植物对病原微生物的“化学防御”:植保素的生物合成及其分子调控机制

The “chemical defense” of plants against pathogenic microbes: Phytoalexins biosynthesis and molecular regulations

植物可以合成大量的次生代谢物来调控自身对环境的适应性。其中,有一大部分直接参与了植物对病原微生物的防御反应,包括植物在感病前就已经生成和积累的植物毒素,以及感病后才从头合成的抗病小分子次生代谢物—植保素。植保素在植物抵御病原菌,特别是腐生性病原菌的过程中起着非常重要的作用。自从80年前植保素的概念被提出后,大量的植保素从各种植物中被分离和鉴定出来,但它们之中大部分的生物合成和调控机制目前尚不清楚。本文综述了近几年来拟南芥和烟草中植保素的研究进展,特别是它们的生物合成及分子调控机制,并对植保素研究领域存在的问题和今后的研究方向进行了讨论和展望。

Plants can produce diverse groups of secondary metabolites to adapt to environment.Many secondary metabolites are involved in the defense responses against pathogenic microbes,including phytoanticipins which are low molecular weight anti-microbial compounds presented in plants before infection,and phytoalexins produced by plants de novo in response to pathogen attack.Phytoalexins are an important part of plant defense repertoire to pathogenic microbes,especially to necrotrophs.Since the concept of phytoalexin was proposed 80 years ago,many kinds of phytoalexins were identified.In contrast,the biosynthesis of most phytoalexins and their regulatory networks are largely unknown.In this review,I summarized recent research progress of phytoalexins in Arabidopsis and Nicotiana species,with special focus on molecular regulations of their biosynthesis.The problems and future directions in phytoalexin research were also discussed.