Agriculture in Europe is grappling with increasing challenges posed by extreme weather conditions that result in substantial crop losses. In Germany alone, the agricultural sector suffered losses of approximately 770 million euros in 2018 due to these factors. Addressing these challenges, particularly in the context of climate change, is essential to secure global food production.
The VolCorn project has brought together scientists from four non-university research institutions to investigate how wheat plants, along with the microorganisms, such as fungi and bacteria, that inhabit them, respond to stressors induced by extreme weather conditions like drought, flooding, and pest infestations. The research aims to uncover the crucial role of microbiota, the community of microorganisms in and around the plant, in helping plants adapt to these stress situations.
One key aspect of the study focuses on volatile organic compounds (VOCs), which the plant both produces and uses to communicate with its microbiota. These VOCs play a critical role in the plant’s defense against stressors. Using advanced systems biology methods, the researchers have explored changes in plant metabolism and the microbiota simultaneously.
The findings reveal that floods and droughts not only lead to decreased wheat growth and yields but also trigger changes in the microbiota of both roots and leaves. Notably, during early growth stages, more pathogenic microbes tend to colonize stressed plants, rendering them more vulnerable to diseases.
Surprisingly, beneficial bacteria also thrive in the root zone during flooding, facilitating nutrient and vitamin uptake by the plant. Simultaneously, the plant undergoes significant metabolic alterations. The researchers have identified the central role of the amino acid alanine in maintaining nitrogen supply and metabolism in stressed plants. These changes in microbiota enable the provision of additional vitamins to support the weakened wheat metabolism in the root zone.
Pest infestations impact the formation of VOCs by wheat plants, leading to a defense response against this form of stress. The project has resulted in the development of a novel data analysis tool for complex mixtures of various VOCs using mass spectrometry, which promises to expedite further studies in this field.
Project coordinator Steffen Kolb from ZALF expresses hope that future efforts will enable the selective enrichment of microbes and their supportive properties, making wheat plants more resilient to climate change-related stressors like flooding. Initiatives in plant breeding are already underway, encouraging the colonization of plants with beneficial microorganisms from the surrounding soil and transferring stress-reducing microorganisms to wheat crops.
The knowledge gained from understanding the intricate relationship between wheat plants and their microbiota is of paramount importance for breeding climate-resistant wheat varieties and managing microorganisms systematically in agricultural crop production. Nonetheless, the research community acknowledges that further experimental research is necessary to explore these complex relationships fully.