Bacteria determine defense around rape seeds
The composition of the bacterial community around rape seeds strongly affects the vulnerability of the plant to pathogens. That is shown by research of dr. Daria Rybakova, of the BIOCOMES-partner Graz University of Technology, in Austria, and colleagues. Their research was published in the latest issue of the journal Microbiome.
One of the ways through which the BIOCOMES-partners seek to develop new biological products for plant protection, is through treating rape seeds with bacteria. Rybakova and colleagues analyzed the natural bacterial microbiome – the amount and the nature of the bacteria – around seeds of three different cultivars of the oil producing rape (Brassica napa). Rape is increasingly important as an oil-producing plant. In 2016, no less than 71 million tons of rapeseed were produced worldwide. Meanwhile, this crop is also increasingly being plagued by pathogens, such as the fungus Verticillium longisporum.
Much to their surprise, the authors report a high specificity of the bacterial communities linked to different cultivars of rape. The different cultivars shared only one third of their different bacterial strains. Apart form those ‘general bacteria’, each cultivar appeared to have it’s own unique bacterial community around the seeds.
Diversity causes strong to defense
Moreover, the amount of genetic diversity of the bacteria around a seed, appeared to be strongly linked to the possibilities to colonize the plant with new bacteria, either pathogenic or bacteria that are applied on purpose in biological seed treatment strategies.
New breeding strategies
The nature of the bacteria around a plant is mainly influenced by the exudates that are excreted by a plant’s roots. With the different cultivars strongly affecting the composition of the microbiome, the authors suggest there is a good potential to influence the plant’s bacterial defense to pathogens, by selective breeding. Moreover, the knowledge about the microbiome, and it’s influence on pathogens will also support the future development of new strategies to protect crops with biological control agents, being a major goal of the BIOCOMES-project.
- The structure of the Brassica napus seed microbiome is cultivar-dependent and affects the interactions of symbionts and pathogens; Rybakova D, Mancinelli R, Wikström M, Birch-Jensen AS, Postma J, Ehlers RU, Goertz S, Berg G. Microbiome, September 2017: DOI: 10.1186/s40168-017-0310-6 (Subscription or payment may be required).
- BIOCOMES research on Soil-borne Verticillium wilt