The structure of the Brassica napus seed microbiome is cultivar-dependent and affects the interactions of symbionts and pathogens

Microbiome

Mariann Wikström¹  Ann-Sofie Birch-Jensen¹  Ralf-Udo Ehlers²  Riccardo Mancinelli³  Gabriele Berg³  Daria Rybakova³  Simon Goertz⁴  Joeke Postma⁵ 

[1] Agro Plantarum;E-nema GmbH;Graz University of Technology, Institute of Environmental Biotechnology;NPZ Innovation GmbH;Wageningen Plant Research;

关键词: Plant microbiome;    Seed microbiome;    Brassica Napus;    16S rDNA amplicon sequencing;    Confocal laser scanning microscopy;    Cultivar specificity;   

DOI  :  10.1186/s40168-017-0310-6

来源: DOAJ

【 摘 要 】

Abstract Background Although the plant microbiome is crucial for plant health, little is known about the significance of the seed microbiome. Here, we studied indigenous bacterial communities associated with the seeds in different cultivars of oilseed rape and their interactions with symbiotic and pathogenic microorganisms. Results We found a high bacterial diversity expressed by tight bacterial co-occurrence networks within the rape seed microbiome, as identified by llumina MiSeq amplicon sequencing. In total, 8362 operational taxonomic units (OTUs) of 40 bacterial phyla with a predominance of Proteobacteria (56%) were found. The three cultivars that were analyzed shared only one third of the OTUs. The shared core of OTUs consisted mainly of Alphaproteobacteria (33%). Each cultivar was characterized by having its own unique bacterial structure, diversity, and proportion of unique microorganisms (25%). The cultivar with the lowest bacterial abundance, diversity, and the highest predicted bacterial metabolic activity rate contained the highest abundance of potential pathogens within the seed. This data corresponded with the observation that seedlings belonging to this cultivar responded more strongly to the seed treatments with bacterial inoculants than other cultivars. Cultivars containing higher indigenous diversity were characterized as having a higher colonization resistance against beneficial and pathogenic microorganisms. Our results were confirmed by microscopic images of the seed microbiota. Conclusions The structure of the seed microbiome is an important factor in the development of colonization resistance against pathogens. It also has a strong influence on the response of seedlings to biological seed treatments. These novel insights into seed microbiome structure will enable the development of next generation strategies combining both biocontrol and breeding approaches to address world agricultural challenges.

【 授权许可】

Unknown