Contrasting Responses of Rhizosphere Bacterial, Fungal, Protist, and Nematode Communities to Nitrogen Fertilization and Crop Genotype in Field Grown Oilseed Rape (Brassica napus)
Contrasting Responses of Rhizosphere Bacterial, Fungal, Protist, and Nematode Communities to Nitrogen Fertilization and Crop Genotype in Field Grown Oilseed Rape (Brassica napus)
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DOI：
10.3389/fsufs.2021.613269
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
E. Picot;C. Hale;Sally Hilton;G. Teakle;H. Schäfer;Yong-Ju Huang;S. Perryman;J. West;G. Bending
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文献类型：
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作者：
E. Picot;C. Hale;Sally Hilton;G. Teakle;H. Schäfer;Yong-Ju Huang;S. Perryman;J. West;G. Bending
根际微生物组被认为在决定作物健康方面起着关键作用。然而，目前对塑造微生物组组装和组成的因素的理解严重偏向于细菌群落，与其他微生物组的相关性尚不清楚。此外，社区组装是由多种因素，包括主机基因型，环境和农业管理措施，其相对重要性和相互作用仍有待阐明。通过田间试验，研究了氮肥对10个不同基因型油菜根际细菌、真菌、线虫和原生生物群落的影响。我们发现，根际和非根际土壤之间的细菌，真菌，原生生物和线虫群落组成的显着差异。施氮对真菌、细菌和原生生物群落组成有显著但较弱的影响，这与根际和土壤中真菌病原体复合体的相对丰度增加有关，包括球腔菌属和小球腔菌属。网络分析表明，施氮对土壤和根际微生物群落的连通性有不同的影响。作物基因型显著影响真菌群落组成，有证据表明，包括L。斑点病菌，链格孢属，Pyrenopeziza brassicae、Olpidium brassicae和L. biglobosa，也可能有益的Heliotales根内生菌。作物基因型对细菌、原生生物和线虫群落的聚集没有显著影响。作物基因型间的遗传距离与根际微生物群落的差异程度无关。田间病害评估证实作物感染了小球腔菌属，和链格孢属（Alternaria sp.），表明根际微生物组测序是植物健康的有效指标。我们的结论是，在田间条件下，土壤和根际养分化学计量和作物基因型是决定作物健康的关键因素，通过影响病原和互惠真菌群落的根感染，根际微生物相互作用网络的连通性和稳定性。
The rhizosphere microbiome is considered to play a key role in determining crop health. However, current understanding of the factors which shape assembly and composition of the microbiome is heavily biased toward bacterial communities, and the relevance for other microbial groups is unclear. Furthermore, community assembly is determined by a variety of factors, including host genotype, environment and agricultural management practices, and their relative importance and interactions remain to be elucidated. We investigated the impact of nitrogen fertilization on rhizosphere bacterial, fungal, nematode and protist communities of 10 contrasting oilseed rape genotypes in a field experiment. We found significant differences in the composition of bacteria, fungi, protist and nematode communities between the rhizosphere and bulk soil. Nitrogen application had a significant but weak effect on fungal, bacterial, and protist community composition, and this was associated with increased relative abundance of a complex of fungal pathogens in the rhizosphere and soil, including Mycosphaerella sp. and Leptosphaeria sp. Network analysis showed that nitrogen application had different effects on microbial community connectivity in the soil and rhizosphere. Crop genotype significantly affected fungal community composition, with evidence for a degree of genotype specificity for a number of pathogens, including L. maculans, Alternaria sp., Pyrenopeziza brassicae, Olpidium brassicae, and L. biglobosa, and also potentially beneficial Heliotales root endophytes. Crop genotype had no significant effect on assembly of bacteria, protist or nematode communities. There was no relationship between genetic distance of crop genotypes and the extent of dissimilarity of rhizosphere microbial communities. Field disease assessment confirmed infection of crops by Leptosphaeria sp., P. brassicae, and Alternaria sp., indicating that rhizosphere microbiome sequencing was an effective indicator of plant health. We conclude that under field conditions soil and rhizosphere nutrient stoichiometry and crop genotype are key factors determining crop health by influencing the infection of roots by pathogenic and mutualistic fungal communities, and the connectivity and stability of rhizosphere microbiome interaction networks.