Managing plant stress in the era of climate change: Realising global sustainable development goals
Posted 17th February 2020 by Liv Sewell
Dr Salme Timusk was the first to show that native soil bacteria have the ability to protect plants against drought conditions. Salme writes here about plant microbiome interaction studies: how they can facilitate plant health and contribute to solutions for climate change.
Climate change has resulted in significant changes in weather patterns, precipitation distribution, and temperature/moisture fluctuations. This automatically influences plant pathogens and more severe problems in forestry and agriculture are the results.
On the UN initative, the year 2020 is the international year of plant health. The document notes that healthy plants constitute the foundation for all life on Earth, as well as ecosystem functions and food security, and are key to sustaining life on Earth. It is recognized that plant health is key to the sustainable development of agriculture to feed the growing global population by 2050. It also notes that sustaining plant health protects the environment, forests, and biodiversity from plant pests; addresses the effects of climate change; and supports efforts to end hunger, malnutrition, poverty; boosts economic development; and that the protection of plant health from pests is a key factor in strategies to eliminate hunger and rural poverty.
Considering Complexity is Crucial
For feeding the increasing world population the total crop production will need to increase significantly, under the challenge of less arable land and more severe environmental conditions. To be able to fulfill the goal we need new insights into plant protection and growth promotion, focusing on cross border disciplines and involving specialists capable of interpreting the complexity of systems. In natural settings, plants are exposed to an enormous variety of complex ever-changing signals.
In recent years, research has mainly concentrated on understanding plant responses to individual abiotic or biotic factors, although it is clear that the response to simultaneous factors is bound to lead to a much more complex scenario. Depending on the challenges, from the perception of the stimulus to the final response in cells, plants use various signaling pathways. Plants respond in a specific manner when they must face more than one stress simultaneously and the response cannot be predicted based on the plant’s response to the individual single stimulator. Dependent on the specific combination of stimulators and even on the degree of it, various interactions can take place after perception of the stimulus. The simultaneous factors can be antagonistic, synergistic or additive and complex stimuli may help or hinder plant adaptation to stress factors.
The concept of the station for measuring ecosystems atmospheric relations (SMEAR Estonia) is to measure complex concentrations and fluxes of energy and matter in the system. The system consists of different compartments (atmosphere, forests, lakes, peatlands, arable land). The concentration of matter or energy tell us about the “content” of the compartments. Fluxes of matter or energy tell us about the “change” of the “content” within the whole system. The dynamic of the system is mediated by a multitude of biological, chemical and physical processes. The processes act on multiple scales.
SMEAR Estonia is part of the Estonian Roadmap Project (Estonian Environmental Observatory). The project covers research stations all over Estonia and the aim is to do research and monitoring on atmosphere-biosphere interactions, marine and limnological sciences, and land ecosystems.
Microbial biodiversity and climate change
It is well documented that climate change is accompanied by various species extinctions and this is a challenge to ecosystem function. In this pattern, microorganisms are generally not discussed due to their invisibility and limited knowledge on ecosystems’ microbial diversity. At the same time, it is clear that microorganisms are fundamental to maintaining healthy environments. While the human effect on microorganisms is less obvious, the major concern focuses on changes in microbial populations and activity, which may affect the resilience of plants and influence their ability to respond to climate change. Microorganisms make a major contribution to carbon sequestration. Yet microorganisms may also contribute substantially to greenhouse gas emissions. Many factors influence the balance of microbial greenhouse gas capture versus emission.
It is generally accepted that microorganisms can influence plant fitness and the directed integration of microbial communities represents a promising sustainable solution to improve agricultural and forestry resilience. Understanding plant microbial endophytic and multi-cellular communities, such as biofilms, is highly significant from agricultural and ecological perspectives, as they play a critical role in plant adaptation to stress situations. While it is well known that plant response following exposure to microorganisms strongly depends on its developmental stage, it is less known that the response also depends on environmental conditions.
Microbes use a variety of mechanisms to coordinate activity within a community to accomplish complex multi-cellular processes. The plant combination with microorganisms leads to an increased accumulation of a large number of signaling compounds that are dependent on environmental stimuli. “Omics” technology combined with high-resolution microscopy, along with other novel approaches, can help us understand plant behavior under combinatorial stimuli. Transcriptomics, proteomics, and metabolomics have revealed plant responses under stress and their underlying mechanisms and point to potential target genes, proteins or metabolites for inducing tolerance and improved plant responses. Picking the best existing genomic molecular and microscopic technologies, we can reconstruct plant biochemical reaction networks and combine this with SMEAR station ecosystem data networks.
In this way, we are able to create systems for understanding microbial isolate actual effects on plants. The complex picture contributes to revealing the critical factors of microbial isolates promoting/protecting effect, but also the factors of plasticity between the plant beneficial effects and carbon balance of the biome. This helps in detecting plant stress and/or its alleviation in the early stages. Eventually, it leads to finding optimal fairways, inoculum composition, time, mode and quantity, i.e. a navigable channel for maximizing the microbial isolate and expected positive effect for minimizing the time it takes.
In summation
An essential goal of science is to look as far ahead as possible. Therefore, knowing the past and understanding the nature of current problems brings us to the point of developing actual solutions. Plant microbiome interaction studies, examined at a finer scale, linked to the observations at the SMEAR station, performed in accordance with developing the monitoring factors for carbon balance, will lead to a better understanding of the complex interactions of micro- and macrosystems. This will bring us to an improved perception of the system and result in biome design models for agro-ecosystems along with the identification of the best practices for microbial application in the systems.
Salme Timmusk is Associate Professor, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Science for Life Laboratory, Sweden. Her work focuses on molecular and ecological mechanisms of plant microbe interactions.
Salme Timmusk*, Julian Conrad2, Ylo Niinemets3, Eviatar Nevo4, 5, 6 , Lawrence Behers1, Jonas Bergquist7, and Steffen Noe3 presented a poster at The 4th Partnerships in Biocontrol, Biostimulants & Microbiome Congress: USA. You can view the full poster here.
Explore the latest developments in plant genomics, including omic technologies and adaptation to environmental and biological stress, at the 8th Plant Genomics and Gene Editing Congress: Europe. View the programme.
References
1 Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Science for Life Laboratory, Sweden
2 Swedish National Cryo-EM Facility, Science for Life Laboratory, Sweden
3 Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
4 International Graduate Centre of Evolution, University of Haifa, Israel
5 National Academy of Sciences, USA
6 Tauber Bioinformatics Research Centre, Israel
7 Department of Analytical Chemistry, Uppsala University, Sweden
* P.O. Box 7026, SE-75007 Uppsala, Sweden [email protected]
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