Jechalke Sven, Schierstaedt Jasper, Becker Marlies, Flemer Burkhardt, Grosch Rita, Smalla Kornelia, Schikora Adam
Institute for Phytopathology, Justus Liebig University Giessen, Gießen, Germany.
Leibniz Institute of Vegetable and Ornamental Crops, Plant-Microbe Systems, Großbeeren, Germany.
Front Microbiol. 2019 May 15;10:967. doi: 10.3389/fmicb.2019.00967. eCollection 2019.
Human pathogenic bacteria, such as , are able to colonize crop plants. So far, not much is known about biotic and abiotic factors influencing this colonization in field soil. This understanding, however, is imperative for the provision of safe fresh produce to the consumer. In this study, we investigated the effects of soil type, organic fertilization, plant species and the way of entry into the plant production system, on the survival of in soil as well as the colonization of plants. The selected serovar Typhimurium strain 14028s, Typhimurium strain LT2 and Senftenberg were able to persist in soil for several weeks. persistence in soil was prolonged in loamy, if compared to sandy soil, and when applied together with organic fertilizer. The leaves of lettuce and corn salad were colonized by providing evidence for internalization from the soil the root. Colonization rates were affected by soil type, plant species and strain. Overall, was detected in leaves of 0.5-0.9% of the plants, while lettuce was more frequently colonized than corn salad. Plants grown in sandy soil were more often colonized than plants grown in loamy soil. After spray inoculation, could be detected on and in leaves for several weeks by cultivation-depending methods, confirmed by confocal microscopy using GFP-labeled Typhimurium 14028s. On the one hand, transcriptome data from Typhimurium 14028s assessed in response to lettuce medium or lettuce root exudates showed an upregulation of genes associated with biofilm formation and virulence. On the other hand, lettuce inoculated with Typhimurium 14028s showed a strong upregulation of genes associated with plant immune response and genes related to stress response. In summary, these results showed that organic fertilizers can increase the persistence of in soil and that soil type and plant species play a crucial role in the interactions between human pathogens and crop plants. This understanding is therefore a starting point for new strategies to provide safe food for the consumer.
人类病原菌，如，能够在农作物上定殖。到目前为止，关于影响田间土壤中这种定殖的生物和非生物因素，人们了解得还不多。然而，这种认识对于向消费者提供安全的新鲜农产品至关重要。在本研究中，我们调查了土壤类型、有机施肥、植物种类以及进入植物生产系统的方式，对在土壤中的存活以及植物定殖的影响。所选的鼠伤寒血清型14028s菌株、鼠伤寒LT2菌株和森夫滕贝格菌株能够在土壤中持续存在数周。与沙质土壤相比，在壤土中以及与有机肥料一起施用时，在土壤中的持续时间会延长。生菜和玉米沙拉的叶子被定殖，这为从土壤通过根部内化提供了证据。定殖率受土壤类型、植物种类和菌株的影响。总体而言，在0.5 - 0.9%的植物叶子中检测到，而生菜比玉米沙拉更频繁地被定殖。生长在沙质土壤中的植物比生长在壤土中的植物更常被定殖。喷雾接种后，通过依赖培养的方法，在叶子上和叶子中可以检测到数周，使用绿色荧光蛋白标记的鼠伤寒14028s通过共聚焦显微镜得到证实。一方面，针对生菜培养基或生菜根分泌物评估的鼠伤寒14028s的转录组数据显示，与生物膜形成和毒力相关的基因上调。另一方面，接种鼠伤寒14028s的生菜显示出与植物免疫反应相关的基因以及与应激反应相关的基因强烈上调。总之，这些结果表明有机肥料可以增加在土壤中的持续时间，并且土壤类型和植物种类在人类病原体与农作物的相互作用中起着关键作用。因此，这种认识是为消费者提供安全食品的新策略的起点。
