The plant pathogen, Pseudomonas syringae (Ps), together with related Ps species, infects and attacks a wide range of agronomically important crops, including tomato, kiwifruit, pepper, olive and soybean, causing economic losses. Currently, chemicals and introduced resistance genes are used to protect plants against these pathogens but have limited success and may have adverse environmental impacts. Consequently, there is a pressing need to develop alternative strategies to combat bacterial disease in crops. One such strategy involves using narrow-spectrum protein antibiotics (so-called bacteriocins), which diverse bacteria use to compete against closely related species. Here, we demonstrate that one bacteriocin, putidacin L1 (PL1), can be expressed in an active form at high levels in Arabidopsis and in Nicotiana benthamiana in planta to provide effective resistance against diverse pathovars of Ps. Furthermore, we find that Ps strains that mutate to acquire tolerance to PL1 lose their O-antigen, exhibit reduced motility and still cannot induce disease symptoms in PL1-transgenic Arabidopsis. Our results provide proof-of-principle that the transgene-mediated expression of a bacteriocin in planta can provide effective disease resistance to bacterial pathogens. Thus, the expression of bacteriocins in crops might offer an effective strategy for managing bacterial disease, in the same way that the genetic modification of crops to express insecticidal proteins has proven to be an extremely successful strategy for pest management. Crucially, nearly all genera of bacteria, including many plant pathogenic species, produce bacteriocins, providing an extensive source of these antimicrobial agents.

中文翻译：

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工程细菌素介导的针对植物病原体丁香假单胞菌的抗性。


植物病原体丁香假单胞菌 (Ps) 与相关的 Ps 物种一起感染并攻击多种重要的农艺作物，包括番茄、猕猴桃、胡椒、橄榄和大豆，造成经济损失。目前，使用化学品和引入的抗性基因来保护植物免受这些病原体的侵害，但效果有限，并且可能对环境产生不利影响。因此，迫切需要开发替代策略来对抗农作物的细菌性疾病。其中一种策略涉及使用窄谱蛋白质抗生素（所谓的细菌素），不同的细菌用它来与密切相关的物种竞争。在这里，我们证明了一种细菌素，恶臭菌素 L1 (PL1)，可以在拟南芥和本氏烟草中以活性形式高水平表达，以提供对多种恶臭霉菌的有效抵抗力。此外，我们发现突变以获得对 PL1 耐受性的 Ps 菌株失去了 O 抗原，表现出运动性降低，并且仍然不能在 PL1 转基因拟南芥中诱导疾病症状。我们的结果提供了原理证明，即转基因介导的细菌素在植物中的表达可以提供对细菌病原体的有效抗病性。因此，在作物中表达细菌素可能为控制细菌性疾病提供一种有效的策略，就像通过基因改造作物来表达杀虫蛋白已被证明是一种极其成功的害虫管理策略一样。至关重要的是，几乎所有细菌属，包括许多植物病原菌种，都会产生细菌素，为这些抗菌剂提供了广泛的来源。