Strengthening legume crops
Along with climate change, food security - our ability to produce enough safe and nutritious food to feed Europe’s population - is a major concern, making improvements in the crop varieties we breed more important than ever. For the last 5 years an EU-funded consortium, ABSTRESS has been investigating how state of the art genetic technologies can be used to introduce sustainable commercial crop varieties, with direct resistance to adverse environmental or biological conditions. The 13-partner consortium, from 7 EU countries, studied legumes because, ‘uniquely amongst crops, they work with microorganisms to take nitrogen from the atmosphere into the plant roots and act as a natural fertiliser,’ says project coordinator Adrian Charlton from Fera Science in the UK. However, European legumes such as beans and peas can be quite susceptible to diseases, such as various plant pathogens that live in the soil and attack plants through their roots, causing the plants to wilt. ‘It results in unpredictable crop yields and is made worse by the sort of drought conditions that might become more common in Europe due to climate change’ adds Charlton. The ABSTRESS project applied comparative genomic approaches to study the networks of genes in pea plants that control the plants ability to grow in drought conditions or resist the effects of pathogens such as Fusarium. They also studied Medicago truncatula, a small low-growing clover-like legume native to the Mediterranean region. ‘It’s a fast growing plant that is commonly used as a model for legume crops as it has a small genome that is well understood and allows us to understand the molecular mechanisms involved in how the plant responds to drought and disease,’ explains Charlton. The genetic data generated was used to identify control “hub” genes in the crop and then to further identify similar genes in other crops such as tomato plants. From this information, new seeds were created with mutated versions of the important genes. As well as genetic analysis, plant material grown under stress was analysed with molecular imaging technologies such as x-ray and infra red imaging, to look inside the plants for early signs of stress. This, says Charlton, allowed the team to understand why some plants did better than others. ‘We were looking at pre-symptomatic drought and Fusarium stress so that we could work out which mechanisms the most successful plants use to protect themselves,’ he explains. In addition, the ABSTRESS team wanted to understand the role of soil microorganisms in plant health. ‘We showed that changing the genetics of the microorganisms that live in the root nodules of legumes can also potentially help to improve resistance to drought in particular,’ concludes Charlton. The consortium was ultimately able to produce pea mutants with promising genetic characteristics. ‘The novel collection of new seed varieties we have created will be put into commercial breeding programmes to assess its usefulness as a resource for breeding drought and Fusarium resistant plants.’ says Charlton, ‘this will be a benchmark for applying the latest technologies to breed a new generation of crops more able to cope with the challenges of climate change.’
Keywords
ABSTRESS, Fusarium, Medicago truncatula, pea mutants, pathogens, soil microorganisms, drought resistance
