Tao Siqi, Zhang Yunxia, Tian Chengming, Duplessis Sébastien, Zhang Naili
The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China.
Université de Lorraine, INRAE, IAM, 54000 Nancy, France.
J Fungi (Basel). 2022 May 18;8(5):523. doi: 10.3390/jof8050523.
Tropospheric ozone and nitrogen deposition are two major environmental pollutants. A great deal of research has focused on the negative impacts of elevated O and the complementary effect of soil N addition on the physiological properties of trees. However, it has been overlooked how elevated O and N addition affect tree immunity in face of pathogen infection, as well as of the important roles of phyllosphere microbiome community in host-pathogen-environment interplay. Here, we examined the effects of elevated O and soil N addition on poplar leaf rust [] severity of two susceptible hybrid poplars [clone '107': cv. '74/76'; clone '546': Í ] in Free-Air-Controlled-Environment plots, in addition, the link between -susceptibility and changes in microbial community was determined using Miseq amplicon sequencing. Rust severity of clone '107' significantly increased under elevated O or N addition only; however, the negative impact of elevated O could be significantly mitigated when accompanied by N addition, likewise, this trade-off was reflected in its phyllosphere microbial α-diversity responding to elevated O and N addition. However, rust severity of clone '546' did not differ significantly in the cases of elevated O and N addition. infection altered microbial community composition and increased its sensitivity to elevated O, as determined by the markedly different abundance of taxa. Elevated O and N addition reduced the complexity of microbial community, which may explain the increased severity of poplar rust. These findings suggest that poplars require a changing phyllosphere microbial associations to optimize plant immunity in response to environmental changes.
对流层臭氧和氮沉降是两种主要的环境污染物。大量研究聚焦于臭氧浓度升高的负面影响以及土壤施氮对树木生理特性的互补作用。然而，臭氧浓度升高和施氮如何影响树木面对病原体感染时的免疫力，以及叶际微生物群落宿主-病原体-环境相互作用中的重要作用却被忽视了。在此，我们在自由空气控制环境试验田中研究了臭氧浓度升高和土壤施氮对两种易感杂交杨树（无性系‘107’：cv.‘74/76’；无性系‘546’：Í）杨叶锈病[]严重程度的影响，此外，还使用Miseq扩增子测序确定了易感性与微生物群落变化之间的联系。仅在臭氧浓度升高或施氮情况下，无性系‘107’的锈病严重程度显著增加；然而，当施氮伴随臭氧浓度升高时，臭氧浓度升高的负面影响可显著减轻，同样，这种权衡也反映在其叶际微生物α多样性对臭氧浓度升高和施氮的响应上。然而，在臭氧浓度升高和施氮情况下，无性系‘546’的锈病严重程度没有显著差异。感染改变了微生物群落组成，并增加了其对臭氧浓度升高的敏感性，这由分类单元丰度的显著差异所决定。臭氧浓度升高和施氮降低了微生物群落的复杂性，这可能解释了杨树锈病严重程度增加的原因。这些发现表明，杨树需要不断变化的叶际微生物关联来优化植物免疫力以应对环境变化。
