Scientists in Sheffield working on the fundamental biological processes of plants could make significant difference to the lives of farmers in many parts of the world. Using model plant species, such as the tiny weed Arabidopsis, the researchers have uncovered one of the processes used by the plants to protect themselves from potentially lethal environmental conditions. Their discoveries are now being applied to improve the productivity of bean farmers in South America and rice producers in Asia.

Very high levels of sunlight can be hazardous to plants, overwhelming their ability to photosynthesise. This effect is exaggerated when there is a shortage of water or extreme temperatures. The resulting damage to the delicate photosynthetic membranes in the plant leads to impaired growth, cell destruction and, eventually, plant death. The scientists, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), have found that plants are able to turn unwanted absorbed light into heat by altering the structure of one of the proteins in these membranes. This unique nanoscale safety valve prevents plant damage by harmlessly dissipating the lethal excess radiation. This photoprotective process was found to be aided by a special carotenoid molecule called zeaxanthin and plants with higher levels of this molecule appear to be better protected.

Professor Peter Horton, research leader at the University of Sheffield, said, “Plants use a range of processes to adapt to harsh and potentially damaging environmental conditions. We are beginning to understand the mechanisms plants have at a molecular level to prevent damage from excess sunlight. We hope that this knowledge could be used to improve photosynthesis rates, and therefore productivity, in staple crops that feed millions in parts of the world where environmental conditions can be particularly harsh.”

Professor Horton continued, “To fully apply this research to improving the productivity of crops we need to understand how these processes relate to plant growth and development in field conditions. Processes that may appear important in the laboratory may not be in the varied conditions of the field.”

The researchers have been working with agricultural institutes in South America and the Asia to start to work out how their knowledge of the defence mechanisms in model plants such as Arabidopsis could be used to improve the photosynthesis rates of staple crops such as rice and the common bean.

This research appears in the January 2006 issue of BBSRC Business, the quarterly research magazine of the Biotechnology and Biological Sciences Research Council.

The Horton lab is at the University of Sheffield, in the Department of Molecular Biology and Biotechnology. The aim of the lab is to provide training and research in photosynthesis in higher plants. The research is multidisciplinary – the aim is to understand not only the molecular mechanisms involved but also how these are integrated into the growth and development of the whole plant. The group aims to understand basic biological processes and to learn how this knowledge may be applied to agriculture and nanotechnology. The lab comprises both experienced and young postdoctoral researchers, undergraduate and postgraduate students and research technicians. It has collaborations with labs in 12 countries across 5 continents, and has published over 150 papers since it was formed 25 years ago. www.photosynthesis.uk.net

Peter Horton is Professor of Biochemistry and leads a research group on plant light harvesting which is funded by BBSRC and part of an EU Marie Curie Research Training Network. He co-ordinated an EU-funded project to study genotypes of the common bean Phaseolus vulgaris. The project included researchers from the International Center for Tropical Agriculture (CIAT) in Colombia and Universities in Chile, Bolivia, Germany and Italy.

The research on rice is in collaboration with the International Rice Research Institute (IRRI) in the Philippines and has been jointly funded by BBSRC and the Department for International Development. By 2025 there will be an estimated 4 billion consumers of rice in the world. To meet this demand rice yields must be increased by 38 per cent from current levels.

The Biotechnology and Biological Sciences Research Council (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £336 million in a wide range of research that makes a significant contribution to the quality of life for UK citizens and supports a number of important industrial stakeholders including the agriculture, food, chemical, healthcare and pharmaceutical sectors.