Vervaet Lore, De Graeve Femke, Vandenhole Marilou, Vangansbeke Dominiek, Duarte Marcus V A, Lanoo Emma, De Beule Isolde, Wäckers Felix, De Clercq Patrick, Van Leeuwen Thomas
Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent, 9000, Belgium.
Biobest Group N.V., Isle Velden 18, 2260, Westerlo, Belgium.
Insect Biochem Mol Biol. 2025 Aug;182:104350. doi: 10.1016/j.ibmb.2025.104350. Epub 2025 Jun 21.
Tomato production is persistently challenged by pests such as the tomato russet mite (Aculops lycopersici) and pathogens like tomato powdery mildew (Oidium neolycopersici). Traditionally managed with chemical pesticides, sustainable alternatives are needed. This study evaluates the dual role of the omnivorous predatory mite, Pronematus ubiquitus, in directly suppressing pest populations and pathogen infection and indirectly inducing plant defense responses in tomato. Laboratory and greenhouse experiments were conducted using the standard cultivar Castlemart and its jasmonate-deficient mutant, defenseless-1 (def-1), to disentangle the contributions of direct predation from plant-mediated defenses. Pre-exposure of tomato plants to P. ubiquitus significantly reduced A. lycopersici oviposition on Castlemart but not on def-1 plants, implicating jasmonic acid (JA)-dependent defenses in mediating this effect. In vitro assays further demonstrated that P. ubiquitus feeding delayed spore germination and slowed down the development of powdery mildew. Under greenhouse conditions, prolonged exposure to high densities of P. ubiquitus resulted in a marked reduction in powdery mildew incidence compared to both untreated controls and plants treated with the established defense inducer, Macrolophus pygmaeus. Transcriptomic analyses revealed that infestation by P. ubiquitus triggered extensive reprogramming of defense-related gene expression, including the upregulation of key components involved in JA, salicylic acid, and ethylene signaling pathways, as well as genes associated with secondary metabolite biosynthesis and pathogen recognition. Collectively, these findings demonstrate that P. ubiquitus confers enhanced protection against both A. lycopersici and O. neolycopersici through a combination of direct predation and the elicitation of multifaceted plant defenses, offering promising implications for sustainable pest management in tomato cultivation.
番茄生产一直受到番茄锈螨（Aculops lycopersici）等害虫以及番茄白粉病（Oidium neolycopersici）等病原体的挑战。传统上使用化学农药进行管理，因此需要可持续的替代方法。本研究评估了多食性捕食螨普氏钝绥螨（Pronematus ubiquitus）在直接抑制害虫种群和病原体感染以及间接诱导番茄植株防御反应方面的双重作用。使用标准品种卡斯尔马特（Castlemart）及其茉莉酸缺陷型突变体defenseless-1（def-1）进行了实验室和温室实验，以区分直接捕食与植物介导防御的贡献。番茄植株预先接触普氏钝绥螨可显著减少锈螨在卡斯尔马特上的产卵，但对def-1植株无效，这表明茉莉酸（JA）依赖性防御介导了这种效应。体外试验进一步证明，普氏钝绥螨取食会延迟孢子萌发并减缓白粉病的发展。在温室条件下，与未处理的对照植株和用既定防御诱导剂矮小侧多食跗线螨（Macrolophus pygmaeus）处理的植株相比，长时间暴露于高密度的普氏钝绥螨会导致白粉病发病率显著降低。转录组分析表明，普氏钝绥螨侵染引发了防御相关基因表达的广泛重编程，包括JA、水杨酸和乙烯信号通路关键组分的上调，以及与次生代谢物生物合成和病原体识别相关的基因。总的来说，这些发现表明，普氏钝绥螨通过直接捕食和引发多方面的植物防御相结合，增强了对番茄锈螨和番茄新小穴壳菌的保护，为番茄种植中的可持续害虫管理提供了有希望的启示。
