Plants. They soak up carbon dioxide and breathe out oxygen. They are food, clothing, medicine, power and building materials. We have harnessed so many benefits from the botanical world and yet we are only really scratching the surface of a realm which still holds many secrets and discoveries.
Food production is one area where humans will most likely always depend on plants. Every school child knows that plants, through the process of photosynthesis, use the sun to make sugar and this forms the basis of most food chains – including our own. As those with vegetables patches or allotments know though, in producing food crops, we are embroiled in an age-old arms race with pests and diseases.
Warwick’s Crop Centre – based at the university’s Wellesbourne campus – is a specialist research unit looking at the production of many of the plant species which are economically important crops in the UK. Researchers are carrying out work on carrots, onions, lettuce and brassicas, among others, to improve the plants themselves or understand their associated pest and diseases. The work carried out at Wellesbourne has a direct impact on improving the food we buy and eat.
Stopping the rot
Dr John Clarkson is a Reader at the Crop Centre working on plant diseases with a particular focus on a mysterious but hugely damaging pathogen – Fusarium oxysporum.
He explains: “Fusarium oxysporum is a soilborne fungus which has many different forms adapted to infect different host plants which causes some of the most devastating diseases in horticulture. The different types of the fungus can be detrimental to a wide variety of crops including lettuce, tomato, brassicas, asparagus, cucumbers, peppers, coriander, spinach, basil, beans, peas, strawberry and watermelon, causing root and stem rots which result in wilted plants and subsequent death.
“However, there are also some non-pathogenic isolates which are also beneficial members of the soil’s ecosystem. As this fungus is so varied – both in what it looks like and its genetic makeup – it is very difficult to distinguish between the types which attack different plants and also between the damaging and beneficial forms, without longwinded and expensive testing on plants. To address this we are developing specific DNA-based tests to more quickly identify the forms that damage particular crops.
Knowing your onions
“One particular target we are looking at Wellesbourne is Fusarium oxysporum f.sp. cepae (FOC) which causes basal rot in onion bulbs and causes losses estimated at a minimum £11 million a year in the UK alone. In some cases, entire crops can be lost either in field or in store. FOC produces long-lived spores which makes control difficult. In the past we relied on techniques like soil sterilisation or pasteurisation and fungicidal drenches or seed treatments. However, these approaches may not be effective, and can have negative impacts on the environment. We also know that legislation surrounding chemical treatment of crops and seeds is changing and some products may not be permitted in future.
“We are therefore working towards both identifying FOC and also understanding plant resistance to basal rot in onion, studying the genetic makeup of those plant lines which seem to stand up to the pathogen and identifying associated genetic markers in this process. The highly desirable outcome would be to produce varieties of onion with resistance to FOC, therefore reducing the need for expensive fungicide treatments.”
Fuelling the future
Another hugely important area where humans can harness the power of plants is energy production. Using plants as fuel goes hand in hand with the development of the human race – fire is, after all, the secret to our success. Fossil fuels are plant-based of course – with coal, gas and oil the product of plant breakdown over hundreds of millions of years – but they are dirty and detrimental to the environment. Biofuels were hailed as the green solution – but is this still the case?
The search is on for the next generation of plant fuels, as Rob Lillywhite, assistant professor in Life Sciences at Warwick and an expert on environmental accounting and the tradeoffs within production systems, explains:
“Biofuels are nothing new anymore. The Brazilians popularised the idea of growing plants to produce fuel 40 years ago; in their case turning sugarcane into ethanol to power their cars. Europe was a little late to the party but belatedly recognised that plants might offer a more sustainable way of producing fuel. Sugarcane was out though because the region is too cold, so other plants and other types of energy were considered.
“The most popular, and still increasing, approach was to use anaerobic digestion (AD) to turn forage maize into biogas (a mixture of methane and carbon dioxide). This can be cleaned and fed into the national gas grid or combusted at the production site to produce electricity.
“Forage maize is a good crop for this approach since its yield per hectare is high and farmers already understood how to grow it since it is used to make silage for feeding to cattle. Anaerobic digesters are often referred to as concrete cows since they and cattle share the same decomposition process. However, as the area of forage maize for AD has grown so have concerns over its environmental cost and production has been implicated in damaging soil quality and giving rise to flooding. One issue is that forage maize is an annual crop that requires growing from seed every year and it is also harvested in autumn under sometimes less than ideal conditions.”
Are there alternatives?
“There are a number, including native and non-native grass species,” explains Rob Lillywhite. “But our focus is on an American import – the Cup Plant. This perennial can occasionally be found as a garden plant but its true vocation in Europe might be as an industrial crop. It has similar yield potential to forage maize but the added benefit of requiring little in the way of fertiliser and maintenance, and its bright yellow flowers are attractive to pollinator insects.
“Recent research has shown that it has the potential to become a useful feedstock material for AD and make a useful contribution to the countryside as well as our energy supply.”
John Clarkson and Rob Lillywhite will be talking about their work at a public event held at School of Life Sciences at the Wellesbourne Campus, in celebration of Fascination of Plants Day. There will be talks and demonstrations to showcase several fascinating aspects of Warwick’s research on plants - focusing on food production and protecting the natural environment. The aim of Fascination of Plants Day is to get as many people as possible around the world fascinated by plants and enthused about the importance of plant science.
The event takes place on Thursday May 18, 6-8pm. More information is available here.
Dr John Clarkson is a plant pathologist and research leader in the Warwick Crop Centre specialising mainly in pathogens of vegetable crops. His areas of interest and expertise include plant pathogen biology, epidemiology, ecology and diversity with particular focus on soilborne diseases such as Sclerotinia and Fusarium and disease management approaches such as biological control and disease forecasting.
Rob Lillywhite is research biologist with particular interest is systems sustainability and a research programme focusessed on two sectors: agriculture/food and healthcare. His work uses environmental accounting techniques (life cycle assessment, footprinting, mass balances) to examine the trade-offs and impacts that occur within systems.