Plants are surrounded by a diverse range of microorganisms that causes serious crop losses and requires the use of pesticides. Flax is a major crop in Normandy used for its fibres and is regularly challenged by the pathogenic fungus Fusarium oxysporum (Fo) f. sp. lini. To protect themselves, plants use "innate immunity" as a first line of defense level against pathogens. Activation of plant defense with elicitors could be an alternative for crop plant protection. A previous work was conducted by screening a chemical library and led to the identification of compounds able to activate defense responses in Arabidopsis thaliana. Four compounds were tested for their abilities to improve resistance of two flax varieties against Fo. Two of them, one natural (holaphyllamine or HPA) and one synthetic (M4), neither affected flax nor Fo growth. HPA and M4 induced oxidative burst and callose deposition. Furthermore, HPA and M4 caused changes in the expression patterns of defense-related genes coding a glucanase and a chitinase-like. Finally, plants pre-treated with HPA or M4 exhibited a significant decrease in the disease symptoms. Together, these findings demonstrate that HPA and M4 are able to activate defense responses in flax and improve its resistance against Fo infection.

中文翻译：

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鉴定两种能够提高亚麻对尖孢镰刀菌感染的抵抗力的化合物

植物周围有各种各样的微生物，这些微生物会导致严重的作物损失并需要使用杀虫剂。亚麻是诺曼底的一种主要作物，用于生产其纤维，并经常受到致病真菌尖孢镰刀菌 (Fo) f 的攻击。sp. 里尼。为了保护自己，植物使用“先天免疫”作为抵御病原体的第一道防线。用诱导子激活植物防御可能是作物植物保护的替代方案。之前的一项工作是通过筛选化学库进行的，并导致鉴定出能够激活拟南芥防御反应的化合物。测试了四种化合物提高两种亚麻品种对 Fo 的抗性的能力。其中两种，一种是天然的（霍拉酚胺或 HPA），一种是合成的（M4），既不影响亚麻也不影响 Fo 的生长。HPA 和 M4 诱导氧化爆发和胼胝质沉积。此外，HPA 和 M4 导致编码葡聚糖酶和几丁质酶样的防御相关基因的表达模式发生变化。最后，用 HPA 或 M4 预处理的植物表现出疾病症状的显着减少。总之，这些发现表明 HPA 和 M4 能够激活亚麻的防御反应并提高其对 Fo 感染的抵抗力。