Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
Ecol Lett. 2012 Dec;15(12):1430-8. doi: 10.1111/ele.12001. Epub 2012 Sep 19.
Pathogens can alter host phenotypes in ways that influence interactions between hosts and other organisms, including insect disease vectors. Such effects have implications for pathogen transmission, as well as host exposure to secondary pathogens, but are not well studied in natural systems, particularly for plant pathogens. Here, we report that the beetle-transmitted bacterial pathogen Erwinia tracheiphila - which causes a fatal wilt disease - alters the foliar and floral volatile emissions of its host (wild gourd, Cucurbita pepo ssp. texana) in ways that enhance both vector recruitment to infected plants and subsequent dispersal to healthy plants. Moreover, infection by Zucchini yellow mosaic virus (ZYMV), which also occurs at our study sites, reduces floral volatile emissions in a manner that discourages beetle recruitment and therefore likely reduces the exposure of virus-infected plants to the lethal bacterial pathogen - a finding consistent with our previous observation of dramatically reduced wilt disease incidence in ZYMV-infected plants.
病原体可以改变宿主表型，从而影响宿主与其他生物（包括昆虫病媒）之间的相互作用。这些影响与病原体的传播以及宿主接触次生病原体有关，但在自然系统中研究得还不够充分，特别是对于植物病原体。在这里，我们报告说，由甲虫传播的细菌病原体 Erwinia tracheiphila - 它会导致致命的萎蔫病 - 改变了其宿主（野生葫芦，Cucurbita pepo ssp.texana）的叶片和花朵挥发性排放物，以增强对感染植物的病媒招募和随后向健康植物的传播。此外，在我们的研究地点也发生的南瓜黄花叶病毒（ZYMV）的感染以一种阻止甲虫招募的方式减少了花朵挥发性排放物，因此可能会降低感染病毒的植物接触致命细菌病原体的机会 - 这一发现与我们之前观察到的 ZYMV 感染植物萎蔫病发病率显著降低的结果一致。
