Exclusive: Developer of Disease-Resistant, Supermarket Banana Explains How it Works

Australian banana researcher James Dale. Image: QUT

The race to save our supermarket banana from disease is on, and a scientist in Australia – aided by a grant from the Gates Foundation – says that he and his team have developed a genetically modified version of the fruit (the term they use is “biofortification”) that successfully resists the blight that has destroyed much of the banana industry in his country, and that threatens the world’s entire banana crop. I interviewed James Dale for my book. Back then, he talked about how difficult banana breeding is. That remains the case – but this development is a major breakthrough, though he estimates that it will be as long as decade before the fruit he’s working with truly proves its worth.

I first wrote about the breakthrough last year. Here’s a more extensive interview with Dale that I conducted in January. In it, he gives details on the project – and where it might be going.

DK: Panama Disease is highly transmittable – I wonder about how you’re able to actually test these resistant plants that you’ve developed, especially in a country that’s already got a huge problem with the disease. Aren’t you and the Australian banana industry concerned that – since you have to expose these plants to PD – you might inadvertently let something escape?

JAMES: Needless to say, there would be concern about doing those challenges even in the glasshouse. So yes, the bio-security people are very, very concerned about this. Our tests are either going to be conducted where the disease already exists – in the Northern Territory – but also in Southeast Asia. Right now, we’re negotiating where to conduct those trials.

DK: So right now, you’ve only tested against Tropical Race 4 in the greenhouse?

JAMES: No, we haven’t tested against Race 4 in the greenhouse – we’ve so far only tested against Race 1 in the greenhouse.

Note: Panama Disease has different variations. Tropical Race 1 is the “original” version that killed the first commercial banana, the Gros Michel. The Cavendish – our banana – replaced that fruit in the 1950s and 1960s because it was immune to Race 1. Tropical Race 4 appeared in the 1990s, shocking the banana world because it affected the Cavendish, and beginning the race to find a remedy for the blight. The technical name for these disease is “Fusarium Wilt.”

DK: Would resistance to Race 4 necessarily be carried over?

JAMES: We believe so – the hypothesis is that there’s no reason to think that the genes we’re working with in Cavendish won’t provide resistance to Race 4.

DK: Cavendish is already resistant to Race 1 – that’s why it was adopted – so how is that a legitmate test?

JAMES: We have generated transgenic Lady finger expressing the resistance genes. Lady finger is susceptible to both Race 1 and tropical Race 4. We have challenged these transgenic lines in the glasshouse with Race 1 and have identified a number of highly resistant lines. The resistance strategy is not targeted to Race 1 but is targeted to inhibiting a basic infection process of Fusarium. Therefore, we believe there is a reasonable chance that the genes that provide resistance to Race 1 in Lady finger will also provide resistance to Race 4 in Cavendish. But we still need to do the challenges.

DK: What kinds of genes are you using?

JAMES: The one we’re taking into the field comes?

DK: Right. And where are the genes coming from?

JAMES: We’ve accessed a whole lot of genes. The one that we’re taking into the field is a nematode gene. But we’re also pulling out equivalent plant genes. We didn’t have them when we started making these plants, so we were using genes from other organisms including nematode one, which works very well. So, we’re now isolating the equivalent plant genes and putting those into bananas. And that will be tested in the glasshouse first.

DK: So that may be something you’ll have to deal with commercially. Are you otherwise finding enthusiasm on the part of the Australian banana industry with the preliminary results you have? Is there an overall sense that you might be able to get a handle on a problem that’s been so brutal on the industry, or is there a disconnect between what you’re doing and any future commercial benefit?

JAMES: Well, the official policy of the Australia Banana Growers Council is that they support the research and development, that at the present time they do not support commercialization of GM bananas. Which is a very sensible attitude. But that having been said, they are supporting both the field trials, and in fact the field trials are very likely going right into the center of the major banana growing area in Australia and the growers are comfortable with that, which I think is very important.

DK: And how did you – in terms of telling the story of that – did you get them to go along with that. Did you have to approach them and convince them? Was it easy to explain what you were doing? Have they been with you the whole way?

JAMES: The relationship is very good. The banana growers been funding our work in the banana transformation program since the early days, through another group – Horticulture Australia. More recently, the funding is coming from the Australian Research Council and the Bill & Melinda Gates Foundation. The Australian banana growers probably not going to be the first to take up GM technology and probably not the first in bananas but they’ve recognized that it potentially has an important place in the future of the industry. I think they see it as an insurance policy.

DK: Do you think the American banana companies are keeping up with what your Australian industry is doing? There’s not an urgency, it seems – because the problem is actually happening in Australian – but do the big U.S. companies know what the situation is?

JAMES: I would say I would be amazed if they weren’t keeping abreast what’s going on.

DK: To change the subject, tell me a more about what you’re doing, specifically what the involvement of Bill & Melinda Gates has allowed you to do, and how that’s played out over the past couple of years, and where that’s going?

JAMES: The Gates Foundation Project started by focusing primarily on Uganda and the development of East African Highland bananas, which is their cooking banana. Ugandan bananas are a staple food, as they are in a number of countries around Lake Victoria – in Rwanda and Burundi, in Tanzania, in the eastern part of the Congo, and also in the highlands of Kenya. In Uganda consumption is about one kilo per person, per day (note – the equivalent of about fifty standard bananas per week). That’s just incredible.  The problem with those bananas is that they’re relatively low in pro-vitamin A as well as in iron and as a result, the banana-based diet leads to deficiencies in those nutrients, which causes major health problems. Probably the best way to deliver those nutrients is through the staple food. So our project has been to develop East African Highland bananas with high levels of pro-vitamin A and iron, and we’ve now got to the stage where we’ve got the first generation with plants made, and now we’ve got to take them into the field, which we’re going to be doing over the next few weeks. So we should have a good indication by the end of next year about the levels of the nutrients we’ve been able to obtain in that first generation of plants.

DK: And are these field trials also going on in Australia?

JAMES: Yes. But we’re also in the process of applying to the National Research Organization of Uganda for permission to conduct trials there. I should add that the bananas we’re working with here in Australia are Cavendish – when we transfer the technology to Uganda, it would move over to the African bananas.

DK: In talking to some of some of the other folks working on bananas and in terms of food security and nutrition and things like that, one of the things I have often heard complaints about is that the food security world doesn’t really see bananas the way they see wheat and rice and corn, and that bananas have been the neglected stepchild. How did you actually getting an organization like the Gates Foundation to recognize the importance of bananas and actually fund some useful research?

JAMES: Right – bananas have traditionalyl been neglected. Our program comes through what’s called the “Grand Challenges in Global Health Program.” The Gates Foundation came up with fourteen areas in global health that needed attention, one of which was around developing staple foods with complete sets of nutrients. Out of that core they funded four projects – with cassava, sorghum, the Golden Rice project (which was already underway), and our banana project. (Note: the Golden Rice project is one of the best-known biofortification initiatives. It began in 200X, and seeks to improve the Vitamin A content of the world’s primary staple grain.) Rice is the biggest project, and it is the furthest along, so it was a good one to include – but the other crops are essentially orphan crops. There just haven’t been enough people thinking about them from a food perspective, and I think we made a strong case to the Gates Foundation that there are something like 100 million people that absolutely depend on bananas, and that there are many, many times more – particularly in the tropics – where bananas are a major part of their diet, where they may not be a staple, but they play an almost indispensable role.

DK: And that was understood?

JAMES: Once you explain it that way, and put it in the context of the challenge that the Foundation was making, yes. People do start to switch on.

DK: How much is the Gates Foundation actually contributing to your effort?

JAMES: The first four years of the project, which finishes in June, 2009, we received just over US$3 million dollars. We’re now preparing an application to go into Phase Two which is for another three years.

DK: Back to the science – we’ve been talking separately about your project with Fusarium Wilt (Panama Disease) and your project with bio-fortification, but really, you have to take both things together. You need to build bananas that resist disease, as well as nourish people. How do you conduct research? Is your lab broken into two units, or do you work in a more holistic way?

JAMES: We’re working on them all together, you’re absolutely right, Dan. In fact, one of the projects we’re really pushing now is that the East African Highland banana, which is the big, starchy banana that they grow and harvest green and then steam for four or five hours, is certainly the preferred banana by the vast majority of the population, but the little kids, the kids that are under five, they like the little sweet bananas. And the little sweet banana that is the favorite right around that region is a banana called Sukali Ndizi. The little kids eat it, so we’re looking to bio-fortify that, but its biggest problem is that it’s susceptible to “Race One” [sp] and it’s starting to disappear.  So we’re obviously working towards incorporating the Fusarium resistance into that banana, together with the bio-fortification.

DK: So you’re working on that particular banana in your lab?

JAMES: No we’re not. We don’t have those bananas in Australia so we’re using Lady Finger as a model Sukari Ndizi.

DK: I see. Do you have the ability to have any kind of commercial benefit from developing a stronger Cavendish for your work in the public domain?

JAMES: The majority of our stuff is in the public domain. As a university, obviously, universities are always interested to commercialize outcomes. However, one of the requirements, and I go along with it, of the Gates Foundation, is that anything we develop as part of the program has to be available to subsistence farmers without the necessity to pay license fees, royalties, etc., so that’s a very important part of the global access strategy.

DK: Right. Still, developing the super Cavendish is something that would certainly make the folks at Chiquita very happy if they were able to actually convince consumers to buy it further down the road.

JAMES: Which I believe, ultimately, will come. My belief is that we will see the breakdown of resistance to GM very similar to the way we saw the breakdown of the Berlin Wall.

DK: Right. I say in my book that I think that the GM Cavendish is the answer also.

JAMES: That’s right, I remember that. I heard an interview you did, it was probably back in April, and I can’t remember who you were doing the interview with, but it was about your book.

DK: Yeah, I mean, it’s interesting. The world is against “Frankenfoods”, I guess, but it’s a silly term and it’s a silly prejudice, I think. It is, it is a prejudice, let’s put it that way.

JAMES: That’s right.

DK: I know a lot of field testing doesn’t always play out over the years for these kinds of things, I mean, at what point will you feel confident that you’ve actually solved these problems that you’re looking to solve?

JAMES: That’s a hard one. The bio-fortification, I think, is much more straightforward. I think we will know very quickly whether the technology that we’ve been using is effective. I think that’s not going to be a huge issue. If it’s effective, then we’ve got the strategies of how we take that through, actually, right to the farmer release. So we’re not talking about commercialization, we’re talking about releasing it to farmers. And most of the genes that we’re using, they’re plant genes. I think we’re going to see quite solid support and very little negativity. As long as we haven’t altered something else in the banana, and I don’t think we have from all of our experimentation to date, then we move to disease resistance which is, I think, quite different because we need to be confident that we’re actually creating resistance to all the variants of Fusarium. We don’t want to have done something, we don’t want to generate very narrow resistance. We need to generate quite broad resistance to Fusarium so that will take a significant period of time to become confident that what we’ve generated is truly a robust resistance.

DK: Right, right. So you’re going to have to go to places where you’ve got these different varieties of Fusarium, I assume, and plant several generations in order to really work this through.

JAMES: That’s right. We’re going to have to have them, for instance, there are fields in southeast Asia that have been devastated, where Cavendish has been devastated with Tropical “Race Four.”

DK: What is your annual budget? How much is the Gates Foundation actually actually funding you for?

JAMES: The first four years of the project, which finishes in June, 2009, so it’s just in the process of preparing an application to go into phase 2, the budget was just over 3 million dollars.

DK: Okay. We’re talking, really, separately about your project with Fusarium wilt and your project with bio-fortification, but really you have to take both things together, in a sense, you have to build resistant bananas as well as ones with the nutrient qualities you’re describing.

JAMES: Absolutely …

DK: So is your lab broken into these two units, or are you all working on these things together in a more holistic way?

JAMES: We’re working on them all together, you’re absolutely right, Dan. In fact, one of the projects we’re really pushing now is that the East African Highland banana, which is the big, starchy banana that they grow and harvest green and then steam for four or five hours, is certainly the preferred banana by the vast majority of the population, but the little kids, the kids that are under five, they like the little sweet bananas. And the little sweet banana that is the favorite right around that region is a banana called “Sukali Ndizi”. The little kids eat it, so we’re looking to bio-fortify that, but its biggest problem is that it’s susceptible to Race One, and it’s starting to disappear.So we’re obviously working towards incorporating the Fusarium resistance into that banana, together with the bio-fortification.

DK: So you’re working on that particular banana in your lab?

JAMES: No we’re not. We don’t have those bananas in Australia so we’re using Lady Finger as a model for Sukali Ndizi. (Note: Lady Finger is a small, sweet banana – in the U.S., it is sold in limited markets under the Chiquita Minis brand name.) Lady finger is a good model for Sukali Ndizi because they are both triploid AAB bananas (two genomes from Musa acuminate plus one genome from Musa balbisiana) and are both susceptible to Fusarium Race 1. Also, the resistance genes we are using are designed to interfere with a basic infection process of Fusarium and should have the same effect irrespective of the banana cultivar.

DK: Back to Cavendish – our endangered supermarket banana: finding a replacement could save the banana industry from disaster – and it could also be a gold mine. Do you have the ability to derive any kind of commercial benefit from developing a stronger Cavendish, or is your work in the public domain?

JAMES: The majority of is in the public domain. But we are a university, and obviously universities are always interested in commercializing outcomes. However, one of the requirements, and I go along with it, of the Gates Foundation is that anything we develop as part of the program has to be available to subsistence farmers without the necessity to pay license fees, royalties, etc. So that’s a very important part of the global access strategy.

DK: That makes sense. Still, developing a sort of “Super Cavendish” is something that would certainly make the folks at Chiquita and its rivals very happy if they were able to actually convince consumers to buy it further down the road.

JAMES: Which I believe, ultimately, will come. My belief is that we will see the breakdown of resistance to GM very similar to the way we saw the breakdown of the Berlin Wall.

DK: Returning to the technical aspects of your work – I know that a lot of the qualities you add to new banana breeds doesn’t always play out after several generations in the field. At what point will you feel confident that you’ve actually solved these problems that you’re looking to solve?

JAMES: That’s a hard one. The bio-fortification, I think, is much more straightforward. I think we will know very quickly whether the technology that we’ve been using is effective. I think that’s not going to be a huge issue. If it’s effective, then we’ve got the strategies of how we take that through, actually, right to releasing the breeds to farmers – especially because we’re not talking about commercialization, we’re talking about releasing it to farmers.   When we move to disease resistance, that’s quite different. We need to be confident that we’re actually creating resistance to all the variants of Fusarium. We don’t want to have done something that generates only very narrow resistance. What we create needs to be broad, and it will take a significant period of time for us to become confident that what we’ve generated is truly a robust resistance.

DK: Any idea how long that time period would be?

JAMES: Our first banana disease resistance field trial is just beginning and it is with the first version of the genes. The strategy will have to be refined and tested again and then in multiple environments. And finally, these plants would need to be deregulated. It is very hard to put an accurate timeframe on this but with current levels of funding it would be at least 10 years before release of Fusarium wilt resistant bananas to farmers.

DK: Thanks so much. I know that the entire banana world is hoping that you’ll have continued success.

Tags: Banana Australia, Banana New, James Dale