Interview with Ray Dixon

In December 2016, our UK lead Ray Dixon, was interviewed by a member of the JIC external relations team. Here, we find out all about Ray’s involvement with the UBNFC.

Lawrence
Hello Ray, I’ve just been reading about all the different partners in this dual-country collaboration. How did so many distinguished parties come together?

Ray Dixon
I’ve been travelling to Brazil for quite a number of years as a visiting professor at the Federal University of Paraná in Curitiba and we have hosted several Brazilian students at JIC as a partner in sandwich PhD programmes. Also, as chairman of an international committee I have had a role in overviewing biological nitrogen fixation research in Brazil, and consequently the opportunity to make contact with many Brazilian scientists working in this field.   So it was relatively easy to approach teams working on this area in both Brazil and the UK and ask them to join us in order to establish this Virtual Joint Centre.

Lawrence
So you’ve been travelling to Brazil for a long time, and thinking about how to connect and create partnerships between the UK and Brazil, and international collaborations is something the John Innes Centre is known the world over for, but at what point was the UBNFC seed planted? At what point did you think ‘Okay, we need to get this network happening on nitrogen fixation’?

Ray
We have had excellent interactions between UK and Brazilian scientists in the past, but these had been funded mainly on an ad hoc one-to-one basis, which did not give us the opportunity to establish larger networks.   The creation of the Newton Fund has changed all this and given us the framework to build better links between the UK and Brazil in which broader networks of scientists can collaborate together in an integrated research partnership.

Lawrence
How did it begin? Did you start conversations in the UK first and then ask the Brazilian counterparts to join, or did you reach out to both countries at the same time?

Ray
We had a BBSRC town meeting last year in London in March 2015, which brought together UK scientists who were interested in establishing Newton funded Virtual Joint Centres with Brazil, India and China. We met with Brazilian representatives at that meeting, which is where the conversations started in earnest.

Lawrence
Was it then a case of visiting all the different partners in Brazil, pitching the collaboration to them?

Ray
I approached my colleague Emanuel De Souza, who is a professor in the Department of Biochemistry and Molecular Biology at the Federal University of Paraná, and through him we communicated with the other groups in Brazil who agreed to join us.

Lawrence
And now we’re here at the birth of this network, where all parties are sharing a common goal. If you had to distill that, what would be the main aim of the UBNFC?

Ray
We wish to understand and exploit interactions that occur between soil microbes and plants to improve agricultural productivity and reduce the use of chemical nitrogen fertilizers. What we’re doing is characterising soil bacteria, which interact with various crops in Brazil, and we want to improve those bacteria so that they’re more efficient at promoting the growth of these crops by using their ability to perform biological nitrogen fixation. There is a tremendous diversity of plant microbe interaction that we can study in Brazil. We’re not only working on crops that provide food for humans, we’re also researching bio-energy crops that can be used for providing energy or feeding animals. Perhaps I should explain what biological nitrogen fixation is first?

Lawrence
That would be great.

Ray
Essentially, the green revolution (using new methods of cultivation and having plants that grow efficiently via plant breeding) has helped feed the world over the last 50 years. But in order to sustain that level of food production, you have to provide synthetic chemical fertiliser. The main ingredient in fertiliser is what we called ‘fixed nitrogen’. So we have used chemically derived nitrogen to feed the world. The problem with this is it causes a huge amount of pollution, particularly in intensive agriculture because of run off which pollutes aquatic areas, and because of reactive forms of nitrogen leading to atmospheric pollution. Now there is another way of making fixed nitrogen and that’s called biological nitrogen fixation. It involves taking nitrogen gas from the air and making ammonia in bacteria. We’ve known for many years that this happens in legumes and that legumes do not need nitrogen fertiliser as long as the appropriate microbes are present in the soil. These bacteria can form a symbiosis with legumes, effectively producing little factories for nitrogen fixation on the roots of the plant. But we also know there are free-living bacteria in the soil which fix nitrogen, but while they associate with all sorts of crops they are not very efficient at giving their nitrogen to the plants.

Lawrence
They keep it for themselves?

Ray
Bacteria in the soil are not altruistic with respect to the nitrogen they fix.  So what we’re doing is engineering these bacteria so that they start to release ammonia when they are close to the plant, effectively delivering their fixed nitrogen to the plant. We also have to do some other engineering to allow the plant to signal to the bacteria and perhaps provide the bacteria with a source of energy to help them fix nitrogen. So what we’re doing is creating artificial marriages between bacteria and plants.

Lawrence
You’re teaching the plant to ask for the nitrogen and encouraging the bacterium to be willing to share it?

Ray
Yes, it’s kind of like that. Or in other words it’s really getting the plant to sense there’s a microbe in the soil which probably fixes nitrogen and signal to it to associate more closely and share nutrients, in order to get ammonia from the bacteria and not from chemical fertiliser.

Lawrence
So is it almost like teaching the crop to make mutually beneficial friendships in order to provide for itself, so that we don’t have to provide for it?

Ray
But we still have to treat the crop with the bacteria in order to get the growth benefit. We are giving something to the crop to help it grow without fertilisers. We want to encourage an association, and we want the plant to control the way the genes are expressed in the bacteria so crops get their optimal level of nitrogen. One concern is that to a certain extent some of these mechanisms can disable the growth of the bacteria, so there’s a danger of making these bacteria not as competitive as the native ones. So what we want to ensure is that the plants say to the bacteria ‘Only turn on this system when you’re close to me’.

Lawrence
So the bacterium doesn’t give its ammonia away unnecessarily.

Ray
Because otherwise the bacteria would be giving freebies away all the time, and all their competitors in the soil would just say ‘ooh, thank you very much’. The engineered organisms won’t survive very long that way. There will be social cheaters in the population taking it for free instead of creating their own.

Lawrence
It’s like when nice guys are taken advantage of. They need to learn to choose whom to be nice to.

Ray
Indeed.

Lawrence
Which crops for human food would benefit?

Ray
Mainly, wheat, rice and maize, which are important in Brazil.

Lawrence
And do you have any projections? If this can be achieved, how it would change Brazilian economics? What impact would it have?

Ray
Well, farmers are already starting to use what we call inoculants. These are the bacteria that they spray onto their crops instead of using chemical fertiliser. But, we know that these are not very efficient. What we hope to achieve is to deliver the total nitrogen requirement of the crops, so we don’t have to use any chemical fertiliser at all. Economically this is very important because inoculants are extremely cheap to produce, so the actual cost to farmers is minimal compared to buying fertiliser nitrogen. So our research can benefit farmers, help to reduce the greenhouse effect and increase the economic development of Brazil.

Lawrence
So, how is the UBNFC network going to work, practically speaking, towards achieving this goal? You have the experts in Brazil; they are on the ground there. You have advanced scientific research here in the UK. How is this journey being shared between the two countries?

Ray
We all have our specific areas of expertise, which feeds into the whole. If we talk about the UK side, my lab at the John Innes Centre will be doing most of the engineering to ensure bacteria deliver the ammonia. Then a group in Aberystwyth will be working on isolating different bacteria, which can associate with bio-energy crops. The Oxford group are experts in creating genetic switches which only turn on the genes required at a particular time and space when close to the plant. So we all have our own areas of expertise here and each group in Brazil brings their own areas of complementary expertise to the collective too. We will have an annual meeting and individuals will meet face-to-face several times a year. We can communicate by exchanges, with UK scientists going over to Brazil and Brazilian scientists coming to the UK. We will hold workshops in which we will train Brazilian scientists in specific techniques. And, of course there’s Skype!

Lawrence
Great, so I guess we can have another chat in a years’ time and there’ll be lots of interesting developments to talk about.

Ray
I sincerely hope there will be. We’re all looking forward to what we can produce together.

Lawrence
Our 15 minutes are up Ray, thanks so much for talking to me.

Ray
You’re very welcome.