白条素研究进展

Advances in albicidin

摘要:

白条黄单胞菌((Xanthomonas albilineans(Ashby) Downson))是我国进境植物检疫性有害生物，其引起的甘蔗白条病是甘蔗上最重要的细菌病害。白条黄单胞菌产生一种高效的植物毒素/抗生素，称为白条素(Albicidin)。作为引起甘蔗白条病的致病因子，白条素通过抑制质体DNA回旋酶阻碍叶绿体分化，导致叶面出现典型的白色条纹症状，同时白条素的抗菌活性也赋予白条黄单胞菌在其定殖甘蔗过程中对抗其他细菌的竞争优势。此外，在纳摩尔浓度下，白条素对人类各种革兰氏阳性和革兰氏阴性病原细菌具有快速杀菌作用，使其成为具有潜在临床应用价值的抗菌药物。文中综述了该毒素的分子结构、传统提取方法、作用机制、生物合成基因及途径和化学合成方法及改良现状，以期为甘蔗白条病的防治及医用新型抗菌素的开发提供参考。

Abstract:

Xanthomonas albilineans (Ashby) Downson is a quarantine pest for importing plants to China that causes leaf scald bacterial disease on sugarcane. X. albilineans produces a potent phytotoxin/antibiotic called albicidin. As a pathogenic factor, albicidin causes typical white leaf stripes by inhibiting plastid DNA gyrase and disturbing chloroplast differentiation. Meanwhile, the antibacterial activity of albicidin gives X. albilineans a competitive advantage against rival bacteria during their colonization. Furthermore, albicidin has a rapid bactericidal activity against a variety of Gram-positive and Gram-negative pathogenic bacteria of human species at nanomolar concentrations, making it a potential antimicrobial drug for clinical application. This article reviews the advances of albicidin from the aspects of its molecular structure, traditional extraction methods, mechanism of action, biosynthetic genes and processes, chemical synthesis method and improvement, in order to provide insights into the prevention and treatment of the sugarcane leaf scald disease, and the development of new antibiotics.