In the new issue of Science, an international team of biologists, led by Franciska de Vries of the University of Amsterdam, urges the scientific community to spend more time researching the interaction of food crops with their root microbiome. They argue that this knowledge is essential for the protection of crops form the effects of droughts, and thus for making them more resilient to climate change.
Our changing climate poses a number of challenges for crop farmers. In some parts of the world, they will have to face increasing periods of drought. And solving this by increasing irrigation is not always an option. Fortunately, there may be other solutions.
Professor Franciska de Vries of the University of Amsterdam's Institute for Biodiversity and Ecosystem Dynamics is first author of the new paper. She explains: 'It is well-known that the bacteria and fungi living on plant roots influence the plant's health. It is comparable to the microbiome in our own guts. Beneficial bacteria living there are essential for our health, and the impact our microbiome has on our body depends on the types of bacteria present, their activity and their numbers.'
Making food crops resistant to stress
Scientific attention to the response of the soil microbiome to drought has increased over the past few years. However, most of this research has focused on the microbiomes of non-food crops. De Vries: 'We believe it is important to shift this focus. As our climate is changing, the need for food crops that are more resilient to different types of stress is increasing. If we have more knowledge about the way the root microbiome can help plants during stress, or recover from it, we can use this to protect crop yields.'
In their paper, the biologists highlight a number of promising directions of research. The relationship between plants and the micro-organisms associated with them is often complex. For instance, indirect effects of drought mediated by the plants can have a larger effect on the microbial community than the direct effects of the drought itself. One of the ways plants influence their microbiome is through so-called root exudate, the carbon-rich fluid excreted by plant roots on which micro-organisms feed. 'My own research has shown that grasses can change the composition of their root exudate under the influence of drought, thereby increasing the activity of their microbiome,' says De Vries. 'There are indications that this nudges the micro-organisms into releasing more essential nutrients from the soil, which in turn helps the grasses recover from the drought. I will be investigating this over the next few years in a new research programme I am starting in Amsterdam using a Starting Grant from the European Research Council (ERC). It will be very interesting to discover if something like this also applies to food crops.'
Multi-year project on root microbiomes
Unrelated to the research of De Vries and the current Science paper, a project supervised by UvA-biologist Harro Bouwmeester that focuses on root microbiomes recently received a research grant of 20 million euros from the Dutch Research Council (NWO). Studying the effects of environmental stress on microbiome-plant interactions in several types of plants, including food crops, is part of this large multi-year project.
Publication details:
Franciska T. de Vries, Rob I. Griffiths, Christopher G. Knight, Oceane Nicolitch, Alex Williams; Harnessing rhizosphere microbiomes for drought resilient crop production, in: Science, 17 April 2020.
