What would a world without wheat be like? | 91TV
Transcript
- Thank you very much, Jane, for that very kind introduction. Firstly, of course, I'd like
- to start by thanking the Royal Society and the committee for this fantastic award. It really is
- a great honour to receive the Rosalind Franklin Award and to have this opportunity through this
- award this evening to share with you this lecture. Today, I want to focus on how we tackle plant
- disease outbreaks or epidemics, as just like you and I, plants are attacked by diseases,
- and they're caused by all sorts of things right through from bacteria and viruses through to
- fuzzy fungi, and this is because plants get sick, too. Tonight, I'd like to focus on one particular
- fungal disease of plants and take you on a journey on the trail of this perpetual serial killer that,
- since the dawn of agriculture, has threatened one of our oldest and most precious food crops known
- as wheat. So wheat is one of the top-three staple crops grown worldwide, and its role in the human
- diet can be traced back to over 10,000 years ago. Wheat cereal grains are also exceptionally
- versatile, and we create more foodstuffs such as bread, cake, pasta, and even beer from wheat
- grains than any other grain. It's cultivated on more land area than any other crop, and protecting
- and enhancing wheat productivity over the past 10,000 years really helped to contribute to the
- development of modern society, but sadly, both ancient and modern wheat crops are ravaged every
- year by a dangerous serial killer known as the wheat rusts. So these wheat rusts, they destroy
- every year, globally, around 15 million tonnes of wheat, which is an annual loss of around US$2.9
- billion. This sounds like a really big number, and indeed, this is quite a big number, because if
- we now put that into context, the amount of wheat destroyed by these serial killers, if we took all
- of that wheat and we just used it to bake bread, this would be enough wheat to bake 25 billion
- loaves of bread, and enough bread to satisfy the annual consumption of 425 million people,
- or even over half the population of Europe. As we look to the future, over just the next
- ten years, it's thought that wheat consumption is going to increase by around 11, and so you
- can see that curtailing the trail of destruction caused by these serial killers could really help
- to close that missing production gap and ensure that we can feed our expanding population. So
- how do we outsmart a serial killer and protect our grain harvests, both today and for future
- generations to come? Well, here, we can actually turn to the pillars of disease management that we
- all became so very familiar with during the COVID pandemic, and underpin human health governance,
- a framework that equally applies to human, animal and plant health. The first step, of course,
- is to prevent disease outbreaks from occurring. The way we do that is to make sure that we have
- a really good understanding of all the biological and environmental risk factors that can lead to
- a disease outbreak. Then, of course, we need really good detection mechanisms in
- place to make sure that we can rapidly detect the disease as soon as it occurs, and then, finally,
- have effective response measures in place to address these threats once they start to spread.
- So now, if we firstly consider the prevention of disease epidemics, I think here, to firstly
- appreciate just how far human knowledge has come regarding our understanding of what causes plant
- diseases, we have to turn our attention to our ancient counterparts and their reliance on the
- supernatural, religion and natural philosophy that underpinned our understanding of plant disease,
- outbreaks until very recent human history. So now, if we take a journey back into the ancient world,
- in the ancient world, the Greeks and the Romans, they had the rust gods, and these
- acted like supernatural plant pathologists. For the Greeks, they had the Apollo of rust,
- and in ancient Rome they had the rust god, Robigus, and each year they would worship
- these rust gods. In ancient Rome they also had a festival known as the Robigalia Festival, that was
- thought to have been established around 700 BC, and it was celebrated each year on 25th April.
- During that celebration, they would sacrifice red-haired animals to appease the rust god,
- Robigus, and hopefully then protect their crops from these wheat rusts and ensure a bountiful
- harvest, but unfortunately, this strategy didn't really work. So the serial killers then continued
- to destroy wheat production, and that then drew the attention of many ancient philosophers,
- including, of course, the famous philosopher Aristotle, who was one of the first scholars to
- articulate, or at least recorded to articulate, the theory around spontaneous generation,
- where he believed that non-living beings created living beings. During this time he also talked
- about the wheat rusts, and he thought the disease he saw out there in the fields was created from
- warm vapours that spontaneously turned into the disease in the field. The facts we know today,
- that these diseases are caused by fungal organisms, is something that these early
- philosophers just couldn't even comprehend. Then, over the next few centuries, understanding
- around what caused disease really changed very gradually, until the Age of Enlightenment in the
- 18th century, and this is when, during the 1700s, the first scientific name was given to these wheat
- rusts, and they were called Puccinia. Puccinia is a term that we still use as scientists today,
- but even if you look at the definition where they recorded this first scientific name, they didn't
- record it as a fungus. They actually recorded it as a plant, a plant that infected plants,
- and it was only until the fantastic work of Heinrich Anton de Bary,
- conducting experimental work, to show that finally we would know that parasitic fungi
- do actually cause plant disease. Heinrich Anton de Bary also, then, went on and resolved many
- of the complexities of the infection cycles of many of these complex fungal organisms, but this
- was a monumental moment for plant pathology, just establishing that fungi can cause plant disease.
- Today, we now know that these wheat rusts, they aren't just one flavour. We actually have three
- different fungi that we term the wheat rusts, and those three different fungi are very closely
- related to one another, but they actually cause three distinct diseases. They cause leaf rust,
- stem rust, and yellow rust, all diseases of wheat, and for this part of the lecture, I'd just like to
- focus on wheat stem rust. I'd also like to return to the fantastic work of Henrich Anton de Bary, in
- deciphering the complexity and the beauty of the infection cycle of this wheat stem rust fungus.
- This is a very complex infection cycle. Actually, this fungus is able to infect not just wheat,
- but also another unrelated host plant, and so it infects both wheat and also this barberry plant
- and many different types of barberry. The one that I'm showing here is known as common barberry,
- and it's during the summer months that this fungus likes to infect wheat plants.
- You can see here on the stem of this plant, this orangey area. This is typical of stem
- rust infection of this plant, and if we then look in at these particular pustules that have formed
- on the surface of the stem, you can see that they're filled with these ball-like structures,
- these spiky ball-like structures, and these are the spores of this fungus. These spores
- are created and they fall out of these pustule structures, and then they blow on the wind,
- moving the disease from one wheat plant to the next. Then, at the end of the summer, of course,
- our farmers go out into our wheat fields and they harvest this crop. At this point, of course, the
- fungus was really enjoying its tasty meal. It's not very happy that the wheat plants are now being
- harvested, and so what does this fungus do? Well, it changes its form and it goes to sleep, and it
- sleeps out there on the stubble that's left behind in the wheat fields, or it sleeps in the edges of
- the field margins on grasses, and it sleeps there happily throughout the winter months in the cold
- temperatures that we see here in the UK. It's only that it awakens in the spring at the first
- flush of leaves that occur on the barberry bush. Then this fungus awakens, and then it infects
- this barberry bush, and you can see here this orange-type area, which is typical symptoms
- of stem rust infection on the barberry plant. Again, now, if we zoom-in to that structure on
- the underside of this leaf, you can see it's full of these tube-like structures
- and these tube-like structures, once again they're filled with those balls. but this time different
- types of balls. Those little balls are their spores again, and those spores, they don't go on
- to reinfect the barberry bush - that isn't their purpose - instead, they're created to spread the
- disease back into the wheat crop, and these spores move into neighbouring wheat crops and spread the
- disease further. The fact that barberry bushes can play such an important role in the life cycle,
- or the infection cycle, of this wheat stem rust fungus, meant that throughout history
- there was a lot of legislation and restrictions, and exclusion campaigns to remove barberries from
- great swathes of different countries, to try to get it out of wheat-growing areas. So we
- saw legislation introduced in many countries in Europe, also in America and in Canada.
- One of the campaigns that was really well documented is the campaign that occurred in North
- America, and these are just some of the leaflets and posters that accompanied that campaign for
- barberry removal. That campaign began in 1918, and it went on into the 1970s, and if we just look at
- the first 15 years of that campaign, in 15 years they ripped out over 18 million barberry bushes.
- This was a huge success for disease prevention, as it meant then that they didn't have that local
- source of spores present that could spread disease into the neighbouring wheat fields,
- and so it really did help to dampen down the scale of disease outbreaks. Here in the UK,
- and in particular in England, our farmers were even more proactive as they started ripping out
- these barberry bushes over 300 years ago. You have to remember, 300 years ago is before the
- work of Henrich Anton de Bary, showing that the same fungus could infect the barberry plants and
- the cereal crop, and so these farmers were far ahead of the scientists of the time,
- because they just knew that when they went out into the field, they could see that their wheat
- crop was infected, and if they had a barberry bush next door that looked infected, it was more
- likely the crop also would get infected. As Stakman says in this article, 'Well,
- they just showed their good sense and they ripped out all these bushes,' but of course,
- here in the UK we actually used to have quite a big problem with wheat stem rust. We used
- to have frequent epidemics of wheat stem rust, but the last epidemic of this disease occurred
- now back in 1955, and because our farmers were so proactive, we didn't have any legislation to
- restrict planting, because our farmers were so good at pulling out these bushes. That means,
- of course, that now that this fungus is a distant memory for so many people here in the UK,
- the number of these bushes has slowly started to increase over time. Also, now, sadly,
- the situation has changed, as back in 2013, we then saw wheat stem rust return to the UK,
- when we recorded the first incidence of wheat stem rust in over 60 years. Also. in 2013,
- many of our colleagues across Western Europe also reported wheat stem rust in their wheat fields.
- In some of these cases the infections were quite severe, such as the outbreak in Sicily damaging
- tens of thousands of hectares of crops, and many of our neighbouring countries in Western Europe,
- this was the first time that they'd seen the disease in their wheat fields for many, many
- decades. Here in the UK we were very, very lucky because, although we saw the disease in our fields
- in 2013, it was only one infected plant that was recorded. So this isn't a really big problem for
- agriculture. It is only one infected plant, but it was rather significant, because it was the
- first time that we'd seen wheat stem rust since that last epidemic back in 1955. Then, over the
- next years, of course, the number of plants that were recorded as being infected slowly started to
- increase, but up until 2021, the number of plants each year that were infected was just at one or
- two locations, and just a small handful of plants. Unfortunately, that situation then changed this
- summer, when we saw the most widespread outbreak of wheat stem rust here in the UK than we'd seen
- since 1955, the last epidemic of this wheat stem rust fungus. This is just an image of one of the
- fields that was infected. During 2022, we were able to show that there was infection across
- 12 different English counties and Wales, and so really there were infections in many locations
- across the UK. The situation had clearly changed since 2013 where we found just one infected plant.
- We now had infections across 12 different English counties and Wales, but luckily, in all of these
- cases, really the infections were quite limited. Again, it was just a few plants up to the scale
- of a plot that was infected by wheat stem rust. Also, through discussions with colleagues, it's
- clear that where people were using fungicides, so chemical applications, to dampen down disease from
- other pathogens, then this was very effective at keeping the wheat stem rust in check,
- and any wheat plants that were treated by fungicides didn't get infected. It was only
- those that hadn't been treated that were infected. But with the number of plants slowly increasing
- that are infected by wheat stem rust over the past few years, of course, the question then comes,
- well, what would happen if wheat stem rust did get re-established here in the UK? Would this
- actually be a big problem for agriculture? So to address that, we then decided to work with Willem
- Boshoff at the University of the Free State in South Africa, where he took many of the wheat
- varieties that our farmers grow. We have to remember that wheat here is not uniform. We
- have lots of different types of wheat, and so we took many of those types, or varieties, that we
- recommend that our farmers grow, and we planted them out in South Africa where they get natural
- infection with wheat stem rust quite frequently. Then, through these tests, unfortunately,
- what Willem Boshoff was able to show, was that all of the wheat varieties that he planted out
- in the field got heavily infected by wheat stem rust. So this tells us that if wheat stem rust
- did become re-established in the UK, then our wheat varieties are very vulnerable to infection.
- Looking back at what our predecessors did to try to prevent wheat stem rust
- and outbreaks back in 1955, where we had our last epidemic here in the UK, it wasn't just inbuilt
- resilience within the plants that they relied upon. They also used another strategy, and this
- was to select for wheat varieties that matured a little bit earlier. To explain this a bit more,
- here in the UK we mostly plant a type of wheat that's called winter wheat, and so this wheat
- is planted in around September/October time, and then over the season it gradually starts to grow,
- and it remains green out there in the field until the end of June. At the end of June,
- it starts to dry out. It gets its beautiful golden colour that we see out there in the wheat field,
- and for our stem rust fungus, it only really likes the tasty green tissue. It only wants to eat these
- plants when they're nice and green, and so these plants are only vulnerable during their green
- stage. Once they start drying out, it's unlikely the fungus will really be able to take hold.
- Also, this stem rust fungus is a bit finicky. It also only likes the summer months. It is what we
- would call a warm-temperature disease, and so by planting earlier-maturing wheat varieties,
- such as the ones shown here, then this meant that the plants were only green out there in
- the field for really around a week or two until they started becoming golden. So
- they were really just at the edge of the stem rust danger zone, where this wheat stem rust
- disease could really take hold, but of course, now with wheat stem rust being a distant memory,
- our wheat plants are now starting to mature a bit later, and we're selecting for ones that mature
- that little bit later. So, for instance, now, this is a much more typical picture of our wheat plants
- that we grow here in the UK, and they're maturing just a few weeks later, which is placing them
- green into that wheat stem rust danger zone. Another factor that's also undermining the
- protection, once afforded to early-maturing wheat varieties, is also due to changes in agricultural
- practices in light of climate instability created by climate change. So, to explain
- this a little bit further, this is a field that is very reminiscent of fields that farmers were faced
- with at the end of 2019. At the end of 2019, that autumn was particularly wet. It was one of the
- wettest autumns on record, and so when a farmer is faced with this picture, and they're thinking,
- well, I need to plant my winter wheat crop in September/October, well, they of course can't
- get out into their fields. They can't even get the tractors out there, let alone thinking about
- the fact that they would have to plant them in soggy soil. I mean, these seeds are not going to
- be terribly happy. So when a farmer is faced with this kind of dilemma, what do they do?
- Well, another option they have to hand is that they can actually change what they're
- planting. Instead of planting the winter wheat that they would have to plant in these kinds of
- wet conditions, they can wait until this deluge of rain has passed, and instead they can plant
- a different type of wheat that's planted in the springtime, and we call that spring wheat. That's
- exactly what farmers did that year, and so if we look at data that's taken here from Ireland,
- which also experienced very similar conditions, you can see that the farmers planted over
- 40 per cent less winter wheat, and over 200 per cent more spring wheat in that year,
- but this comes with a potential issue, and that's that these spring wheat plants tend
- to mature a bit later. So we plant them after the last frost, and then, of course,
- they take longer to develop, so that then pushes them green into the wheat stem rust danger zone.
- So as we go to the future, of course, it's likely that we're going to see more problems
- with climate instability, and these kinds of wet autumns are going to become more common.
- We have to then keep in mind that any increase in spring planting could also then have a knock-on
- effect on increasing outbreaks of diseases such as wheat stem rust. So are we actually
- creating a perfect storm for wheat stem rust to resurge here in the UK? Well, as we look forward,
- we know that many of the measures that were in place back in the 1950s and that have prevented
- wheat stem rust epidemics since that period, are slowly getting eroded. We know that barberry has
- increased in prevalence just naturally because we haven't had a problem with this disease,
- but of course, that then can act as a source of spores and seed outbreaks of this disease.
- We know that within our wheat varieties, they're very vulnerable to infection, and we're also now
- eroding that early maturity that used to protect them from wheat stem rust outbreaks, but luckily,
- we do have our modern fungicides, and they're currently very effective at
- providing a really good level of control against wheat stem rust, but of course,
- relying so heavily on chemicals and chemical application is really not a sustainable strategy.
- So it's clear that wrestling wheat stem rust back into check is going to take an entire community,
- and at the centre of this, all of the lessons that we've learned throughout history, to help ensure
- that we don't see the kind of scale of epidemics that were all too frequent here in the past. So
- once a disease such as wheat stem rust starts to encroach on our crops, it's also important
- that we have really good detection mechanisms in place for rapid detection. We know that all
- three of our wheat rust fungi are serial killers. They're notorious for their ability to rapidly
- spread between wheat plants through the production of vast quantities of these spore-like structures,
- which they use then to spread on the wind and move from one wheat plant to the next to the next,
- and spread the disease throughout an entire field. They can also catch wind currents and travel even
- further, even between continents, and so this is a really effective mechanism for spreading
- disease around. Also, we have to keep in mind that these wheat rust serial killers don't come as a
- uniform form. They also have many different types or biological forms which we call strains. Here,
- we have an example of a strain that's blown into this area, that's represented by these
- yellow-type spores here, and then we have two wheat varieties, wheat variety A and
- wheat variety B. You can see that wheat variety A is very diseased. It's very much infected by
- this particular strain. Whereas wheat variety B stays resistant. It has some resilience against
- this particular strain of this serial killer. Yet, now, imagine a situation where a new strain
- moves into this region represented by these orange spores, and now this new strain has the ability to
- infect both wheat variety A and wheat variety B. So you can see that it's not just important
- that we have a mechanism in place to detect which fungus we have out there in the field,
- but we also need a mechanism that works at a resolution that allows us to determine the
- precise strain that's out there, because that's what the farmers need to know. They need to know
- exactly which wheat varieties are under threat. So to illustrate the sheer devastation that can
- be caused by a new strain moving into a country, we can take an example from Ethiopia, which is a
- country where my team also work. If we go back to 2010, Ethiopia in East Africa suffered the worst
- wheat yellow rust outbreak in recent history. This outbreak was due to a new strain moving into the
- country, and it then affected over 600 hectares of crop. This is over a third of the country's wheat
- production area. It's thought that losses totalled over US$250 million, or over 15 per cent of total
- national production, and so you can see that this was a catastrophic kind of level epidemic here.
- It also brought to the forefront the importance of disease prevention, and also really good disease
- detection, and through some subsequent work, they then started to build a network, working with many
- international partners, and created a wheat rust early-warning system to protect them from this
- kind of scale of epidemics in the future. It's within that framework that my lab were trying to
- see how we can integrate strain level diagnostics into this system. So how do we rapidly identify
- new strains? Well, here, I'd like to firstly introduce you to a colleague of mine, Dave Hodson,
- who works at CIMMYT, the International Maize and Wheat Improvement Centre, and is very much a
- partner in the project I'm going to describe, but I'd also like to introduce you to somebody else,
- a fictional British detective known as Miss Marple, who is the namesake for
- the methodology that I'm going to describe. So the method that Dave and my team have been
- developing is called MARPLE Diagnostics. It stands for Mobile And Real-time PLant disEase
- diagnostics, and it's a method for diagnosing individual strains of our wheat rust serial
- killers out there in the field, and we can carry out this method pretty much anywhere,
- as you can see, working in the back of a car. It also uses the latest portable handheld sequencing
- device shown here, a MinION sequencer that's the size of your mobile phone. It's truly a
- gam-changing strategy that we've managed to develop, that has wide-reaching implications
- for how wheat rusts are diagnosed and will be tracked into the future. So, just to describe how
- this method works in a bit more detail, firstly, we go out, we find an infected plant in the field,
- and then we take a piece of that plant and we then work on that piece of plant. We do some mobile
- sequencing with that handheld portable sequencing device, and this allows us to look at the genetic
- code of our fungus, the building blocks of this fungus that give it its form and function.
- That genetic code is very slightly different between individual strains of the fungus. So
- we can decipher those differences through some magical data analysis. and that allows us to then
- know exactly which strain we have of the fungus in that sample. What's really neat about this method
- is that you can go from getting the sample in the field to knowing which strain you have in just two
- days. and if we compare that to previous methods, previous methods took many, many months. Now,
- we can do all of this in just two days, and get that data in near-real time and integrate it into
- the wheat rust early-warning system in Ethiopia. Also, through the creation of this system,
- we made sure that we also created a mobile lab system, where all of the components needed to
- conduct MARPLE diagnostics are contained within a single hard case. You don't need access to a kind
- of sophisticated laboratory. You really can do this anywhere, and so this creates a truly
- mobile and rapid response laboratory. The fact that you can carry out MARPLE
- diagnostics pretty much anywhere, also means that the samples don't need to be sent overseas. They
- remain with the people in-country, and the ownership of the data analysis also remains
- with those people on location. MARPLE diagnostics is a pioneering step in wheat rust management,
- and we're really excited right now because it's currently being integrated into lots of different
- surveillance systems in many locations around the globe. So now, moving on to the final pillar of
- disease management, which is looking at how we respond to diseases such as the wheat rusts,
- once they've started to become established. Well, just like with other plant-health threats,
- we rely on an integrated approach to disease management, and we also start with, of course,
- the agronomic practices, such as plant hygiene, making sure we don't take an infected plant and
- move it to another location, so having really good practices around plant hygiene. Then, of course
- also making sure that we do things like remove barberry, which can be a source of infection.
- Then, next, we also have, of course, our modern fungicides which are very effective in controlling
- many diseases, but as I mentioned earlier, on their own they're not a sustainable strategy,
- and this is because they contain chemicals that can also, potentially, be quite damaging for
- the environment. So we have to keep in mind that there are a lot of targets around the
- world to try to reduce the use of these modern fungicides, and they're also quite expensive. So,
- for instance, within the European Union, we have the Farm to Fork strategy, which aims
- to reduce pesticide use and risk by 30 per cent by 2030. As I mentioned, modern fungicides are
- not a sustainable strategy on their own, but then, finally, we have resistance breeding,
- and I'd just like to finish on the resistance breeding part for the last part of my lecture.
- So to appreciate the impact of scientific discovery that has had an impact on resistance
- breeding, we can turn back to the beginning of the last century with the phenomenal work
- of Sir Rowland Biffen, who was one of the first scientists to introduce genetic theory within
- resistance breeding. So what Sir Rowland Biffen noticed was that some wheat varieties inherit a
- constitution that makes them capable of withstanding attacks of certain fungi,
- whereas other wheat varieties don't have those constitutions. So he used this genetic theory
- to then add this to his breeding programmes, and then he went on and created many different wheat
- varieties, for instance, creating Little Joss, the first wheat variety that he then released.
- To create Little Joss, he took a wheat variety that had really good resilience against wheat
- yellow rust, and a wheat variety that had high yield. He crossed them together, and then he
- selected offspring that contained both of these characteristics, and there he saw Little Joss.
- So Little Joss was then released in the 1910s, and it was then used by farmers for over 40 years. Of
- course, then Roland went on and he released other wheat varieties, and had a great impact
- on agriculture here in the UK. That's why the farmers were so grateful, and they also hailed
- him as the Wheat Wizard. If we then go on around half a century further forward, we then have the
- pioneering work of Norman Borlaug, who moved to Mexico in the 1940s. He went on to create
- high-yielding and rust-resistant wheat varieties, and also to introduce new agricultural practices
- initially within Mexico, helping Mexico to go from an importer to an exporter of wheat,
- massively improving wheat production in that region. Then he started to advocate for these
- varieties, and also these new practices all around the world, in many different countries,
- and that paved the way to the development of what we call the Green Revolution. The
- introduction of these new practices into so many of these regions around the world actually saved
- millions of people from, ultimately, starvation. So Norman Borlaug was then awarded with the Nobel
- Peace Prize for his contributions to global food security, but also during the period when Norman
- Borlaug was working out there in the Mexican wheat fields, this was also the period where we saw the
- structure of DNA being resolved with, of course, the critical contributions of Rosalind Franklin.
- Then that, of course, went on to allow us to develop DNA markers, which allowed us to look at
- the genetic code of our wheat plants, and to track those constitutions that Sir Rowland Biffen had
- identified. Now we could track them as we knew they were in the DNA, and we could track them
- in the offspring in a genetic cross. So then, of course, at the beginning of this century,
- we also had the genomics era being born, and then subsequently the wheat genome being released. This
- gives us access to the entire genetic code of the wheat plant, and so we can see all of the
- form and function coded within that genetic code, and of course, all of the extensive
- resources needed to have access to that code. Then, just last year, we also saw precision
- genome editing coming to the forefront in the UK for wheat, when we had the first wheat
- trials approved, and precision genome editing has phenomenal potential in the context of
- rust resistance breeding. It would allow us, for instance, to take the constitutions that
- Rowland Biffen identified and to put them in a new wheat variety, move them between wheat varieties,
- stack them in new wheat varieties, adding multiple of these constitutions into a new wheat variety
- in a very precise way. It also allows us to make very small edits within the wheat genome,
- and that can also help to enhance resistance against these wheat rust serial killers. So to
- illustrate the potential of genome editing in that kind of context, firstly, here is a standard
- wheat plant. This particular wheat plant is very susceptible to our serial killer, our wheat rust.
- At the bottom here we have, for instance, infection with wheat yellow rust on this
- particular leaf, and when the fungus infects this plant, what it's doing is it's trying to get all
- of its nutrients that the fungus needs from that plant. It can't live without the plant. The plant
- provides everything that it needs to survive and to prosper, but also at the same time, the plant
- doesn't like being attacked, and so the fungus needs to also turn off all the mechanisms that
- the plant would use to fight it back. So you can see that, if we were to identify those elements
- that the fungus really needs from this plant, and we were able to delete those elements, well, that
- then could make a plant completely resistant to infection, because those elements that the fungus
- absolutely needs to survive wouldn't be present in that plant. So at the bottom here, we have a proof
- of concept where we've edited just one gene of the more than 100,000 genes in the wheat genome,
- and you can see that it's gone in this proof of concept from susceptible to being resistant.
- So I think this really nicely illustrates the huge potential that genome editing has in improving
- resistance in our wheat crops to these deadly serial killers. So as we look to the future,
- I think we've never been closer to realising our goal of defeating these serial killers.
- We have all those lessons of the past that we can use to create really good preventative measures,
- for instance, as you saw in the case of wheat stem rust. We also have these phenomenal technological
- advances in disease diagnostics that could potentially help us to now get one step
- ahead of these serial killers, and finally, the new emerging scientific advances that
- are fast-tracking these resistance breeding, but to achieve this goal it's going to take
- a diversification in scientific thinking. To take full advantage of all of these scientific
- discoveries, it's going to mean that we're going to have to diversify our thinking,
- and this can only be achieved by continuing to promote diversification
- in the leadership among our beloved wheat field. This is precisely what the Rosalind Franklin Award
- will allow us to achieve through the creation of the Rosalind Franklin Women in Wheat Champions
- programme, which is a career-development programme that has many, many components,
- but it also contains right through from one-to-one mentoring to leadership training,
- to ensure that our fantastically talented early-career female researchers are supported
- at that transition period to independence. Whilst, also, this programme will help us to accelerate
- ourselves along our journey to achieving gender parity in wheat research. I think it's only once
- we truly embrace both these new technological advances and a diversity in scientific thinking,
- that as scientists we're going to finally succeed in outsmarting these serial killers
- and make our wheat-production system more resilient for future generations to come.
- So, then, I'd just like to finish by, of course, acknowledging everybody that's been involved in
- the work that I briefly touched on today, right through from our supernatural plant
- pathologists through to our modern-day plant pathologists that work in my team,
- and all of our collaborators around the world, and of course, all of the people that have been
- helping with our wheat career-development programme and the fantastic mentees that we
- have in that programme, our funders, and thank you very much for your attention.
- Thank you for that amazing talk and that engaging way you did it there. It was wonderful. So now
- we're going on to the question-and-answer session of the of this afternoon's programme.
- Let's come over here. We have two roaming mics, which we will go around and take questions
- from the floor. Also to remind those who are here online, that if you go to Slido.com and
- enter the code R2211 - Rosalind, R for Rosalind, 2211, 22nd November, you can send some talks in.
- So thank you. Actually, we already have a couple of questions from the online audience, so if we
- start with those while people in the audience are thinking. From Kate, is there one thing you would
- like to see the crop farmers take on? What is the one thing you think crop farmers could do?
- I think that's a really tough question.
- Well, it's the Royal Society. You'd expect tough questions.
- So I think there's plenty that the farmers can do. I think one of the things that we need to do is
- have really good conversation, and I think also, when we've been talking about wheat stem rust,
- we learned so much in the past that I think maybe has got a bit forgotten,
- because it's a disease that kind of disappeared for a while. So I think it's really important that
- we actually have good engagement and discussion around these things, and what we can learn from
- these lessons of history and actually apply today that could help to protect our crops.
- Is there a good relationship between, say,
- wheat farmers in East Anglia and the scientists out there?
- Yes, I think we do have good discussion, but I think we can always improve this,
- and I think that's definitely something that I would love to see improved even further, yes.
- Yes, the take up of this.
- Yes.
- Jess wondered - I guess I think you spoke to this - is there a way to
- vaccinate wheat against wheat germ, I mean, when we think about you do
- the analysis analogous to humans get disease and plants do too?
- Yes. So I think what we do with wheat plants is we either treat them with chemicals to try to dampen
- down disease or prevent disease from occurring, and we can also then introduce what we call
- resistance into these plants, so we can give them some resilience against infection. That's kind of
- what we have in our hands that we can use to try to protect them against the wheat rusts.
- So we mentioned this earlier, but the resistance,
- or genetic engineering of plants, it seems an obvious thing. You were mentioning it there.
- Yes. So I think it's really important that we think about how we can also integrate some of
- these new technologies in that sphere, because some of these new technologies are super-exciting,
- and they could massively accelerate our ability to kind of speed up the response process,
- because you can see that new strains can appear so quickly, and with these new technologies we have
- the chance now to really accelerate the process of getting these new resistances into crops.
- So what do you plant scientists need to do to influence policy
- and public response to this, because you presented us today with a lecture that says,
- 'This is dangerous and this is really important'?
- I think it's about those conversations and making sure that we have really good open
- conversations about these topics, and talking with lots of different people,
- lots of different stakeholders, and making sure that those things are always discussed openly.
- Are there any questions from the audience? There's one here, please.
- Have you got a microphone?
- Excuse us if we have microphones, because even if you have a loud voice,
- our online audience won't hear otherwise.
- Is there any research directing against the rust, and looking to see - maybe there's just
- too many species, I don't know. It seems to be there's no mention of going down that path.
- So there's a lot of research looking at how they infect, and trying to understand those
- processes better, because that could also help to develop more targeted, for instance,
- fungicides. So you could identify better targets for fungicides that were more specific if you
- were to have a better understanding of how they develop. So I think there's a lot of
- research on that area, kind of developmental biology and so on for fungal organisms, yes.
- There was there was a lady back in white. Thank you.
- Hello, Diane. Thank you so much for your talk. I was just wondering what caused the outburst
- of stem rust 60 years ago. What happened in UK that it came back here? The other one is,
- the secondary host, it's just for stem rust or it's for all three of them?
- So the first part of the question was looking at why stem rust disappeared and then came back,
- and I think we had really good measures in place to try to keep it in check, such as the
- kind of early-maturing wheat varieties. We've had now the modern fungicides being developed,
- so there's a lot to try to keep it in check. The reason that it's starting to, potentially, come
- back is because we're now forgetting about those things, and we're starting to then slip back and
- to, for instance, now grow these later-maturing varieties, and we're also seeing a lot of these
- fungi starting to adapt more. So there's a lot of possibilities for it to re-emerge. I think
- the fact that we saw a big outbreak this year was more due to some of the climate conditions
- that kind of coincided and made a really good situation for wheat stem rust to take on,
- and take over here, and to bring in all of the spores that were needed to kind of spread it
- across the whole of the country, as well, due to some of the wind movement earlier in the year.
- So for the barberry as well, the other question about barberry, barberry can also act as an
- alternate host, as we call it, so another host for the wheat yellow rust fungus too, but it
- can't do that here. As I mentioned, these wheat rusts, these serial killers, are quite finicky,
- so the yellow rust doesn't use its other plant here in the UK, it only uses it in what we would
- call the near-Himalaya region, so it can't be found on barberry here or anywhere in Europe,
- but wheat stem rust does use then barberry, and lots of different species of barberry. Although,
- common barberry is the one that we tend to focus on,
- as it's very infected by wheat stem rust. So does that answer all your questions?
- Thank you. I have another one from the floor, and then I'll go back to the online ones.
- Thank you for a really interesting lecture. You talked about the effect of climate change and
- how that was impacting how and when crops were planted, but you also talked about
- this danger zone for the wheat rust. I'm just wondering could climate change also affect when
- that happens. Would it bring it earlier, and that might affect the wider picture as well?
- Yes, I think that's a really important point, that climate change is going to have kind of different
- effects on our wheat crops and how we grow them, and that danger zone could indeed move
- a bit earlier if the temperatures get warmer a bit earlier. Also, with this particular fungus,
- again, they are finicky, so it also likes damp conditions, and this summer we had actually,
- before the drought kicked in, we actually had some really warm times where we had damp in the
- evenings, and that really helped start the stem rust to take off. So if it was just to
- be very dry and warm earlier in the season, then that wouldn't necessarily be suitable
- for wheat stem rust. It would have to have those kinds of damp night times too, but yes,
- climate change is going to have a big impact on the way that we see these diseases popping up.
- Another way we manage things, for instance, do you remember everybody used to burn the fields,
- burn the stubble, and we all now hate burning the stubble and we don't do it anymore, but was that
- a preventative strategy which we've now taken away from farmers that they can't do anymore?
- I think I think the problem is that diseases can live out there on the wheat stubble when
- it's left behind in the field, so it's good to turn over and to try to get rid of the
- stubble within the field, because it can just work as kind of a little source that
- sits out there and then spreads the disease in the next season. So yes.
- Harry says, what do you think is the future of wheat? Will we have more or less as we
- move forward? Thinking about the questions you've been addressing and climate change,
- I hadn't really realised - this is naivety - just how ubiquitous wheat was. I was kind of thinking,
- well, corn and cassava and things were far more important, and rice.
- So I think you can never really predict how we're going to go with different crops. It might be that
- we see other crops being grown more. Actually, I was looking at a particular study where they were
- showing that many of these crops, we might actually enhance some of the productivity,
- but then the diseases might start to get worse too. So it's like trying to balance these things
- at the same time, and the influence of climate change is on both aspects, yes.
- Mike asks a question a bit more about the future, asking you to be a futurologist. Is
- diversifying the wheat strains we go going to be really important as we move forward?
- So I think, for me, when I think about wheat stem rust, for instance,
- this is a disease that even in history you didn't see an epidemic necessarily
- every single year - you saw every few years - so having a strategy that just deals with
- wheat stem rust wouldn't necessarily be the right strategy. So actually having different
- wheat varieties and thinking about having ones that maybe mature in different times,
- and so on, this is a really good strategy to try to keep diseases under control. So maybe
- it is right that maybe trying to diversify a bit more on what we're planting would be a good idea.
- Thank you. There's another question, one at the front here,
- and then there's one at the back there. This is a home-grown question I think from John.
- It is a John Innes question. I confess to being a very proud colleague of Diane's. Diane,
- I'm currently trying to pull together all the big farmers from Norfolk and Suffolk
- next June to come and talk and listen to you and others about the work you're doing.
- I've been fascinated by the reaction I've got from some people, and it reminds me of when I
- was chairing a London hospital during COVID, how difficult it was to get our staff to realise that
- their lives were at risk. I've actually had one of the biggest farmers in East Anglia saying,
- 'I won't come, because I don't have anything to do with genetic editing.' Are you surprised by that?
- I think there's a lot more that also we do, so there's a lot more discussions to be had,
- but yes, I think it's also about having those conversations, isn't it,
- and having those open discussions, and maybe not having that opportunity would be a real shame,
- that we wouldn't be able to discuss what that really means, because it's important
- that we work with people and discuss these things openly and educate people on what actually these
- terminologies mean, and the possibilities and the opportunities that are out there,
- and utilising genetic - like genome editing, for instance.
- You mentioned the outbreak here in 2010 and the outbreak in Ethiopia in your lecture. Can
- you give us an idea of what kind of price changes follow those sorts of outbreaks,
- and then what impact that has on the food supply and global hunger?
- Yes, so it depends where these things occur. I think it's difficult to say exactly a price impact
- when you're talking about like East Africa, but in the UK you do see that wheat prices
- are modulated depending on how much availability there is. Of course, if we have large outbreaks,
- then of course, that can impact wheat prices, like we're seeing currently with, for instance,
- the war in Ukraine. I mean, this is impacting wheat prices, so any large disease outbreak
- will impact those things, and then, of course, the bread that you go out to buy once a week.
- Thank you. There's one there.
- Thank you very much for that talk. I wanted to ask, do you know of any empirical evidence
- to justify the social resistance to GMO, like sources like GMO food and GMO things in our diet?
- So I think these are maybe a slightly different discussion than more with the genome editing,
- which is a very precise technology, than the GMO approaches. So I think
- these are all very different things. Maybe I didn't quite understand the question.
- Just do we actually have any solid evidence to suggest that,
- in particular genome editing, would negatively affect food sources?
- No, no.
- I think it's a bit the question that we were asking before,
- and maybe it's a general question of sciences and how scientists communicate.
- I think it is about communication, and I think we can always do a better job as scientists,
- communicating what we actually mean when we're utilising these new techniques,
- because sometimes - genome editing is quite fancy terminology,
- but actually it's very simple, what we want to do and what we want to achieve,
- and why we're trying to do these things. I think maybe we need to communicate better
- with people how these technologies work and what actually this means in reality.
- I'd like to suggest you go and talk to our current king, because he was one of the leaders
- about that. There was one more question from the room, but there's also one more question here,
- and we've got one minute. So I'm going to ask this, because I think it's quite an interesting
- question from Siobhan. She's saying, how are biotechnology advances supporting the work?
- I think in some ways, I should comment on how advances in engineering and technology
- and other kinds have been important in your work, because I think that's...
- Oh, definitely. I mean, you look at all the sequencing technologies and so on,
- they've been moving ahead at such a fast pace that they're having a huge impact in
- many different aspects of our work, through from having the wheat genome now available,
- and many different wheat genomes available of different varieties,
- right through to the actual physical technology that we're using for doing
- strain level diagnostics in East Africa and in South Asia. These portable handheld sequencing
- devices blow my mind. This is phenomenal advances that we're seeing in technology.
- I think we should never underestimate how
- important that is to drive fundamental science forward.
- Yes.
- I'm really sorry. I apologise to those who I haven't got to your question online,
- and to those in the audience I haven't got to answer the question, but there is one important
- thing that we have to do here tonight, and that is... It is my honour and great pleasure
- to formally congratulate you and give you this Award from a wonderful woman scientist,
- who did a lot for women in science, to another wonderful woman scientist who is doing great
- science, and also supporting other women in your science career. Thank you. Congratulations.
- Thank you.
- I'm sure that that you'll agree with me that this is an example of a scientist doing brilliant work,
- but also who can communicate well, and it's a lesson to all of us that we not just do great
- science, but we also have to communicate it well. So one last congratulation. Thank
- you all for coming, and I'm sure that Diane will be up here for a few minutes
- prepared to answer some of those burning questions. Thank you all for coming tonight.
Imagine a world without wheat… No bread, no cakes, no pasta and no noodles. But as we speak, the world’s wheat supplies are being ravaged by a dangerous epidemic.
Join us for the Royal Society Rosalind Franklin Lecture 2022 given by Professor Diane Saunders.
Professor Saunders will introduce you to the notorious “polio of agriculture”, the wheat rusts, that throughout history have endangered the production of one of our oldest and most precious food crops.
Despite long-standing efforts by a global community to wrestle the wheat rusts into submission, new strains are constantly evolving that can overcome the barriers we create to inhibit infection, and once again leave the world’s wheat crops vulnerable. Professor Saunders will discuss how phenomenal recent scientific advances have created the tools and resources in our arsenal that now have the real potential to finally outsmart these cereal killers and safeguard a sustainable food supply for generations to come.
Professor Diane Saunders is a Group Leader at the John Innes Centre, Norwich, UK. Her research focuses on (re-)emerging plant pathogens that pose a significant threat to agriculture.
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