Overlooked: The role of bacterial viruses in plant health

June 16, 2020

We know how important bacteria and fungi are for the health of plants. In marine environments and in our own gut, bacteriophages (viruses that infect bacteria) are important in regulating the microbiome. Yet, their effect on bacteria living around the roots of plants has hardly been studied. 'I cannot believe that they are not important,' says Joana Falcao Salles, Professor of Microbial Community Ecology at the University of Groningen. She is the lead author of a review paper in Trends in Microbiology, which argues for more research into the role of bacteriophages in plant health.

Bacteria play an important role in many ecosystems. The possibility of large-scale DNA identification of microorganisms has revealed this over the past decade. But bacteria themselves are affected by bacteriophages, viruses that infect them. These phages can lyse the bacteria, which releases nutrients into the environment. On the other hand, the phages can live inside bacterial cells and affect their function. Finally, bacteriophages stimulate DNA transfer between cells and are known to have given cells new functionalities through this horizontal gene transfer.


'We know that soil bacteria are important for plants as well,' says Salles. Soils are deserts with very little food, as most nutrients are present in complex forms that microorganisms cannot readily use. However, in the few millimetres of soil around plant roots, plants stimulate the growth of bacteria. Plants release carbon sources for the bacteria and the bacteria provide nutrients and protection for the roots. 'This creates an oasis called the rhizosphere,' explains Salles.

Salles wrote the review article with former University of Groningen PhD student Akbar Adjie Pratama (now working as a postdoc at Ohio State University, US), MSc student Jurre Terpstra (who's bachelor thesis inspired the review) and visiting scientist Andre Luiz Martinez de Oliveria from Universidade Estadual de Londrina, Brazil. In it, she describes the role of bacterial viruses in modifying the microbial community in seawater and in the gut. 'If viruses are important in these systems, why would they not be important in the rhizosphere?' she asks. Nevertheless, this was the conclusion of a paper published not too long ago. 'The scientists had counted viral particles in the soil and found very few of them. However, bacteriophages can even have effects when they are living inside cells,' Salles explains.


Technical problems may also have affected studies into soil viruses, she adds: 'We have the technology to identify viruses in ocean water and in our gut. Finding them in soil is quite a challenge.' It is relatively simple to filter virus particles from water but isolating them from a slurry is far more complicated. Salles suspects that this has led to bacteriophages being overlooked. 'There are just a handful of institutes where soil phages are being studied.'

Her own institute, the Groningen Institute for Evolutionary Life Sciences, has only recently appointed a virologist. Salles and her team will now start to look for evidence of the importance of bacteriophages. 'For instance, certain phages could stimulate microbes that will protect plants during droughts.' In another project, Salles wants to test the effect of viruses on the potato microbiome, using a large number of different potato breeds.


'Microbes were once considered to be unimportant,' Salles continues, 'until microbiome technologies showed otherwise. Sequencing viruses has become much easier now and I cannot imagine that they are not important. Bacteriophages are the forgotten sibling and, in my opinion, we underestimate their importance.'

Simple Science Summary

Even bacteria can catch viruses. These viruses play an important role in nature. For example, they can change the number of certain bacterial species by killing bacteria, thereby freeing lots of nutrients or they can transfer DNA between cells. Bacterial viruses (also called bacteriophages) can play an important role in maintaining a healthy community of bacteria in our gut and can do the same in seawater. However, their role in soils is unclear. In a review article, Joana Falcao Salles, Professor of Microbial Community Ecology at the University of Groningen, argues that it is very likely that they are important for plant health: plants need bacteria around their roots to provide them with all kinds of nutrients and other compounds. Viruses will have an impact on these bacterial communities. Therefore, viruses are likely to be important for the health of plants.
Reference: Akbar Adjie Pratama, Jurre Terpstra, Andre Luiz Martinez de Oliveria, Joana Falcão Salles: The Role of Rhizosphere Bacteriophages in Plant Health. Trends in Microbiology, first online 13 May 2020

University of Groningen

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.