Science News Digest - 5 November 2012
In the news this week... new research explains why bananas may be one of the most important crops of the next century, experts predict which tree species may be the next victims of an invasive pathogen, evidence that exercise could help repair damaged heart tissue, a new study shows how fruit could be engineered to ripen at exactly the right time, and finally... how a flock of blackbirds unwittingly fell victim to alcohol poisoning.
Going bananas and saving the world
New research from CGIAR agricultural partnership has indicated that crops from the banana family could become a critical source of food for millions of people, as climate change impacts how well crops such as maize, wheat and potatoes are able to grow.
The group prepared the report in response to a request from the UN committee on world food security, and looked at the projected effects of climate change on 22 of what are currently the most important agricultural commodities.
Many crops from the Musa genus such as cassava were highlighted as food sources that could become much more important, as traditional crops struggle. Speaking to the BBC, Dr Philip Thornton, one of the researchers working on the report, explained that whilst crops such as bananas and plantains also have limiting factors, they may be a good substitute for stables such as the potato, in certain locations.
"It's not necessarily a silver bullet, but there may be places where as temperatures increase, bananas might be one option that small-holders could start to look at."
Wheat is likely to face a particular challenge in many parts of the developing world – as crops such as cotton, maize and soybeans offer higher profits, wheat is likely to be pushed to more marginal land. Here, it is more vulnerable to climate change induced stress. The report highlights that cassava may offer a useful alternative in these circumstances, as it is known to be tolerant to a range of climate stresses.
The cowpea plant, already a popular source of protein in part of sub-Saharan Africa, was also noted as a crop that showed particular promise in areas where traditional crops were negatively impacted by climate change. The plant is drought-tolerant, and prefers warmer weather, making it a good alternative to soya. The vines are also a suitable food-source for livestock.
Fears for other UK species at risk from invasive pathogens
On-going concern in the UK over invasive fungi infecting ash trees, has led to debate over the dangers of new waves of other invasive pathogens, with scientists predicting that the Scots pine, the national tree of Scotland, may be the next well-loved species that could fall victim. Two major pests that attack the species are already present in western Europe; the pine wood nematode, which causes pine wilt, and the fungus Fusarium circinatum, which causes the disease pitch canker.
Tree experts interviewed in the Guardian believe that both of these could imminently spread to Britain, and could cause a catastrophic level of decline, especially if they both emerged as a threat on our shores.
With its distinctive blue-green needles, and rich orange-red bark, Scots pine is both iconic, and an important source of timber. Thousands of hectares of pine trees have been felled in Portugal to try and contain the pine nematode there, however the disease has already spread to Spain. Northern Spain has also fallen victim to the pitch canker disease, seen in France and Portugal too.
The spread of these diseases may be blamed, in particular, on the huge number of plants and trees now traded within the EU. These often come with huge amounts of soil attached, which experts believe may be laden with pathogens. The increasing trade in exotic plants from Asia has been highlighted as a major cause of the rise in infections in Britain. Joan Webber, principal pathologist of Forest Research, the research agency of the Forestry Commission, explained that the UK had five major pest and pathogen outbreaks during the whole of the 20th Century. Since 2000, there has already been twice the number of pest outbreaks, than in the whole of the previous 100 years.
Experts are now looking at ways to limit future outbreaks, including quarantine, or the introduction of plant passports. Following the spread of ash dieback, the UK government is already facing a back-lash from foresters and nurseries, for failing to block ash importers sooner. The disease had now been confirmed at 52 locations in England and Scotland.
Study shows exercise could help repair heart damage
Stem cells have long been at the centre of much debate and research, and scientists have already proved their ability to produce new tissue after stimulation with growth factors. For the first time however, research has suggested that exercise may have a similar impact on the cells.
The research team responsible for the findings, at Liverpool John Moores University, carried out studies in healthy mice, giving them exercise equivalent to 30 minutes of running or cycling a day in humans. This resulted in 60% of their heart stem cells, which are usually dormant in adults, becoming active. The results published in the European Heart Journal, and discussed in the Telegraph, showed that after two weeks of this programme, the mice hearts showed a 7% increase in the cardiomyocites – the ‘beating’ cells in heart tissue.
The next steps for the research group, will be to study the impact of exercise on mice which have suffered heart attacks, to test whether they will show equal benefit. The research was funded by the British Heart Foundation.
New discovery about chloroplast biogenesis may help control ripening of fruit
Scientists from Leicester University may have discovered a technique with the potential to change the rate at which fruit ripens. In a study published in Science, researchers describe how they have identified the protein which changes the rate plant cells produce the bright pigments associated with the distinctive colour of ripened fruit. It also changes the way the cells develop, and could allow the ripening of crops to be speeded up, or delayed, depending on the need for an early or late harvest.
For the first time, the study showed that a regulatory system in plant cells, which dictates how proteins are broken down, also affects chloroplasts. These structures contain chlorophyll, the green pigment which absorbs sunlight and creates energy by the process of photosynthesis. It had previously been thought that the system only acted on central parts of the cell. However, these experiments on thale cress, showed how altering a specific gene could changes the speed the chloroplasts in the cells transformed into other structures, including those involved in fruit ripening.
Professor Paul Jarvis, leading the project, explained to the Telegraph that the mechanism may offer commercial crop growers the ability to ensure that fruit always ripens at the right time. The work is now due to be tested in a variety of other crops, such as tomatoes and bell peppers.
Beyond the potential in fruit production, the regulatory system is also responsible how quickly leaves age – meaning the system could also be manipulated to keep crops alive for longer.
Professor Douglas Kell, chief executive of the Biotechnology and Biological Sciences Research Council, who funded the research, is quoted in the Daily Mail: 'To ensure we have enough healthy, sustainable food for a growing population we need to find a range of novel solutions to challenges such as improving crop yields and reducing food waste. This research highlights one of the many ways in which science can help. The ripening process can happen quickly, and it can take just a few days for a fruit or vegetable to be considered inedible.
'This unavoidable process means big losses to both farmers and consumers. This discovery brings us one step closer to greater control over ripening so that we have greater flexibility for farmers when supplying produces in the best condition.'
Animal health experts called to examine the mysterious death of a group of young blackbirds found dead in Cumbria with significant trauma injuries, discovered that at least one the birds had a large amount of pure alcohol in its liver.
The scientists deduced that the injuries had in fact been sustained during flight, after the birds had all eaten berries from a nearby rowan tree. It is thought that fallen berries on the ground had fallen prey to a yeast infestation, causing fermentation and subsequently, alcohol production.
A further bird was rescued in the area, and staff at the wildlife sanctuary described it as unsteady on its feet, using its wings to support itself, and leaning on the walls of its enclosure.
A group of redwings was recorded as suffering a similar fate in 1999, after feeding on holly berries which had begun to ferment after a frost.