#238      23 min 41 sec
Rice futures: Biofortifying food crops for better nutrition

Plant molecular biologist Dr Alex Johnson explains how genetic engineering of rice grain could help to stave off malnutrition in the developing world. Presented by Dr Shane Huntington.

"In developing countries, one of the main factors that contributes to micronutrient malnutrition is the very heavy reliance on cereals, for instance rice, which is the cereal crop that I work on the most.  This can be up to 80 per cent of the total caloric intake for people in developing countries.  Most of their daily energy is coming from cereals, and cereals are generally low in all three of the micronutrients that I just talked about.  So iron, zinc and vitamin A, they have very low levels, if any at all." -- Dr Alex Johnson




Dr Alex Johnson
Dr Alex Johnson

Dr Alex Johnson is a plant molecular biologist working on increasing the nutritional value of cereal crops. Food staples with low concentrations of micronutrients cause chronic nutritional problems for people in many areas of the world. Rice, one of the most widely consumed cereal grains in developing countries, provides up to 80% of total caloric intake in areas such as South-East Asia yet the polished grain – commonly referred to as “white rice” – contains very low concentrations of essential micronutrients such as iron (Fe). As a result, over 2 billion people, or 30% of the world’s population, suffer from Fe deficiency with symptoms ranging from poor mental development in children, depressed immune function to anaemia.

Alex’s lab is using biotechnology to generate new cereal varieties that load increased concentrations of Fe into the grain, an approach known as “biofortification.”

Alex also has interests in stress physiology and leads up the Melbourne node of the Australian Centre for Plant Functional Genomics.

Selected publications

Credits

Host: Dr Shane Huntington
Producers: Eric van Bemmel, Kelvin Param
Associate Producer: Dr Dyani Lewis
Audio Engineer: Gavin Nebauer
Voiceover: Nerissa Hannink
Series Creators: Kelvin Param & Eric van Bemmel

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VOICEOVER 
Welcome to Up Close, the research talk show from the University of Melbourne, Australia.  

SHANE HUNTINGTON 
I'm Shane Huntington.  Thanks for joining us.   In the developed world it’s quite common for people to take a range of dietary supplements. And even if they do, many still don’t receive all the essential nutrients their bodies need.  Translate this problem to the developing world and instead of mild deficiencies we observe extremes of malnutrition.  What if we could modify our food crops to pack a bigger nutritional punch to meet all of our daily dietary requirements?  Would societies be willing to accept genetically modified rice or wheat if it meant the difference between a healthy diet and malnutrition? And what role will these food fortification technologies play in meeting the needs of an ever increasing global population?  To discuss these issues we are joined today on Up Close by plant molecular biologist, Dr Alex Johnson, from the School of Botany at the University of Melbourne.  Welcome to Up Close, Alex.  

ALEX JOHNSON
Thank you.

SHANE HUNTINGTON
Alex, the ultimate goal of your work is to address the problem of malnutrition.  Could you start by giving us an idea of the scale of this problem?

ALEX JOHNSON
Sure.  I’m most concerned with iron deficiency.  Iron deficiency is the most common micronutrient deficiency in the world.  It’s believed to affect at least 30 per cent of the world’s population, so more than two billion people, and it has a wide range of symptoms.  Some of them are more visible than others.  Iron deficiency at a young age in children can impair mental development.  As you get older it can depress your immune system, which can have a devastating debilitating effect on mothers in particular, and it increases the risk of maternal and child mortality.

SHANE HUNTINGTON
Is iron deficiency the primary problem of nutrient deficiency in developing nations, or is it other things as well?

ALEX JOHNSON
In developing nations there’s generally three big micronutrient deficiencies that we talk about and aim to correct.  That would be iron deficiency, vitamin A and zinc deficiency.  So those three are the big deficiencies that affect people in developing countries.

SHANE HUNTINGTON
What sort of things do they do to you when you don’t have those in your diet?  We obviously have so many of these different vitamins that we have to be taking in - this is just three of them.  What happens to you if you don’t have those particular vitamins in your diet?  

ALEX JOHNSON
I’ve already mentioned what happens with iron deficiency.  With zinc deficiency you can have stunting, that’s a big problem, particularly in children, and vitamin A’s necessary for vision.  So if you don’t have enough vitamin A you can go blind and there’s also mortality associated with vitamin A deficiency.

SHANE HUNTINGTON
When we look at areas in the developing world, what are the primary causes of this nutrient deficiency in what’s available in terms of food?  Is it war, government, or are there other factors that are causing these things not to be available in the diet?

ALEX JOHNSON
There’s a wide range of factors that affect how much nutrient people get.  In developing countries, one of the main factors that contributes to micronutrient malnutrition is the very heavy reliance on cereals, for instance rice, which is the cereal crop that I work on the most.  This can be up to 80 per cent of the total caloric intake for people in developing countries.  Most of their daily energy is coming from cereals, and cereals are generally low in all three of the micronutrients that I just talked about.  So iron, zinc and vitamin A, they have very low levels, if any at all.

SHANE HUNTINGTON
Now, when we move back to developed countries, food here is far from scarce, we have a luxurious environment in that regard.  We have access to many nutrient supplements, and yet still we find a lot of people have nutritional deficiencies.  What sort of things can be done in these wealthier countries in terms of addressing these deficiencies?

ALEX JOHNSON
Right. In developed countries, not only do we have these supplements, which you’ve mentioned, but we also have a very well-developed food processing industry, and if you have a well-developed food processing industry you can fortify your foods.  So that’s what we often do.  For instance, with breakfast cereals, you’ll see that they often say that they’re a rich source of iron, or rich source of zinc.  That’s not natural, that’s not coming from the plant, it’s coming from the food processing where we’ll add usually water soluble compounds to that product to let you get your daily needs from iron and zinc.  For iron, for instance, there’s a compound called ferrous sulphate that we often add to our breakfast cereals, and to our breads, and that will increase greatly the amount of iron we get into our bodies.

SHANE HUNTINGTON
Alex, when we talk about biofortification and putting these things into our foods, like you mentioned cereals and so forth, how do you physically get these materials in there?  What’s the process of adding to what is just a normal food off the shelf?

ALEX JOHNSON
Biofortification is - yeah, to naturally increase the levels of say iron, zinc and vitamin A.  What we do is we - first we try to breed for that trait, just like any other trait.  So cereals, we’re continuously trying to improve their fertiliser use efficiency, that’s something we breed for.  This is no different.  So if we want to have an iron rich cereal, we would try to breed for that by selecting iron enriched plants and crossing them together.  What we found with the case of iron is that conventional breeding hasn’t worked for us.  We’ve had very small increases in the amount of iron in the grain, but not significant.  That’s why we’ve turned to genetic modification in the case of iron deficiency.

SHANE HUNTINGTON
I’m Shane Huntington, and you’re listening to Up Close.  In this episode we’re talking about how to make crops more nutritious through biofortification with molecular biologist, Dr Alex Johnson.  Alex, you’re using genetic engineering to make rice with greater iron content - could you give us an idea of how this process actually works?  How do you go about genetically modifying a plant?

ALEX JOHNSON
There’s several ways available to genetically modify a plant.  The way that we most commonly use - that plant molecular biologists most commonly use utilises the bacteria that you find in the wilds called Agrobacterium.  Agrobacterium naturally infects plants and produces what we call galls on trees.  You see those large tumour-like protrusions on trees, those are caused by Agrobacterium which has naturally modified that tree to produce a gall that it now feeds on.  We simply use Agrobacterium to transfer any gene into a plant.  So that is the most common way to modify a plant.  

SHANE HUNTINGTON
How controlled is this process?  Do we understand when we add the genes via this bacterial sort of vector that it goes to a certain location?  Is it random?  Do we have control over all of that?

ALEX JOHNSON
We don’t have control over where the gene inserts into the DNA of the plant, but we can figure out where it has inserted once the event has occurred, and then it’s a stable insertion, it will remain there for generation after generation in the same place.

SHANE HUNTINGTON
Given the randomness of that scenario, is every plant that you do this to different?

ALEX JOHNSON
Yes.  We generate for any trait that we’re trying to modify.  We might make 30 or 40 different plants.  We call them events.  Each one is different.  Then we characterise them to find where the gene has inserted.  So if this is a gene that’s raising iron concentrations in the grain, we’ll characterise all 40 of the events and ideally we’ll find an event where our new gene has inserted in a place that has not disrupted a native gene.  

SHANE HUNTINGTON
So you’ve got a single plant at that point where you’ve made the modification that you’re trying to make.  How do you go from that to a crop of thousands or tens of thousands of plants?

ALEX JOHNSON
It’s a long process that can take five or 10 years at least, because what you need to do is regenerate your plant and you need to characterise it. And characterisation can take many years.  You need to grow the plant up.  In our case, we need to look at iron concentrations in the grain, and we’d want to do that on our first plant, and then we’d also like to look at progeny from that plant for many different generations to ensure that our trait is stable.  You then need to go into the field - and field trials are what I’m doing right now, for at least the next five years - and you just want to make sure that your plant performs as well as say a conventional crop in the field.  Then finally you would need to get your crop into a target country. So, one of our target countries in Bangladesh - and you’d want to begin crossing our iron enriched rice to rices they grow there, and that can also take at least five years to bulk up the seed. 

SHANE HUNTINGTON
Certainly a long turnaround time.  When we talk about the gene that you put in, where does this gene come from?  Is it an existing part of the plant that you’re modifying, or is it from a different organism entirely?

ALEX JOHNSON
We are working with an existing rice gene.  So the way that we have created iron enriched rice is we’ve looked at the iron deficiency responses that rice has.  So rice has quite high needs for iron.  All organisms have needs for iron.  When rice wants to take up more iron from the soil it does so by upregulating a series of genes, and one of those genes is called nicotianamine synthase - it’s kind of a long name.  But this particular gene only comes on when the plant wants to take up iron from the soil, and it’s a very effective way of taking up iron.  And what we’ve done is we’ve simply modified the regulation of that gene in our plants.  So rather than have that gene only come on when the plant wants to take up iron, when it’s deficient in iron, our plants have this gene active at all times throughout their development.  This allows them to take up much more iron from the soil and put more iron into the grain.  

SHANE HUNTINGTON
Alex, when we move into the lab and we’re talking about using a particular bacterium to get this gene into the material or into the plant we want to have the gene in, how do you physically go about doing that?  What’s the process?  What’s going on with the bacterium and the gene that it’s taking in with it?

ALEX JOHNSON
If we’re going to use bacteria for gene cloning we need to do a little bit of preparation work with that bacteria.  First of all what we need to do is remove the genes that Agrobacterium typically puts into trees to create those galls.  We call those oncogenic genes.  These are genes that incurred auxins and cytokinins.  They cause cells to divide uncontrollably and they create that gall that we see on trees.  All of those genes are contained in a little piece of DNA called transfer DNA.  So we simply remove those genes - you can just cut them out - and then we can paste in what other gene we would like to move.  In our case we took a rice gene, this nicotianamine synthase gene, we changed its regulation by changing what drives it - that’s called a promoter - we pasted that into the transfer DNA, and then put that back into the Agrobacterium.  So now we have a modified Agrobacterium in the lab and then you can just incubate that with rice tissue.  Now the Agrobacterium, instead of putting the gall inducing genes into rice, it will put a rice gene back into rice, just with altered regulation.  Then there’s about a three month procedure of tissue culture to regenerate a new plant from that.  That’s essentially how you produce a genetically modified rice plant.

SHANE HUNTINGTON
You have a plant that’s capable of taking up all these nutrients.  Is the whole scenario though soil-dependent?  If you have relatively poor soil - and I suspect in many countries in the world this would be the case where they have challenging agricultural scenarios - how do these plants work when the soil is limiting?

ALEX JOHNSON
Iron’s an unusual element because there’s lots of it in the earth’s soils.  It’s the fourth most abundant element in our soil.  The issue with iron is that it’s very insoluble.  Under aerated conditions, conditions that have oxygen - and at normal biological pH it’s very insoluble.  So there’s a lot of it in the soil but plants and other organisms have a difficult time taking it up.  Our plants are simply better at keelating - we call this keelating or solubilising the iron so that they can absorb it from the soil.

SHANE HUNTINGTON
So in comparison to traditional plants, how much additional iron do these genetically modified plants provide?

ALEX JOHNSON
Our genetically modified rice plants have around four times more iron in the grain that people eat, and we’ve gone to great lengths to figure out where the iron accumulates in the grain.  It’s actually in the polished grain, or the white rice that people most commonly consume in developing countries.

SHANE HUNTINGTON
Does this source of iron become their primary source of iron?

ALEX JOHNSON
In a heavy rice based diet it would be their main source of iron, yes.  If you’re on a diet which is 80 per cent rice, that would be your major intake of iron.

SHANE HUNTINGTON
Alex, it seems incredibly fortuitous that the iron’s ended up exactly where you need it in the plant.  Was this just luck or did you guys specifically do something that led to that particular achievement?

ALEX JOHNSON
Well, iron typically accumulates on the outside of a rice grain.  So you find a lot of iron in the outermost layers - this is the layer called the aleuron.  We also find a lot of iron in the embryo.  Those layers get polished off, typically, when rice is being produced, and so what’s left in the parts that we eat of the rice grain, called the endosperm, have very little iron.  We talk about iron in parts per million, and that endosperm tissue may have one to two parts per million iron.  

SHANE HUNTINGTON
In the particular process that you’re using, the entire plant absorbs more iron.  Is this helpful in terms of what we end up consuming?

ALEX JOHNSON
Yes.  This strategy works very well for us.  Previous groups have taken the gene I mentioned earlier, nicotianamine synthase, and they’ve expressed that specifically in the grain of plants.  And what we found is that does not really improve the concentration of iron in the grain.  So what we’ve done is we’ve turned on this gene in all tissues in all organs of the plant, and that helps us because it not only increases absorption of iron from the soil, but also increases transport of iron through the plant and ultimately into the grain.

SHANE HUNTINGTON
Sounds like the old approach though of going specifically for the grain was the logical one.  Why didn’t that end up with the result we were hoping for?

ALEX JOHNSON
Right. It made sense to try this strategy, because what we thought was by expressing nicotianamine specifically in the grain, we’d have a greater pool of iron into the grain.  That was the thinking in there and it does make sense.  But what happens is that there simply isn’t enough iron being delivered to the grain to enable it to be stored there.  So you have to attack the problem not only from the grain angle, but also from the whole plant, and increase delivery of iron to the grain and also increase its ability to be sequestered there.  

SHANE HUNTINGTON
I’m Shane Huntington, and my guest today is plant molecular biologist, Dr Alex Johnson.  We’re talking about the genetic modification of rice and other crops here on Up Close.  Alex, there’s been fairly extreme opposition to GM crops over the years from a variety of groups and in many regards we would say that the GM push has not been that successful around the world.  What crops currently exist and where are they successful? And do we have the kind of nutritional information coming back that says we should do this, this is valuable?

ALEX JOHNSON
GM crops have been in cultivation for more than 10 years now.  Even in Australia we have a significant number of GM crops that are cultivated.  Almost all of our cotton is GM, in fact, about 99.5 per cent of it last year was GM.  Ten per cent of our canola is also genetically modified.  We have GM crops in Australia.  Around the world we have large numbers of GM crops which have been modified for enhanced pesticide tolerance or modified herbicide tolerance.  So there is a big market for GM crops.  What we don’t have much of yet is nutritionally enhanced GM crops, but that is the next generation of genetically modified foods that we’re going to see on the market.  One which is to be released in the next year or two is a vitamin A enhanced rice, called Golden Rice, that many people will have probably heard about.  This is due to be released in the Philippines in the next year or two.

SHANE HUNTINGTON
The concerns from the public about GM crops is something that can’t be ignored and they’ve been around as long as this field has been in the public space, so they are significant.  How legitimate are they, and what do you think is the source of such a strong opposition to the introduction of these crops around the world?

ALEX JOHNSON
I think people are concerned about any aspect of food, actually, so any time you’re talking about making changes to food, people are concerned.  In all countries we have regulators that control the introduction of GM crops.  In Australia we have the Gene Technology Regulator, for instance, and the Gene Technology Act.  Those agencies would thoroughly investigate any food before it is released, but ultimately it’s up to every person to decide if they want to purchase a GM food.

SHANE HUNTINGTON
One of the concerns, I suspect, some people have is who’s funding this.  Often there is a very negative response when it’s found that large corporations are funding this sort of work.  In the case of what you’re doing, who are the funders?      

ALEX JOHNSON
In the case of what we’re doing - I work extensively with a program called the HarvestPlus Challenge Program.  This is a non-profit organisation which receives major funding from the Gates Foundation as well as many state governments.  And the sole goal of this organisation is to produce micronutrient enriched food staples.  So rice is one of their biggest targets because it feeds half the world.  But we also work with other staple foods such as maize and wheat and cassava. And we’re trying to increase not only iron concentrations, but also zinc and vitamin A.  And we are strictly going to release these crops into developing countries, there will be no IP held on these plants.

SHANE HUNTINGTON
Do we need to use genetic modification to achieve these biofortification goals or can we do it in another way? 

ALEX JOHNSON
We always try to use conventional breeding to develop any biofortified crop simply because that’s the more straightforward approach and there’s no different regulation associated with that approach.  We tried, as I mentioned, to use conventional breeding to increase iron in cereals and that has not worked, so there’s definitely a lack of genetic variation there and we’ve had to use genetic modification.  But if you look at other traits, like zinc, there is substantial genetic variation out there and we’ve been able to breed naturally a zinc enriched wheat and rice.  So it really depends on the trait that you’re looking at if you need genetic modification or not.  

SHANE HUNTINGTON
Alex, the work you’ve been doing has focused on bringing iron into the plants for nutritional purposes, but there are a number of other metallic ions that are also found in the soils where these crops are grown.  How do the changes that have been made in these particular plants affect the uptake of these other metallic ions that might actually, in some cases, be detrimental to our health?

ALEX JOHNSON
We’ve analysed our plants completely, not only for iron but for all types of metals.  Interestingly, what we found is that our approach increases not only the iron concentration of rice grain, but also zinc.  We’ve had about a twofold increase in zinc concentration.  Those are the two major metals that are increased via our strategy, but we’re also looking at other metals.  There’s a metal of concern always in agriculture, called cadmium, and this is a metal that can build up in soil and it can get into any cereal crop, and if it does it’s harmful to humans.  So we’re going to conduct field trials on cadmium contaminated soil over the next few years just to make sure that our plants don’t have enhanced uptake of other metals like cadmium.  But we have no evidence that that is occurring.

SHANE HUNTINGTON
This would seem to be a critical issue if you’re proposing to put these plants into the developed world because you would assume that they won’t necessarily have the capabilities to do the sort of soil toxicity measurements that would be required should the plants have this negative downfall.  What happens at that point, if you find out that cadmium is being absorbed, or other toxic metals are being absorbed?  What do you do then?      

ALEX JOHNSON
If we found that, we would change our strategy.  You wouldn’t want to put out a product that takes up harmful metals.  So simply that, it would not be a product we’d put out there, but we have no evidence that there is increased uptake of cadmium.  We’ve done glasshouse trials where we’ve actually put cadmium into our soil and there was no evidence of increased uptake.

SHANE HUNTINGTON
Now, some of the modern crop species that we’re seeing are grown all over the world and they’re quite varied.  Each region has its own varieties and we need to meet specific growing conditions.  How do you go about creating one variety that’s going to suit many communities in a way that will provide for this deficiency whilst dealing with climatic differences, soil differences and so forth?

ALEX JOHNSON
What we’ve done is we developed our iron enriched rice in one particular rice background, one particular variety of rice.  This is called Nipponbare rice, it’s a Japanese rice variety.  We’ve basically done proof of concept in that particular variety, and now what we’re doing is a process called backcrossing, where we’re taking that plant variety, in our best events in that variety, and crossing them to other rice varieties that are adapted to areas of Asia and areas of Latin America.

SHANE HUNTINGTON
Now, you mentioned there’s quite a long lead time from your laboratory through to the field to actually ending up on the supermarket or grocery shelf.  What sort of stage are we at with this work that you’re doing at the moment and when will we see these kind of enhances crops, in particular developing countries, where they’ll have the most impact?  

ALEX JOHNSON
We’re about five years into this project.  We started our work in 2007 and we now have a rice product that we verified has enhanced iron concentrations in the white rice grain, in the polished rice grain.  We’ve now started field trials and we’re in year 2 of these fields trials.  We’re running our field trials in Colombia at the International Center for Tropical Agriculture.  They have a very large GM rice field testing site - and also in The Philippines at the International Rice Research Institute.  We want to run these trials - we call them multilocation trials because they’re in The Philippines and Colombia - we want to run them for at least five years, and if all looks fine, if the iron stays high and the plants grow normally, we would then move them into our target countries like Bangladesh and East India to begin crossing them.  So we still are looking at about 10 years.

SHANE HUNTINGTON
Dr Alex Johnson, plant molecular biologist in the School of Botany at the University of Melbourne, thank you for being our guest on Up Close today and talking to us about biofortification in cereal crops.  

ALEX JOHNSON
Thanks for having me here, it’s been a pleasure.

SHANE HUNTINGTON
Relevant links, a full transcript and more info on this episode can be found on our website at upclose.unimelb.edu.au.  Up Close is a production of the University of Melbourne, Australia.  This episode was recorded on 7 March 2013.  Our producers for this episode were Kelvin Param and Eric van Bemmel.  Associate producer, Dyani Lewis.  Audio engineer, Gavin Nebauer.  Up Close is created by Eric van Bemmel and Kelvin Param.  I’m Shane Huntington, until next time, goodbye. 

VOICEOVER
You’ve been listening to Up Close.  We’re also on Twitter and Facebook.  For more info visit upclose.unimelb.edu.au.  Copyright 2013, the University of Melbourne.


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