What do radiation, the International Atomic Energy Agency, and genetically modified organisms have to do with your food? A great deal actually, as I'm learning at the IAEA's current International Symposium on Induced Mutations in Plants. If you are interested in malnutrition in developing countries, Golden Rice, how plant breeders have produced a sizable fraction of the food you eat, and what this all has to do with the IAEA and radiation, please join me below the fold as I report on some of the astounding things I've learned from this meeting.
First, a question for you. How much of the plant based food you consume, do you think, is either genetically modified (meaning a gene from another organism has been inserted through biotechnological methods) or intentionally mutated, either with chemicals or radiation?
I unfortunately can't give you exact numbers, and the ones I'll give are at best approximations, but the answer is a lot. For GMO foods the USDA provides some numbers here. In the US, about 90% of the acreage devoted to corn and soybean is planted with genetically modified forms (also upwards of 80% of cotton). This is probably not surprising information if you've followed the debate around GMO foods at all.
What may be surprising is how much of the food you eat has been intentionally mutated, and hence, what the IAEA has to do with your food. Plant breeding is inherently no different than breeding dogs, cats, farm animals, or people for that matter. You take a population, find individuals with a desirable trait, and mate them. Frequently, their progeny will also contain the desired trait and you again mate the best ones (trying to avoid too much inbreeding where possible).
Beginning 80 years ago this month, plant scientists began to ask the question of whether we could take a given plant, mutate it, and randomly produce novel desirable traits. The answer, it turns out, is a pretty resounding yes.
Starting in the 1960s, the IAEA joined forces with the FAO, the UN Food and Agriculture Organization, in an atoms for peace project to use radiation to induce beneficial mutations in crops. Since then, approximately 3000 different varieties of approximately 70 different species have been produced through a wide variety of mutagenic techniques. Furthermore, this is almost certainly an underestimation as the FAO/IAEA database has strict requirements for inclusion. For example, sunflowers grown in the US and Europe have a high oleic acid content, the only known source for this mutation was a chemically induced mutant developed in Russia. Most modern sunflower varieties are almost certainly derived at least partly from this mutant, but there are only 3 varieties listed in the FAO/IAEA database.
I can pass along some numbers that were presented at the conference as to how much of the world's food supply is represented by these mutant varieties (all are in terms of acreage):
>20% of all acreage in China
>12,5% of all acreage in Japan
>55% of sesame in Korea
>51% of soybean in Vietnam
>80% of rice in Thailand
>30% of durum wheat in Italy
>70% of barley in Germany
and that's where I got tired of taking notes unfortunately. The list continued for quite a while.
How much of the food in the US is derived from these mutated stocks? I spent most of my evening asking google without much luck. The best I can do is this website which lists the names of some of the most successful varieties in the US (according to the IAEA we've produced 125 different varieties). Notable examples include Star Ruby and Rio Red varieties of grapefruit, which account for 75% of the grapefruits grown in TX. The other is Calrose 76, a semi-dwarf high yielding mutant of rice. Descendants of this mutant account for upwards of 50% of the rice grown in CA.
Induced mutagenesis is a completely haphazard, random process. Different mutagens produce different types of lesions, from single nucleotide changes to large chromosomal rearrangements and deletions. China even has a space breeding program that has produced at least 60 novel varieties of 8 different plant species. Gamma rays, X-rays, fast and slow neutrons, toxic chemicals, iron and carbon ions from particle accelerators - if it causes DNA damage, someone has probably used it on a plant to study the mutations it will produce and selected for any beneficial mutation.
These tools allow breeders to induce novel mutations for any physical trait they can imagine. Amount of useable product produced, when the plant flowers, how long it takes to grow, salt and drought tolerance, submergence tolerance in rice, taste, color (this is a biggie for chrysanthemums, I had no idea how large the ornamental flower industry is), how easy it is to harvest, pest resistance. If the scientists can measure it, they can induce mutations in it. There are, however, some limits that we'll get to in a minute.
I spent a large portion of the morning in a discussion of biofortification, that is, breeding plants to have more of a few essential nutrients, namely provitamin A, iron, and zinc. Much of this work is being coordinated and designed by Harvest Plus.
The numbers are sobering. 2 billion people are anemic due to iron deficiency and approximately as many are iron deficient but not anemic. Not only does anemia leave people constantly tired, but iron deficiency in children impairs growth, mental development, and learning. Perhaps as many as 100,000 mothers die during child birth every year due to lack of iron.
Almost the same number are deficient for zinc, a micronutrient important for the immune system and growth - lack of zinc can lead to stunting and is a significant risk factor for diarrhea, which wikipedia tells me is the second leading cause of infant death worldwide.
Viatmin A deficiency affects as many as 250 million children worldwide. Of these, half a million (just think of that number) go blind every year, and approximately half of those die. 250,000 little kids, each and every year.
HarvestPlus is working with breeders and scientists to try and develop staple foods (rice, corn, sweet potato, cassava, etc) that contain higher levels of these essential micronutrients, and induced mutagenesis has and will continue to be an important tool for them to select for biofortified varieties of these plants.
As I mentioned before, however, there is only so far induced mutations can take us. Golden rice is perhaps the best example. Rice lacks several key genes for production of provitamin A. While it is theoretically possible to mutate rice until it produced those genes (1000s of monkeys on 1000s of typewriters and all) it is practically impossible. Using transgenic techniques, however, it is almost trivial. Over the last several years, rice containing a gene from bacteria and one from corn has been produced that would essentially eliminate vitamin A deficiency in children who consume 150g a day (apparently typical of many rural asian children). A GMO food that could conceivably save the lives of a quarter of a million children a year, and its been stuck in the lab since 2005, and will probably not reach farmers until 2012. 7 years times a quarter of a million kids a year is a large number. Below is a quote from Ingo Potrykus on why its taken so long (full statement here and more on golden rice here).
It is also true that "perceived risks" are a major barrier and it is good to read that there is no scientific justification for this perception. Indeed, after 25 years of biosafety research and regulation there is a wealth of clear scientific evidence as well as a scientific consensus that there is no inherent and specific risk associated with the technology. If someone claims the contrary, either he or she does not know the scientific literature or is lying .But I agree that there is the perception of risk which has to be accepted as a psychological fact. It should be up to governments to inform their people about what is right and what is wrong. But all this is nevertheless not the major reason for the "slow progress".
Where I can not at all agree is the notion that "weak regulatory capacity" is a major cause. It is true that regulatory authorities may have a negative impact. However, not because of weak capacity, but because of the principle of "extreme precautionary regulation". People involved become frightened of making a mistake, leading to the psychological situation that it is better not to take any decision at all rather than one which could be criticised by the GMO opposition.
The overwhelming cause for the "slow progress" is, however, the system of "extreme precautionary regulation" established around the world. Lacking any scientific justification, this regulatory system prevents use of GMO technology for the benefit of the poor; everywhere it paralyzes public institutions, specifically those in developing countries.
In the specific case of Golden Rice, a humanitarian project developed in the public domain, supported by the private sector and with the proven capacity of saving in India alone up to 40,000 lives a year [2], we experienced a delay in the adoption so far of seven years, solely because of regulatory requirements. It is probably fair to say that GMO regulation, in the context of Golden Rice, is responsible for the loss of 7 x 40,000 lives in India and, of course, of many more in the other countries.
I am not aware of any hypothetical risk stemming from Golden Rice (or actual risk from any GMO) which would justify this loss of life. The cost of taking a single transgenic event through the regulatory process is about US$ 20 million. In summary: compared to introducing a new non-transgenic strain, one single transgenic event with a pro-poor trait and in a pro-poor crop costs about 10 additional years of work and US$ 20 million.
Golden Rice will be in the hands of farmers from 2012 onwards, i.e. 13 years after the scientific proof-of-concept had been established. No public institution and no scientist in the public domain can afford to spend 10 years of an academic career on a project with so small a chance of publication; no public granting institution is willing to invest such an amount of funds into product development and deregulation of one single event, even if proof-of-concept has been established and there is a potential of saving millions of lives.
And finally we're at the real point of this diary. Plant breeders, for at least the last 40 years, have been blasting the world's food supply with every mutagen known to man, looking for any and every beneficial trait to breed into crops and with absolutely no idea of what other mutations are being dragged along with the beneficial trait. In contrast, a GMO like Golden Rice, well designed and well studied, is stuck for decades behind regulatory hurdles.
I guess thats about all I had to say. I've certainly learned a lot at this meeting and I hope I've managed to pass along a little bit of that knowledge. I'll leave you with one more factoid that was mentioned (and it seems implausible, but the guy who said it was an expert)
Two different inbred lines of maize can be more genetically different than humans and chimpanzees. If true, I think its pretty amazing.