Rabbits prefer to eat plants with plenty of DNA, according to a new study by Queen Mary University of London and Royal Botanic Gardens, Kew.
The researchers also found that it is the opposite for invertebrates, like snails and insects, as they prefer to eat plants with much less DNA.
Many factors influence what herbivores such as rabbits eat but the role of genome size, which is the amount of DNA in an organism's cells, in herbivore-plant interaction was unknown.
In this study, published in Proceedings of the Royal Society B, the researchers suggest that genome size should be used as a new measure to improve ecological models which are designed to predict how plant communities will respond to ecological change, caused by climate or altered land use for example.
However, while the results suggest which plants rabbits and invertebrates prefer, they could also show that these plants are simply recovering more slowly after being eaten.
Professor Andrew Leitch, joint-lead author of the study from Queen Mary University of London, said: "We demonstrate that genome size plays a role in influencing plant-herbivore interactions, and suggest the inclusion of genome size in ecological models has the potential to expand our understanding of plant productivity and community ecology under nutrient and herbivore stress."
The study was carried out on grassland west of London, where herbivores have been excluded for eight years.
The researchers analysed plots that were then grazed by rabbits or grazed by invertebrates, like snails and insects, to determine which plants grew the most. They found that plants responded in different ways, depending on the herbivore.
It is thought that rabbits may favour plant species with large genomes because they are more nutritious, given that a plant genome is a rich package of proteins and nucleic acids needed by animals to build their own cells.
Invertebrates meanwhile are likely to have established themselves as specialists on plant species with small genomes because there are more available to them.
Plant genome sizes can vary hugely, with the largest at least 2,400 times bigger than the smallest. This has an impact on how and where plants can live and this study shows that species are differentially impacted by different types of herbivores depending on how much DNA is in each of their cells.
Dr Ilia Leitch, from Royal Botanic Gardens, Kew, added: "We argue that genome size needs to be considered in ecological models that are describing ecological processes. The functionality of these ecological models is essential if we are to establish good policy to mitigate against the negative effects of climate change, changing land use, eutrophication of our environment and to conserve our endangered species."
* Research paper: 'Interactions between plant genome size, nutrients and herbivory by rabbits, molluscs and insects on a temperate grassland. Maite S. Guignard, Michael J. Crawley, Dasha Kovalenko, Richard A. Nichols, Mark Trimmer, Andrew R. Leitch and Ilia J. Leitch. Proceedings of the Royal Society B.
* For a copy of the paper please contact below
Queen Mary University of London
Tel: 020 7882 3004
About Queen Mary University of London
Queen Mary University of London is a world-leading research-intensive university with over 25,000 students representing more than 160 nationalities.
A member of the prestigious Russell Group, we work across the humanities and social sciences, medicine and dentistry, and science and engineering, with inspirational teaching directly informed by our research.
In the most recent exercise that rated research in the UK, we were ranked 5th in the country for the proportion of research outputs that were world-leading or internationally excellent. We offer more than 240 degree programmes and our reputation for excellent teaching was rewarded with a silver in the 2017 Teaching Excellence Framework (TEF) awards.
Queen Mary's history dates back to 1785, with the foundation of the London Hospital Medical College. Our history also encompasses the establishment of the People's Palace in 1887, which brought accessible education, culture and recreation to the East End of London. We also have roots in Westfield College, one of the first colleges to provide higher education to women.
About The Royal Botanic Gardens, Kew
The Royal Botanic Gardens, Kew is a world famous scientific organisation, internationally respected for its outstanding collections as well as its scientific expertise in plant diversity, conservation and sustainable development in the UK and around the world. Kew Gardens is a major international and a top London visitor attraction. Kew's 132 hectares of landscaped gardens, and Wakehurst, Kew's Wild Botanic Garden, attract over 2.1 million visits every year. Kew was made a UNESCO World Heritage Site in July 2003 and celebrates its 260th anniversary in 2019. Wakehurst is home to Kew's Millennium Seed Bank, the largest wild plant seed bank in the world. Kew receives approximately one third of its funding from Government through the Department for the Environment, Food and Rural Affairs (Defra) and research councils. Further funding needed to support Kew's vital work comes from donors, membership and commercial activity including ticket sales.