Higuera José Javier, Garrido-Gala José, Lekhbou Ayman, Arjona-Girona Isabel, Amil-Ruiz Francisco, Mercado José A, Pliego-Alfaro Fernando, Muñoz-Blanco Juan, López-Herrera Carlos J, Caballero José L
Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba, Spain.
Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible (CSIC), Córdoba, Spain.
Front Plant Sci. 2019 Apr 18;10:480. doi: 10.3389/fpls.2019.00480. eCollection 2019.
Strawberry ( ×) is a major food crop worldwide, due to the flavor, aroma and health benefits of the fruit, but its productivity and quality are seriously limited by a large variety of phytopathogens, including spp. So far, key factors regulating strawberry immune response remain unknown. The gene has been previously proposed as an important element mediating defense responses in strawberry to . To get further insight into the functional role that FaWRKY1 plays in the defense mechanism, -mediated transient transformation was used both to silence and overexpress the gene in strawberry fruits ( × cv. Primoris), which were later analyzed upon inoculation. Susceptibility tests were performed after pathogen infection comparing the severity of disease between the two agroinfiltrated opposite halves of the same fruit, one half bearing a construct either for overexpression or RNAi-mediated silencing and the other half bearing the empty vector, as control. The severity of tissue damage was monitored and found to be visibly reduced at five days after pathogen inoculation in the fruit half where was transiently silenced compared to that of the opposite control half and statistical analysis corroborated a significant reduction in disease susceptibility. Contrarily, a similar level of susceptibility was found when overexpression and control fruit samples, was compared. These results unravel a negative regulatory role of FaWRKY1 in resistance to the phytopathogenic fungus in strawberry fruit and contrast with the previous role described for this gene in as positive regulator of resistance against the bacteria . Based on previous results, a tentative working model for WRKY75 like genes after pathogen infection is proposed and the expression pattern of potential downstream FaWRKY1 target genes was also analyzed in strawberry fruit upon infection. Our results highlight that FaWRKY1 might display different function according to species, plant tissue and/or type of pathogen and underline the intricate FaWRKY1 responsive defense regulatory mechanism taking place in strawberry against this important crop pathogen.
草莓（×）是全球主要的粮食作物，因其果实的风味、香气和健康益处而闻名，但它的生产力和品质受到多种植物病原体的严重限制，包括 spp.。到目前为止，调节草莓免疫反应的关键因素仍然未知。先前已提出 基因是介导草莓对 的防御反应的重要元件。为了进一步深入了解 FaWRKY1 在防御机制中的功能作用，利用 -介导的瞬时转化在草莓果实（× cv. Primoris）中沉默和过表达 基因，随后在接种 后进行分析。在病原体感染后进行易感性测试，比较同一果实的两个经农杆菌浸润的相对半侧之间的疾病严重程度，其中一半携带用于 过表达或 RNAi 介导沉默的构建体，另一半携带空载体作为对照。监测组织损伤的严重程度，发现在病原体接种五天后，与相对的对照半侧相比，在 被瞬时沉默的果实半侧，组织损伤明显减少，统计分析证实疾病易感性显著降低。相反，当比较 过表达和对照果实样品时，发现易感性水平相似。这些结果揭示了 FaWRKY1 在草莓果实对植物病原真菌 的抗性中起负调节作用，这与先前描述的该基因在 中作为抗细菌 的抗性正调节因子的作用形成对比。基于先前的结果，提出了病原体感染后 WRKY75 样基因的初步工作模型，并在草莓果实感染 后分析了潜在下游 FaWRKY1 靶基因的表达模式。我们的结果强调，FaWRKY1 可能根据物种、植物组织和/或病原体类型表现出不同的功能，并强调了在草莓中针对这种重要作物病原体发生的复杂的 FaWRKY1 响应防御调节机制。
