In collaboration with researchers at Nanjing Agricultural University, Dr Tony Miller from the John Innes Centre has developed rice crops with an improved ability to manage their own pH levels, enabling them to take up significantly more nitrogen, iron and phosphorous from soil and increase yield by up to 54 percent.
Rice is a major crop, feeding almost 50 percent of the world’s population and has retained the ability to survive in changing environmental conditions. The crop is able to thrive in flooded paddy fields – where the soggy, anaerobic conditions favour the availability of ammonium – as well as in much drier, drained soil, where increased oxygen means more nitrate is available. Nitrogen fertilizer is a major cost in growing many cereal crops and its overuse has a negative environmental impact.
The nitrogen that all plants need to grow is typically available in the form of nitrate or ammonium ions in the soil, which are taken up by the plant roots. For the plant, getting the right balance of nitrate and ammonium is very important: too much ammonium and plant cells become alkaline; too much nitrate and they become acidic. Either way, upsetting the pH balance means the plant’s enzymes do not work as well, affecting plant health and crop yield.
Scientists at the John Innes Centre (JIC) and The Sainsbury Laboratory (TSL) have pioneered a new gene-detecting technology which, if deployed correctly could lead to the creation of a new elite variety of wheat with durable resistance to disease.
Working with fellow scientists at TSL, Dr Brande Wulff from the JIC developed the new technology called ‘MutRenSeq’ which accurately pinpoints the location of disease resistance genes in large plant genomes and which has reduced the time it takes to clone these genes in wheat from 5 to 10 years down to just two.
Effective use of these resistance genes in wheat could increase global yields and vastly reduce the need for agro-chemical applications.
A resistance gene acts like a simple lock keeping the pathogen from infecting the plant. Over time, as many breeders and growers have found, pathogens can adapt to overcome an individual resistance gene and infect the plant. A stack of multiple genes acts like a multi-lever lock, making it much harder for new pathogens to evade the crop’s defences.
Dr Brande Wulff said:
“The challenge has always been finding enough resistance genes to create an effective multi-gene ‘stack’ against virulent pathogens like wheat stem rust and wheat yellow rust which, if left unchallenged, can decimate crops across the world. With the advent of this new technology, the development of a new variety of wheat with strong resistance to one or more of these pathogens is now within reach.”
Using this technology, scientists can very quickly locate resistance genes from crops, clone them and stack multiple resistance genes into one elite variety.
MutRenSeq is a three step method for quickly isolating resistance genes based on (i) creating mutants from resistant wild type wheat plants and identifying those with loss of disease resistance, (ii) sequencing genomes of both wild type resistant plants and those which have lost resistance, and finally (iii) comparing these genes in mutants and wild types to identify the exact mutations responsible for the loss of disease resistance.
Dr Wulff collaborated with Drs Evans Lagudah and Sam Periyannan at CSIRO Agriculture in Australia, who had used a chemical (EMS) to cause mutations in the genomes of a sample of resistant wild type wheat plants. They then screened the mutant population by infecting it with the pathogen, to identify mutants that were no longer resistant.
The hypothesis was that these mutants would all share mutations in a common gene, which must be the resistance gene. They compared the sequences of the mutants to one another and looked for the overlap. Sequencing one mutant will identify several hundred mutations – each mutation indicating a candidate gene.
However, by comparing two mutants to each other, and looking for the overlap, the list is reduced from a few hundred, to just a handful.
Comparing three or more mutants, enabled the team to identify an overlap of only a single gene in the susceptible wheat plants.
Dr Wulff said:
“With MutRenSeq we can find the needle in the haystack: we can reduce the complexity of finding resistance genes by zeroing in from 124,000 genes, to just a single candidate gene.”
In the first test run of MutRenSeq, Dr Wulff’s team successfully isolated a well-known resistance gene, Sr33, in a fraction of the time it had previously taken to do this by conventional breeding techniques. Following this success, the team then cloned two important stem rust resistance genes, Sr22 and Sr45, which scientists have until now, been unable to isolate successfully.
According to the UN Food & Agriculture Organisation (FAO) wheat is grown on more land area than any other commercial crop (approximately 240m hectares) and continues to be the most important food grain source for humans.
Farmers in the west rely on pesticides to control pathogens in wheat but fewer and fewer agrochemicals are available for use due to concerns over their environmental impact. Farmers in poorer countries have little or no access to these chemicals and are highly vulnerable to disease-related losses, which can lead to hunger and malnutrition.
The UN Food and Agriculture Organization (FAO) estimates that 31 countries in East and North Africa, the Near East, Central and South Asia, which account for more than 37 percent of global wheat production area and 30% of global production, are at risk of wheat rust diseases including the Ug99 race of stem rust and Yr27 strain of yellow rust.
An alternative to pesticide-use is to build resistance into the crop by introducing resistant genes from other varieties of wheat into elite varieties.
Dr Wulff said:
“Finding and cloning these crucial genes has up until now been like looking for a needle in a haystack. The wheat genome is huge and contains many repeats. This new technology will transform this part of the scientific process.
“Though the next stage of stacking large numbers of genes correctly in the complex wheat genome is not easy and may take time, the advent of this new gene-detecting technology has brought the creation of one or more new elite varieties of wheat with long-awaited durable disease resistance much closer.”
New research led by Professor Cathie Martin of the John Innes Centre has revealed how a plant used in traditional Chinese medicine produces compounds which may help to treat cancer and liver diseases.
The Chinese skullcap, Scutellaria baicalensis – otherwise known in Chinese medicine as Huang-Qin – is traditionally used as a treatment for fever, liver and lung complaints.
Previous research on cells cultured in the lab has shown that certain compounds called flavones, found in the roots of this plant, not only have beneficial anti-viral and anti-oxidant effects, but they can also kill human cancers while leaving healthy cells untouched. In live animal models, these flavones have also halted tumour growth, offering hope that they may one day lead to effective cancer treatments, or even cures.
As a group of compounds, the flavones are relatively well understood. But the beneficial flavones found in Huang-Qin roots, such as wogonin and baicalin, are different: a missing – OH (hydroxyl) group in their chemical structure left scientists scratching their heads as to how they were made in the plant.
Work to unlock potential of plant life
The many uses of abundant but overlooked plants – from killing slugs to treating athlete’s foot – are being investigated by scientists at Bangor University.
Research into plant-based alternatives to products and ingredients currently derived from crude oil has found that ivy is just one of a range of plants with plenty of untapped potential.
Ivy, which grows abundantly in Wales, is being investigated by Bangor University’s BioComposites Centre at an Anglesey biorefinery for the fine chemicals and other valuable extracts and fibres which it contains.
The focus of the centre’s work is on finding new uses for valuable natural resources which are currently either completely ignored or thrown away.
Scientists have found that ivy could provide a number of extracts which could be used in areas ranging from personal products such as shampoo to horticulture and the food industry.
Development chemist Dr Dave Preskett said: “We’re not making the most of ivy; the plant has great potential.
“We’ve used ivy extract as a slug killer in place of slug pellets. Trials using it as a fungicide to treat potato blight – in place of oil-derived chemical sprays – proved very effective in protecting crops. The same extract also has great potential to be developed in products for treating dandruff and athlete’s foot. An oil produced from the berries is edible as, contrary to popular belief, ivy is not poisonous and has all the health-giving properties of olive oil but the more solid consistency of butter or lard.”
The centre provides the basic investigation into the compounds found in different plants and how they can be used, and also conducts specific contracted work for individual companies.
The new source of materials could also provide vital rural employment opportunities through local processing facilities known as biorefineries.
“The findings will help us feed a growing global population by speeding up the development of new varieties of wheat able to cope with the challenges faced by farmers worldwide.”
UK, German and US scientists decipher complex genetic code to create new tools for breeders and researchers across the world.
Scientists, including Professor Keith Edwards and Dr Gary Barker from the University of Bristol, have unlocked key components of the genetic code of one of the world’s most important crops. The first analysis of the complex and exceptionally large bread wheat genome, published today in Nature, is a major breakthrough in breeding wheat varieties that are more productive and better able to cope with disease, drought and other stresses that cause crop losses.
The identification of around 96,000 wheat genes, and insights into the links between them, lays strong foundations for accelerating wheat improvement through advanced molecular breeding and genetic engineering. The research contributes to directly improving food security by facilitating new approaches to wheat crop improvement that will accelerate the production of new wheat varieties and stimulate new research. The analysis comes just two years after UK researchers finished generating the sequence.
The project was led by Neil Hall, Mike Bevan, Keith Edwards, Klaus Mayer, from the University of Liverpool, the John Innes Centre, the University of Bristol, and the Institute of Bioinformatics and Systems Biology, Helmholtz-Zentrum, Munich, respectively, and Anthony Hall at the University of Liverpool. W. Richard McCombie at Cold Spring Harbor Laboratory, and Jan Dvorak at the Univerisity of California, Davis, led the US contribution to the project.
The team sifted through vast amounts of DNA sequence data, effectively translating the sequence into something that scientists and plant breeders can use effectively. All of their data and analyses were freely available to users world-wide.
Professor Keith Edwards said: “Since 1980, the rate of increase in wheat yields has declined. Analysis of the wheat genome sequence data provides a new and very powerful foundation for breeding future generations of wheat more quickly and more precisely, to help address this problem.”
The analysis is already being used in research funded by the Biotechnology and Biological Sciences Research Council (BBSRC) to introduce a wider range of genetic variation into commercial cultivars and make use of wild wheat’s untapped genetic reservoirs that could help improve tolerance to diseases and the effects of climate change. The wheat breeding community and seed suppliers have welcomed the research.