Ensuring that plants can access essential nutrients is one of the major challenges of modern agriculture, particularly in coastal regions with a Mediterranean climate, with calcareous soils that have low iron availability. Although this element is often present, it is not always available in a form that can be easily absorbed by plants. This causes the development of iron chlorosis — a physiological problem that reduces the growth, productivity and quality of crops.
It was within this context that Teresa Saavedra developed her doctoral work, investigating how plants regulate their physiology in response to iron deficiency, with a particular focus on interspecies interactions and the role of compounds released by roots as a strategy to improve iron nutrition. The research benefited from the interdisciplinary scientific environment of CCMAR and access to infrastructure, analytical technologies, and cross-cutting knowledge that have supported projects such as AgroSERV and AQUASERV, aligned with European policies on food security, sustainability, agricultural resilience, and ecosystem recovery (examples: Farm to Fork Strategy and Sustainable Development Goals).
“My work focused on understanding how interactions between plants can improve iron nutrition and reduce chlorosis through physiological responses that go beyond classic absorption mechanisms.” – Teresa Saavedra
Throughout her PhD, Teresa studied three widely used perennial grasses — Poa pratensis, Lolium perenne and Festuca rubra.
Perennial grasses are plants that live for several years and maintain a permanent root system, allowing them to regrow after cutting, grazing or periods of environmental stress. They are widely used in pastures, animal feed, lawns and green spaces, as well as in sustainable agricultural systems, due to their high resistance, adaptability and contribution to soil protection and fertility. These characteristics make them particularly relevant in regions with a Mediterranean climate, where the limitation of nutrients such as iron represents a growing challenge for agricultural productivity.
To understand how these plants cope with iron deficiency, the grasses were grown under different levels of iron availability. The results showed that when iron is scarce, plants do not remain passive: they adjust their root growth and release a set of chemical compounds into the soil that help make iron more accessible. These compounds include organic acids, phenolic compounds and small peptides, which are able to bind to iron and facilitate its absorption, while protecting the plant from the effects of stress caused by nutritional deficiency.
Unexpectedly, the study also revealed that these grasses activate mechanisms normally associated with other plant groups, showing that iron acquisition strategies are more flexible than previously thought. Among the species analysed, Festuca rubra stood out for its high adaptability, maintaining growth even in conditions of low iron availability, which reinforces its potential for use in more resilient agricultural systems.
Results with practical impact
The results of this work have direct implications for sustainable agriculture:
- They contribute to the development of strategies based on plant physiology, reducing dependence on chemical soil amendments.
- They support the use of intercropping systems to improve nutrient availability naturally.
- They provide essential knowledge for the management of problematic soils, common in Mediterranean and calcareous regions.
- They help to understand how plants cope with nutritional stress in the context of climate change.
- Although the study was conducted under controlled conditions, the results establish a solid basis for future applications in real agricultural soils, where the interaction between plants, soil and microbiota plays a decisive role.
Looking to the future
With her PhD completed and her results published, Teresa intends to continue her scientific career in the field of plant sciences, contributing to the advancement of fundamental knowledge and the development of more sustainable and efficient agricultural solutions, especially those adapted to adverse environmental conditions.
“CCMAR provided a stimulating scientific environment, with access to infrastructure, technical support and a context of knowledge sharing that was essential to the success of this research. My goal is to continue working in science that helps solve real problems, linking physiological knowledge of plants to more sustainable agricultural practices.” – Teresa
References:
Saavedra, T., Pestana, M., da Silva, J.P., Correia, P.J. (2025). Metabolites released by Poaceae roots under iron deficient conditions. Journal of Plant Nutrition and Soil Science, 188, 312-323.
doi.org/ 10.1002/jpln.202400307
