Hoffmann Annika, Lischeid Gunnar, Koch Matthias, Lentzsch Peter, Sommerfeld Thomas, Müller Marina E H
Leibniz Centre for Agricultural Landscape Research (ZALF), 15374 Müncheberg, Germany.
Institute for Horticultural Sciences, Humboldt-Universität zu Berlin, 14195 Berlin, Germany.
Microorganisms. 2021 Feb 20;9(2):443. doi: 10.3390/microorganisms9020443.
Mycotoxigenic fungal pathogens and are a leading cause of loss in cereal production. On wheat-ears, they are confronted by bacterial antagonists such as pseudomonads. Studies on these groups' interactions often neglect the infection process's temporal aspects and the associated priority effects. In the present study, the focus was on how the first colonizer affects the subsequent ones. In a climate chamber experiment, wheat-ears were successively inoculated with two different strains (625, 23, or 9). Over three weeks, microbial abundances and mycotoxin concentrations were analyzed and visualized via Self Organizing Maps with Sammon Mapping (SOM-SM). All three strains revealed different characteristics and strategies to deal with co-inoculation: 23, as the first colonizer, suppressed the establishment of 625 and 9. Nevertheless, primary inoculation of 625 reduced all of the toxins and stopped 9 from establishing. 9 showed priority effects in delaying and blocking the production of the fungal mycotoxins. The SOM-SM analysis visualized the competitive strengths: 23 ranked first, 625 second, 9 third. Our findings of species-specific priority effects in a natural environment and the role of the mycotoxins involved are relevant for developing biocontrol strategies.
产毒真菌病原体是谷物生产损失的主要原因。在麦穗上，它们会遇到诸如假单胞菌等细菌拮抗剂。对这些群体间相互作用的研究往往忽略了感染过程的时间因素以及相关的优先效应。在本研究中，重点是首个定殖者如何影响后续定殖者。在气候箱实验中，麦穗先后接种了两种不同菌株（625、23或9）。在三周时间里，通过带有 Sammon 映射的自组织映射（SOM-SM）分析并可视化了微生物丰度和霉菌毒素浓度。所有三种菌株在应对共接种时都表现出不同的特征和策略：23作为首个定殖者，抑制了625和9的定殖。然而，先接种625降低了所有毒素，并阻止了9的定殖。9在延迟和阻断真菌霉菌毒素产生方面表现出优先效应。SOM-SM分析直观显示了竞争强度：23排名第一，625第二，9第三。我们在自然环境中发现的物种特异性优先效应以及所涉及的霉菌毒素的作用，对于制定生物防治策略具有重要意义。
