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Plants design their own environments

Plant roots can influence their local microbiological environment to a significant extent. Researchers aim to use this ability in plants to increase yield and reduce the use of pesticides in agriculture.

2016.08.10 | Janne Hansen

Plant roots can affect the plant's local environment. This ability can perhaps be used to reduce pesticide use. Photo: Colourbox

We are more than just ourselves – our microbes are an important part of us. Recent years have witnessed an increasing interest in the effect of our intestinal flora on health. Humans and animals are not the only ones with close relations to their microbiota; plants also have the same relations with their microbiome. Researchers from Aarhus University will now have a closer look at this interaction.

If we achieve a better understanding of how plant roots affect their immediate microbiological environment as a protection against plant diseases we may be able to utilise the plants’ abilities in this area to increase crop yield and reduce agricultural pesticide use.  

Researchers from Aarhus University aim to create new knowledge in this field in collaboration with researchers from Virginia Polytechnic Institute and State University and University of California Davis in a new three-year project that has received 6.3 million kroner in funding from the Danish Council for Independent Research – Technology and Production. 

Life beneath the soil

Strange things happen beneath the soil; fighting as well as cooperation between plant roots, the immediate environment and the surrounding microbes (microbiome).

The microbiome in and surrounding the plant roots has huge biodiversity. Some of the microbes – the pathogens – can promote diseases in plants. The more friendly microbes protect plants against pathogens, help provide them nutrients, produce plant growth hormones and increase resistance to other types of stress such as cold or draught.  

To a certain extent, plants can fend off pathogens by influencing the composition of their individual microbiomes. If we could control this impact we might eventually help plants design improved microbiomes to protect them against diseases.

- Plant roots release substances that affect the root microbiomes. It is our hypothesis that plant roots actively design their microbiomes to their own benefit in order to resist diseases in the roots, mainly by releasing specific substances to the root environment, explains the project leader, Section Manager Mogens Nicolaisen, Department of Agroecology, Aarhus University.

Exploring the microbiome

Plant improvement and cultivation systems may be even more systematic once we achieve further knowledge on the mechanisms controlling the plant’s ability to design its own microbiome. This might mean that the farmer will be able to increase his yield and minimize pesticide use.

- Actually, we have already tried to affect the plant microbiome for generations without knowing it by means of crop rotation, adding organic material to the soil and plant improvement, says Mogens Nicolaisen.

New technologies allow scientists to achieve an extensive and detailed knowledge on the specific nematodes, bacteria, fungi and oomycetes that constitute the microbiome and also how to affect the composition of the microbiome.

The scientists aim to illustrate the interaction between a specific root pathogen (Pythium irregulare), the microbiome in and surrounding the roots as well as the exudates released by the roots of a model plant (Arabidopsis).

For this purpose the scientists will make use of advanced metabarcoding and metabolomics technologies. Metabarcoding is a rapid method of biodiversity assessment. The method combines DNA based identification and high-throughput DNA sequencing. Metabolomics is the systematic study of the unique chemical fingerprints that specific cellular processes leave behind.

The scientists will generate huge datasets and identify the exudates and microorganisms that are important in relation to disease resistance and further examine the impact of these.

- The new technologies make it possible for us to measure the impact of changes – on the plant microbiome – of cultivation systems or plant improvement. The knowledge achieved will be an important step towards targeted microbiome designs with health promoting effect on roots. If you optimize the plant root microbiome you will achieve improved plants in the future that require less pesticides, says Mogens Nicolaisen.


For further information please contact

Section Manager Mogens Nicolaisen
Department of Agroecology
E-mail: mn@agro.au.dk
Telephone: +45 8715 8137  

Sustainable Pest Management is one of the research areas in which the Department of Agroecology is particularly strong and from which results are delivered in line with national and global societal challenges and goals.

  

Agro, DCA, Crops