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Grandmothering as a familial structure is very rare among animals. Whales, elephants and some primates are the few species, besides humans, to actually adopt it. Image credit: Robert Pittman - NOAA

Based on the strong reactions that it provokes from people, it would be fair to say that mathematics has an image problem.

Maths is one of the few skillsets, unlike reading for example, that people are not embarrassed to admit they do not possess. Class room memories of daunting equations and fractions with no immediate resonance to the real world, scare people into declaring they are frankly, “rubbish at maths”.

In reality, mathematics underpins the world around us in more ways than we could ever imagine. Just by paying bills, measuring home improvements and making everyday decisions, people do maths, often without realising.

Our new Scienceblog series will tackle these preconceptions, highlighting the role that maths plays in shaping our understanding of science, nature and the world at large.

In the first of the series, Michael Bonsall, Professor of Mathematical Biology at the Oxford University Department of Zoology, discusses his research in population biology, and what it tells us about species evolution and why grandmothering is important to humans.

What is mathematical biology?

It is easy to get lost in the details and idiosyncrasies of biology. Understanding molecular structures and how systems work on a cellular level is important, but this alone will not tell us the whole science story. To achieve this we have to develop our insight and understanding more broadly, and use this to make predictions. Mathematics allows us to do this.

Just as we would develop an experiment to test a specific idea, we can use mathematical equations and models to help us delve into biological complexity. Mathematics has the unique power to give us insight in to the highly complex world of biology.  By using mathematical formulas to ask questions, we can test our assumptions. The language and techniques of mathematics allow us to determine if any predictions will stand up to rigorous experimental or observational challenge. If they do not, then our prediction has not accurately captured the biology. Even in this instance there is still something to be learned. When an assumption is proven wrong it still improves our understanding, because we can rule that particular view out, and move on to testing another.

By using mathematical formulas to ask questions, we can test our assumptions. The language and techniques of mathematics allow us to determine if any predictions will stand up to rigorous experimental or observational challenge. 

What science does this specialism enable – any studies that stand out, or that you are particularly proud of?

Developing a numerate approach to biology allows us to explore, what at face value, might be very different biologies. For instance, the dynamics of cells, the dynamics of diseases or the behaviour of animals. The specialism allows us to use a common framework to seek understanding. The studies that stand out in my mind are those where we can develop a mathematical approach to a problem, and then challenge it with rigorous, quality experiments and/or observation. This doesn’t have to happen in the same piece of work but working to achieve a greater understanding is critical to moving the science forward.

You recently published a paper: ‘Evolutionary stability and the rarity of grandmothering’, what was the reasoning behind it?

Grandmothering as a familial structure is very rare among animals. Whales, elephants and some primates are the few species, besides humans, to actually adopt it. In this particular study we took some very simple mathematical ideas and asked why this is the case.

Evolution predicts that for individuals to serve their purpose they should maximise their reproductive output, and have lots of offspring. For them to have a post-reproductive period, and to stop having babies, so that they can care for grandchildren for instance, there has to be a clearly identified benefit.

We developed a formula that asked why grandmothering is so rare in animals, testing its evolutionary benefits and disadvantages, compared to other familial systems, like parental care and co-operative breeding for instance, (When adults in a group team up to care for offspring). We compared the benefit of each strategy and assessed which gives the better outcomes.

What did the findings reveal about the rarity of grandmothering and why so few species live in this way?

Our maths revealed that a very narrow and specific range of conditions are needed to allow a grandmothering strategy to persist and be useful to animals. The evolutionary benefits of grandmothering depend on two things: the number of grandchildren that must be cared for, and the length of the post-reproductive period. If the post-reproductive period is less than the weaning period (the time it takes to rear infants) then grandmothers would die before infants are reared to independence.

We made the mathematical prediction that for grandmothering to be evolutionary feasible, with very short post-reproductive periods it is necessary to rear lots of grandchildren. But if this post-reproductive period is short, not many (or any) would survive. Species with shorter life spans, like fish, insects and meerkats for instance, simply don’t have the time to do it and focus on parental-care. Evolution has not given them the capability to grandparent, and their time is better spent breeding and having as many offspring as they can. By contrast long-lived animals like whales and elephants have the time to breed their own offspring, grandparent that offspring and even to great-grandparent the next generation.

We developed a formula that asked why grandmothering is so rare in animals, testing its evolutionary benefits and disadvantages, compared to other familial systems, like parental care and co-operative breeding for instance, (When adults in a group team up to care for offspring). 

How do you plan to build on this work?

Although grandparenting isn’t a familial strategy that many species are able to adopt, it is in fact the strongest. Compared to parental-care and co-operative breeding, grandparenting has a stronger evolutionary benefit – as it ensures future reproductive success of offspring and grand-offspring – giving a stronger generational gene pool.

Moving forward we would like to test mathematical theories to work out if it is possible for species to evolve from one familial strategy to another and reap the benefits. Currently for the majority of species rearing grandchildren instead of having their own offspring is not a worthwhile trade-off.

What are the biggest challenges?

Ensuring that the mathematical sciences has relevance to biology. Biology is often thought to lack quantitative rigour. This would be wrong. The challenge is to show how the mathematical sciences can be relevant to, and help us to answer critical questions in biology. This will continue to be a challenge but will yield unique insights along the way in unravelling biology.
 
 What do you like most about your field?

So many things. Firstly, the people. I work with a lot of very smart people, who I look forward to seeing each day. I also get to think about biology and look at it through a mathematical lens. Finally I think the specialism allows us to do fantastic science that has the potential to improve the world.

Is there any single mathematical biology problem that you would like to solve?
 
Developing a robust method to combine with biological processes that operate on different time scales - as this would have so many valuable, and to use one of my favourite words, neat, applications to our work.

Why did you decide to specialise in this area?

Because of the perspective that we can gain from it and because I love biology and maths. Unpicking the complexities of the natural world with maths and then challenging this maths with observations and experiments is super neat. And I can do (some of this) while eating ice-cream!

‘Evolutionary stability and the rarity of grandmothering’ Jared M.Field and Michael B.Bonsall is available to download from the science journal Ecology and Evolution.

Image credit: Shutterstock

As the much anticipated Conservation Optimism Summit begins, Scienceblog talks to Professor EJ Milner-Gulland, Tasso Laventis Professor of Biodiversity in Oxford’s Department of Zoology. Co-creator of this landmark movement, she shares how she is working to protect some of wildlife’s most endangered species, what we can all do to be more environmentally conscious and why she has had enough of the doom and gloom around nature.

What was the inspiration behind the Conservation Optimism Summit?

 The idea came about when I attended a lecture given by the great coral reef biologist Professor Nancy Knowlton, who founded the #OceanOptimism initiative. That campaign has done a fantastic job of highlighting positive stories about ocean conservation, and spreading them far and wide via social media.

Highlighting the challenges we face, rather than showing the progress that is being made to tackle them, makes people feel like there is nothing that they can do to help, when it really isn’t the case. 

It got me thinking about how much we conservationists shoot ourselves in the foot by focusing on the negative. Highlighting the challenges we face, rather than showing the progress that is being made to tackle them, makes people feel like there is nothing that they can do to help, when it really isn’t the case. There is a lot to be proud of in conservation, and we need to be better at sharing it.

Once I had the idea in mind, I thought about how exciting it would be to have a Conservation Optimism event linked to the Earth Day events that people like Nancy Knowlton were also planning, and about the potentially powerful effect we could have in changing the conversation within conservation.

How does the format of the summit differ from other environmental campaigns?

Conservation Optimism is intended for everyone. Environmentalists, scientists, policy makers, academics, children – people in general. Our initiative encourages a global, collaborative way of thinking. While the only professional summit, specifically for conservationists, is taking place at Dulwich College, London, there are public events taking place all over the world. The flagship Earth Optimism event is organised by the Smithsonian Institute in Washington DC, but there are also events in Cambridge and elsewhere, so it is possible for people to get involved anywhere. My hope is that everybody who comes along not only enjoys themselves but comes away with a renewed commitment to protecting the natural world and a set of actions that they can implement themselves to make a difference.

Professor Milner-Gulland pictured conducting field research, with a saiga antelope.Image credit: EJ Milner-Gulland

The summit has been a culmination of months of planning and work, how do you plan to build on the initiative’s success in the future?

After the event we will sit down and analyse how people responded to the programme, did it inspire them or change their thinking or actions? Hopefully it will become an annual event, and more and more people around the world will get involved over time. The movement’s website will continue, and be updated with highlights from the summit and ideas to encourage people to stay connected with the Optimism movement.

What would you like the legacy of Conservation Optimism to be?

I hope conservationists will think hard about the way in which we approach our work, how we present it, and how we can be more forward-thinking and positive. We need to stop focusing on winning battles and collaborate to win the war. That begins and ends with the public working with us. We have to connect with them in a way that makes them feel that they can do something to change things.

Starting a community initiative, checking out local wildlife trust websites for news about public events, or simply replacing plastic bags with bags for life and plastic bottles for refillable ones, all helps. Plastic pollution is a huge threat to our oceans, with tragic consequences for wildlife. In all parts of the world, whether it's the UK or elsewhere, people can play a more active role in conserving their local wildlife. No matter where we live, every one of us can do more to protect the environment and get actively involved in conservation.

What’s next for you?

I’m going to Colombia in a couple of months to present at the International Congress on Conservation Biology and am looking forward to connecting with international colleagues and working how we can collaborate to tackle the challenges in our field.

What are the biggest challenges that you face in your work?

As scientists who are passionate about nature, it is challenging to make our work relevant to people's daily lives. Scientific language can be alienating; we need to bring nature to life in an exciting way that makes conservation interesting to people.

In today’s society everything we do as scientists has to have a real world impact to make it onto the agenda for governments and funders. People want to know ‘why should I care about this?’ and if we want to change the world for the better, we have to make a strong case that speaks to their needs and priorities.

Image credit: ShutterstockProfessor Milner-Gulland was inspired to start Conservation Optimism, after attending a lecture given by the coral reef biologist Professor Nancy Knowlton, who founded the #OceanOptimism initiative. Image credit: Shutterstock

And the opportunities that you enjoy the most?

For me it is the feeling that you are making a difference, changing the way people think about the natural world. I enjoy working with young people from around the world who are really passionate about conservation.

Starting a community initiative, checking out local wildlife trust websites for news about public events, or simply replacing plastic bags with bags for life and plastic bottles for refillable ones, all helps. Plastic pollution is a huge threat to our oceans, with tragic consequences for wildlife.

What achievement are you most proud of?

My ecological research in Central Asia with the saiga antelope. I’ve stuck with it for more than 25 years, through a time when uncontrolled poaching catapulted the species towards the brink of extinction,to now, when saiga numbers are increasing, and there is hope again. My research has played a part in in getting us to this point, and although it has not been without its challenges, I am very proud to have been involved.

Aside from Conservation Optimism, what other projects are you working on at the moment?

One exciting new initiative is the Oxford Martin’s School Illegal Wildlife Trade programme. The illegal and unsustainable trade in wildlife is a major threat to global biodiversity. I am working to understand the drivers and motivations of wildlife consumers to work out how we can change this behaviour.

Do you think there are any unique challenges to being a woman in science?

Balancing family time with your passion for research is a constant challenge. Fortunately, universities actively try to support people to achieve this, much more so than in many other jobs. It is important for people to realise that it doesn’t have to be all or nothing. It is possible to do well in science and have a life outside of your work.

Are there any changes that can be made to make this balance easier?

A lot of the problem comes from young people being employed on short term contracts before they achieve permanent positions, and that makes it hard to plan your life. Once you have the security of a permanent position there are lots of positive initiatives in place to support people who have family commitments. But making that step is really hard. Research grants like the Dorothy Hodgkin Fellowship which support people coming back into academia after a career break, are fantastic. These allow people to have research time to build their career when coming back, and make it easier to balance their various commitments.

How did you come to be a scientist?

I was raised in the British countryside, so grew up surrounded by nature and spent lots of time outdoors. I have always found biology fascinating, and was also fortunate to have a fantastic teacher who inspired me. Coming from a family who were keen to share their love and knowledge of nature with me was also an inspiration.

One piece of advice that you would give to other would be scientists entering the field?

Do what you love, rather than compromising on doing research that you feel you ought to do because it's fashionable or where the money is.

Image credit: EJ Milner-GullandProfessor Milner-Gulland pictured rowing, with her family

Credit: Oxford University

Women in science series: Engineering a difference

Lanisha Butterfield | 3 Apr 2017

Many female scientists now have inspiring stories to tell, but all the science disciplines still need to make progress on gender equality. With the lowest percentage of female professionals of all the STEM areas (9% in UK universities), engineering is one of the most  scrutinised specialisms.

As a Canadian woman of South Asian heritage, Dr Priyanka Dhopade, Senior Research Associate at Oxford University’s Osney Thermo-Fluid Laboratory, is breaking down barriers in more ways than one. She talked to Scienceblog about her journey so far and how she is using her own experience coming from a minority background to create a brighter future for female engineers to come.

What does your work involve?

Most of my work is in partnership with Rolls-Royce plc, and focuses on the aerodynamics of jet engines, specifically controlling the temperature inside the engine. Jet engines are designed to operate at extremely high temperatures and pressures to be efficient. This means that some parts of the engine are exposed to temperatures higher than the melting points of those parts. This requires some creative cooling methods e.g. internally cooling the turbine blades using a complicated network of passages. My research focuses on finding the novel cooling methods, preventing overheating but at the same time not making it too cool that you decrease its thrust or efficiency.

Dr Priyanka Dhopade is an aerodynamics engineer Credit: Dr Priyanka DhopadeDr Priyanka Dhopade is an aerodynamics engineer Credit: Dr Priyanka Dhopade

What is your take on diversity in general at Oxford?

I think Oxford has come a long way, but there is still more to be done. It’s a diverse and inclusive environment for research and collaboration and I work with people from various ethnicities on a daily basis. However, given the historical context, I do recognise that there is still this perception that Oxford isn't open to everyone. It can be difficult to change these perceptions and it takes time.

The Diversifying Oxford Portraits initiative is a great example of a tangible change that can help. Outreach programs targeting BME groups and communities that are outside the "Oxbridge" network can also help. The University can only benefit from diversity in all forms - ethnicity, class, gender, disability and sexual orientation. Given the current political climate, I think it's important for educational institutions, especially those as prestigious as Oxford, to set an example of an open, diverse and inclusive community.  

The University can only benefit from diversity in all forms - ethnicity, class, gender, disability and sexual orientation. Given the current political climate, I think it's important for educational institutions, especially those as prestigious as Oxford, to set an example of an open, diverse and inclusive community. 

What has it been like being a woman studying, working and now teaching engineering?

I have studied and worked in engineering in Canada, Australia and the UK, and the experience has been fairly similar, I have always been in a minority in my industry. After a while that gets hard to ignore. I don’t think it is so much a reflection on the universities themselves, but more to do with the level of my position within them. As my career has progressed, it has become more and more noticeable that I am in a minority in my field.

Credit: Dr DhopadeDr Priyanka Dhopade coordinates the Women in Engineering at Oxford group, which organises talks, social events and other networking activities for women in the field. Credit: Dr Dhopade

How has it become more noticeable?

As an undergraduate in Canada, I never felt or experienced discrimination. If anything, it was a very positive time for me. I worked hard to really understand the material, and helped other students along the way. When studying for my PHD I was one of the only females in the research group and now as a senior researcher I am the only female - in a group of eighty personnel. Numbers like that are hard to ignore, and you become more aware and frustrated by these issues.

I coordinate the Women in Engineering Oxford group and think I am more of a feminist and an advocate for women in STEM now, than I ever was before, because of my own journey. After a while you just start to think ‘this is not right, I should not be the only woman here.’

Do the women in the group have similar experiences?

There is real camaraderie between the women in my field, which is something I never expected. We are all tied by a common bond, and so understand the issues and support each other. I have made so many female friends across STEM and other PHD areas because of what I do, probably more than I have ever had. It's been great to watch the Women in Engineering at Oxford group, initially created to support the Athena SWAN initiative, grow over the last few years, as more women have joined the research team. Though we still have some work to do to help them progress to high level positions.

Credit: Dr Priyanka DhopadeDr Priyanka Dhopade is an aerodynamics engineer, who works in collaboration with manufacturers like Rolls-Royce plc. Her research focuses on finding cooling methods for jet engines that strike a balance between preventing overheating and not making it so cool, that it impacts thrust and efficiency. Credit: Dr Priyanka Dhopade

How do you think these issues and the general imbalance of women working in engineering can be addressed?

It has to be tackled collaboratively by employers and on a policy level. Maternity leave policies are set by the government but have a major impact on how employers view family responsibilities. I know women who have been asked in interviews, directly, if they plan to have children, and if they answer yes, they are seen as not being serious about their careers. I feel that the government sets the tone, and needs to make parental leave a shared responsibility, (as it is in Scandinavia for example). If both men and women had the option of appropriate parental leave it would be seen more as a natural progression of life for those that choose to do so, not just something that women want. I think things are moving in the right direction, but it is a long process.

Unconscious bias is a big issue that does not get much attention. It is difficult to get people to challenge and face up to their own implicit biases, everyone has them, but are rarely willing to admit to them. There is already some great training underway, like the Royal Academy of Engineering and Royal Society of Science, who are rolling out unconscious bias recruitment programmes. But more is needed to encourage panellists to be open minded, particularly at higher levels of academia.

Unconscious bias is a big issue that does not get much attention. It is difficult to get people to challenge and face up to their own implicit biases, everyone has them, but are rarely willing to admit to them.

Speaking to senior academics at Oxford, I know that the University wants to hire more women, but they just aren’t getting the applications. I’m not entirely sure why that is, but I think confidence has a lot to do with it. Having been in their shoes, without my PHD supervisor recommending me I probably wouldn’t have applied myself. There are not many women in top tier engineering research positions and for that to change there has to be some degree of head hunting for female scientists as well.

How would you describe your experience of Oxford?

I’ve been at Oxford for four, very positive years. We work closely with partner organisations, which means I get to have direct impact on Rolls-Royce plc next generation technology, which is so rewarding.

Credit: Dr DhopadeDr Dhopade has a passion for astronomy, and in her spare time takes in some spectacular views of the moon, with her telescope from her balcony.

What is the biggest challenge in your job?

The biggest challenge is also the biggest blessing; working directly with sponsors. Large external organisations work to their own deadlines, so we have to adapt our working styles and be more flexible.

Where do you see yourself in 10 years?

In academia, continuing my research career at Oxford hopefully. My work has the potential to significantly reduce the environmental impact of civil aviation, which, as air passenger travel continues to rise, is critical. More efficient engines consume less fuel and emit less greenhouse gases.  I also want to get more involved in conveying the importance of engineering research to the general public.

Did you always want to be an engineer?

Growing up in a South Asian family, the cultural connotations of a career in science were very positive and encouraged, which I think isn’t always the case in the West. STEM fields were seen as stable, financially rewarding professions for boys and girls. My Dad is an engineer too, so I am lucky to have supportive parents who understand the field.

One of my earliest role models was Roberta Bondar, the first Canadian woman in space, and I had a signed poster of her on my wall growing up. Every time I looked at it, I’d get inspired and think; ‘if she can do it, so can I!’ Female role models play such an important role in a young girl’s life.

Engineering is mentally taxing, how do you like to unwind?
I love travelling and also have a telescope that I am always looking for an opportunity to use (even though Britain's climate is largely uncooperative in this aspect!) and so far, I've seen some spectacular views of the moon and sun from my balcony.

What is your favourite thing about your job?

Working with so many smart people is so inspiring. I feel like I am getting smarter everyday just from being around them.

Credit:  A/Prof Andrew Neely Dr Dhopade is a an advocate for STEM, and involved in community outreach, conveying the importance of engineering research to the general public.

Monitoring the emergence of infectious diseases

In a guest blog, Professor Stephen Baker from the Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, explains the importance of monitoring the emergence of infectious diseases in Asia.

Zoonotic diseases that pass from animal to human are an international public health problem regardless of location – being infected with Campylobacter from eating undercooked chicken in the UK is not uncommon, for example – but in lower-income countries the opportunities for such pathogens to enter the food chain are amplified.

Where I currently work in Vietnam, and across the region, humans have a very different way of interacting with animals being bred for food than would be familiar to those in the UK. If one were to travel to the Mekong Delta region (in the south of Vietnam) it would not be uncommon to see people who keep a large variety of farm animals in, or in close proximity to, their houses. It comes as little surprise that in a country where raw pig blood and pig uterus are commonly consumed, the number one cause of bacterial meningitis is Streptococcus suis, a colonising bacterium of pigs.

The major problem of researching emerging infections is predicting how they arise and how we respond to them once they do.

Given the complexity of zoonotic disease emergence and transmission, it is very rare that an outbreak can be traced back to the first identified human or animal case – known as the ‘index case’ and this remains a substantial challenge. A lack of effective health and surveillance infrastructures in many lower income countries compounds this issue, as we are wholly reliant on individuals entering the healthcare system and getting diagnosed, which seldom happens.

The ideal scenario is that we can identify new pathogens with zoonotic potential in animals prior to them spilling over into humans. However, if we cannot achieve this we need to be aware of their existence and be able to respond by treating people effectively once they are infected. This means rapidly identifying patients with a particular infection, assessing the severity of their condition and diagnosing the agent. Therefore, having sentinel hospitals with well-trained clinical staff, good diagnostics and microbiology facilities is the best opportunity we are going to have to detect diseases.

The most recent example of this is a case of Trypanosoma evansi infection – a protozoan disease of animals and, rarely, humans – that we identified in a woman attending our hospital with an atypical disease presentation. Ultimately, we were able to trace this infection back to her cutting herself when butchering a buffalo in her family house during New Year celebrations – this was the first reported human case of T. evansi in Southeast Asia. Our ability to interact with animal health authorities permitted access to sampling bovines in the proximity of the patient’s house. We found a very high prevalence of the parasite in the blood of cattle and buffalo close to where the woman lived, highlighting a new zoonotic infection in the region and likely a sustained risk.

Diagnostic information has also been vital in data we published detailing an outbreak of fluoroquinolone-resistant Shigella sonnei. The reason we found this organism was that one of my clinical colleagues was culturing organisms from children with severe diarrhoeal disease, and realised that these samples had come from children who had been admitted to hospital with a more persistent form of the infection, and several appeared to relapse with the same syndrome. When we investigated the antimicrobial susceptibility profile of the isolated Shigella, we observed that the bacteria were highly resistant to fluoroquinolones – the antimicrobials that are used routinely to treat this infection in Vietnam (and indeed globally). We then conducted more clinical and laboratory investigations and found more cases in Vietnam and further afield. Through genome sequencing and a group of international collaborators, we could accurately piece together the emergence of this novel strain into Vietnam, other parts of Asia, Europe and Australia.

These finding were largely serendipitous, but if you are not looking then you cannot find. Unfortunately, this approach is not a long-term strategy for monitoring and preventing the emergence of such pathogens. Sadly, the infrastructure improvements and long-term health studies that are needed to achieve a more sustainable model in lower income countries are an expensive undertaking, but without them healthcare improvements and changes to infectious disease policy will be difficult to achieve.

Vietnam has changed beyond recognition since my arrival in 2007. Huge economic investment and political stability has had positive effects on healthcare in the country, and across the region. However, many challenges remain; a growing population, increasing demands for animal protein and the looming cloud of antimicrobial resistance in everyday pathogens suggest that Southeast Asia will continue to be a key region in driving global health security.

The full article, ‘Emerging infectious diseases in Asia,’ appeared in the latest edition of the Microbiology Society’s quarterly magazine, Microbiology Today.

Flooded rice field. Image credit: Shutterstock

Scientists have long understood how oxygen deprivation can affect animals and even bacteria, but until recently very little was known about how plants react to hypoxia (low oxygen). A new research collaboration between Oxford University and the Leibniz Institute for Plant Biochemistry, published this week in Nature Communications, has answered some of these questions and shed light on how understanding these reactions could improve food security. Dr Emily Flashman, the lead author of the study and a research lecturer at Oxford’s Chemistry Department, breaks down the key findings:

Why is this study so important?

Most living things need oxygen to survive, including plants but flooding is a major threat to agriculture and vegetation. A plant's oxygen levels are jeopardised during a flood, and they basically can't breathe. To protect themselves from flooding and survive longer, plants have a built-in stress response survival strategy, which re-configures their metabolism and supports them to generate more energy.

Scientists knew about this stress response, but they didn’t know exactly how it was controlled. Our research underpins not only an understanding of how plants respond to loss of oxygen, but also how this response could be manipulated to protect them long term. With climate change of increased prevalence in today’s society, flooding is a constant source of concern, so it is even more important for us to understand how hypoxia affects plants and crops, so that we can find new ways to preserve and protect them from it. Manipulating the enzymes involved in the process may help us to cultivate new crops and even to weather-proof them.

How does this reaction affect them?

When oxygen is in short supply a plant’s stress response effectively shuts down its metabolism, and activates an alternative pathway that allows it to live for a short amount of time, with reduced oxygen. During this time the plant has much less energy, but is still able to survive and function on a basic level. Much like when someone holds their breath underwater, their oxygen reserves allow them to survive for a short amount of time, even though they cannot breathe in fresh oxygen.

Local floodingImage copyright: OU

Our research underpins not only an understanding of how plants respond to loss of oxygen, but also how this response could be manipulated to protect them long term. Manipulating the enzymes involved in the process may help us to cultivate new crops and even to weather-proof them against climate change.

What was the aim of your research?

We wanted to analyse this process, and understand how the enzymes that trigger it work. Once you know this information, you can then work out how to inhibit the enzymes and control the flood response pathway, and in doing so, keep the plant alive for longer. The overall aim being to genetically modify crops to make them flood tolerant. Understanding how these processes work is the first step in achieving this. Until now the molecular details of the plant stress response to hypoxia were not proven, but our research changes this.

Scientists understood that a plant’s response to hypoxia is controlled by ERF transcription factors, proteins which trigger changes in gene expression. In turn, the stability of the ERFs is controlled in an oxygen dependent manner by a set of enzymes, the Plant Cysteine Oxidases (PCOs). The PCOs speed up the break down (degradation) of these transcription factors, via one of the cell’s protein removal and recycling systems, called the proteasome. 

Crucially, our research showed how PCOs use oxygen to work, and how this allows the ERFs to be recognised by the next step of the degradation pathway. Thus the whole pathway needs molecular oxygen to work. So in times of regular oxygen supply, the ERFs are degraded before they reach the cell nucleus and before they can activate the stress response genes. However, when oxygen is limited, as is the case during flooding, the PCOs cannot work, efficiently, so the ERFs will not be flagged for degradation and can activate the hypoxic stress response required for the plant to survive.

With climate change causing increasingly frequent flooding events worldwide, understanding how crops respond to flooding is important, in order to control or manipulate the process. 

How can the findings be used to improve food security?

With climate change resulting in increasingly frequent flooding events worldwide, understanding how crops respond to flooding is important, in order to control or manipulate the process. Our research supports the understanding of this response on a molecular level – down to the role played by individual enzymes in the process. Stabilising the ERF transcription factors has been shown to enhance flood tolerance, so the targeted inactivation of the enzymes that regulate its stability may assist in cultivating crops that are able to withstand flooding longer and more efficiently.

 How can the findings be built on in the future?

 Now we understand what the enzymes do, we are looking further into the details of their structure and mechanism to understand precisely how they work. This will help us target the most effective way to manipulate them to artificially inhibit their activity and enhance ERF stability, first using the isolated components of the pathway before testing in plants. 

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