at the amine generates -methyl anthranilate, a precursor for -methyl anthranilate esters in citrus and antimicrobial avenacins in black oat. This Mini Review explores the regulation of anthranilate within the context of the Trp pathway and its contributions to the biosynthesis of anthranilate-containing volatiles and specialized metabolites. Also highlighted are the roles of anthranilates in plant defensive metabolism and the substrate specificity of anthranilate-using enzymes, as well as unanswered questions about the synthesis, transport, and physiological role of anthranilates.
植物合成多种特殊代谢产物，这些产物有助于植物的发育、生长、抵御生物和非生物胁迫，以及吸引传粉者和种子传播者。特殊代谢产物通常源自初级代谢产物，如氨基酸，但也可以从初级代谢途径的中间产物重新定向而来。在L-色氨酸（Trp）生物合成途径中，中间产物邻氨基苯甲酸被分流以合成挥发性物质和特殊代谢产物。甲基转移酶可以产生邻氨基苯甲酸甲酯，这是一种在葡萄、草莓、柑橘、玉米和大豆等物种中产生的葡萄香气挥发性物质。邻氨基苯甲酸甲酯在吸引昆虫和威慑食草动物方面发挥着依赖于环境的作用。胺基上的甲基化产生N-甲基邻氨基苯甲酸，它是柑橘中N-甲基邻氨基苯甲酸酯和黑燕麦中抗菌燕麦素的前体。本综述探讨了邻氨基苯甲酸在Trp途径中的调控及其对含邻氨基苯甲酸挥发性物质和特殊代谢产物生物合成的贡献。还强调了邻氨基苯甲酸在植物防御代谢中的作用以及使用邻氨基苯甲酸的酶的底物特异性，以及关于邻氨基苯甲酸的合成、运输和生理作用的未解决问题。
