Working in the EU-funded EcoSeed project, the researchers are delving deep into the still poorly understood biochemical, biophysical and molecular processes that seeds undergo from their development on the mother plant through to germination. Their work will not only improve understanding of what causes some seeds to fail and others to grow into vigorous and healthy plants, but will contribute to the development of improved seed selection, storage and germination techniques in a changing environment.

“Seed quality is of critical importance to agriculture and the conservation of wild species,” explains Ilse Kranner of the University of Innsbruck’s Institute of Botany in Austria. “Climate change is having a direct impact on seed quality, putting some wild species at risk of extinction, causing considerable economic losses for the agricultural sector, undermining food security for consumers and compromising the livelihoods of farmers.”

One study puts the yield loss of major cereal crops from rising global temperatures at US$5 billion (€4.38 billion) a year between 1981 and 2002 – a figure that is only likely to increase as temperatures continue to rise and droughts and extreme weather conditions intensify.

Putting plants under stress

In order to determine precisely how environmental stresses, such as temperature and drought, impact seed quality, the EcoSeed team is studying four plant species: the commercial crops barley, sunflower and cabbage, as well as a cabbage relative, Arabidopsis – long used as a model organism for plant biology and the first plant to have its entire genome sequenced.

In a controlled environment, the researchers are subjecting the mother plants to environmental stresses and using advanced transcriptomics, proteomics and metabolomics analyses to study how these stress factors affect the genes, hormones, proteins, chemical composition and metabolism of the plant’s seeds. They are also looking at how different factors during seed storage, such as temperature, humidity and oxygen concentrations, affect seed viability, longevity and the vigour of seedlings.

“Seeds are extremely complex and undergo many changes before germinating and growing into the next plant generation. If environmental stresses are too great, some will never germinate, or the plants they grow into will be weak and unproductive,” Kranner notes.

For example, in temperate European climates many plants shed seeds in the autumn, but these dormant seeds will not germinate – even when the environmental conditions are ideal – until they undergo an extended period of low temperatures during the winter. The seed then “knows” that spring has arrived. This important trait is controlled by plant hormones and signalling compounds throughout the seed life cycle, all of which can be affected by environmental stress, such as an exceptionally warm winter.

By determining the cause and effect relationship between environmental factors and seed health, the EcoSeed researchers’ results will provide crucial new insights benefitting both seed conservationists and the agricultural sector.

Their work will contribute directly to the seed storage processes used by seed banks, including project partners IPK Gatersleben in Germany, the largest agricultural gene bank in the EU, and the Royal Botanic Gardens in the UK, which maintains the largest ex situ gene bank for wild plant species globally.

It will also contribute to better seed selection, treatment and germination processes for companies and organisations in the agricultural sector. This not only helps them to maintain crop yields in the face of climate change, but potentially even increases production, which benefits consumers and tackles food security issues.

“Within the agricultural sector, there is clear interest in the commercial applications of our work. The potential for the EcoSeed project results to be used commercially in the future is high, for example, for selecting and breeding more stress-tolerant crops,” Kranner explains. “From a scientific perspective, the work carried out in EcoSeed will undoubtedly continue after the project ends, particularly with a view to data-mining the vast amount of information about seed health we are generating.”