Oct31

Whose line is it, anyway?

Author // Dr. Robert S. Zeigler Categories // Bob's blog

Dr. Sigrid Heuer being interviewed on BBC.

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The title of this long-running BBC comedy program popped immediately to mind as I read an article in the IRRI Bulletin a few weeks back. It was a piece about a bit of a kerfuffle over the origin of a traditional variety that was the source of a newly discovered gene conferring phosphorus uptake efficiency in rice. The scientific work by IRRI scientists and colleagues was published in the top-flight journal Nature and drew headlines around the world. The importance of increasing the efficiency of phosphorus uptake and use in rice is tough to overstate since phosphorus is such an important plant nutrient, supplies may be limited in the future, and it is associated with serious pollution when it is misused. And, even better, the gene may be useful in other cereal species as well. The lead scientist, IRRI’s own Dr. Sigrid Heuer, was even interviewed live on BBC.

The gene was identified in a traditional variety, Kasalath, originating from South Asia. Seed was obtained by the scientists and it is described as being from India. In the paper, the authors indicated this as the variety’s origin, much to the chagrin of colleagues from Bangladesh, who proudly claimed it as their native son or daughter – by the way, it’s tough saying fathers, sons, mothers, and daughters for self-pollinating cereals. See “Origin of the rice variety Kasalath” for a concise and diplomatic treatment of the disagreement around Kasalath’s origin. I think, however, that this discussion actually raises some very important (and really interesting) questions about the origins of rice varieties. The answers to these questions can help us navigate the bewildering complexity of rules we now face in a world of conventions and treaties around biological diversity. And, ultimately, how can we be sure that the best traits in rice can have the widest possible use?

First, the specifics: Kasalath is neither an “Indian” nor a “Bangladeshi” variety. It seems to have been created by farmers from the region that now includes parts of Bangladesh, parts of Assam (India), and perhaps even West Bengal (India) and other eastern Indian states. Also, I would be willing to bet that it, or its close ancestors, has been around for centuries or longer. So, really, Kasalath, like so many of the 100,000+ traditional varieties held in trust in the International Rice Genebank, is a gift to our generation from farmers who lived and died centuries ago. These particular farmers were possibly living in one of the great South Asian kingdoms called Harikela, and the region is even referred to in ancient Hindu Tantric texts. Frankly, I find it quite a bit more uplifting to consider Kasalath as having come to us over the centuries from distant kingdoms than to quibble over whether it is “from” one present-day country or another.

More generally, research over the past five years or so is shedding tremendous light on the origins of genes conferring valuable traits such as aroma (Aroma genes in Thai jasmine rice abundant across Asia) and even around the way rice itself was domesticated. This work is possible because we are now able to generate partial and even complete DNA sequences of hundreds or thousands of rice varieties and compare “the interesting parts.” What this is showing us is that some genes have had different mutations selected by farmers in very distant parts of Asia to conserve the same novel trait, such as aroma. Some mutations are “stronger” than others and have spread around the world; nonetheless, numerous different ones for the same trait have been conserved by farmers over hundreds, if not thousands, of years. A remarkable finding is that there has been extensive movement of these mutations – OK, new alleles or traits sound much nicer – across large areas and even among subgroups of rice that were earlier thought to be pretty much isolated from one another. So, farmers were exchanging interesting new rice traits just as they do today, but rice seed must have been moving along, first, human migration routes, and then along the earliest ancient trade routes from the very beginning of modern humanity.

At a more rarified level of variation in that plant we call “rice,” the discussions around where and how it became domesticated are heating up. It is generally agreed that rice (Oryza sativa) was domesticated (read: farmers took the good stuff and saved seed) from Oryza rufipogon, an aquatic grass that still grows widely across Asia. The two major subgroups, indica and japonica, were thought to have been the result of separate domestication events. The frustration of modern breeders with the difficulty of crossing between these two groups to exchange useful traits was considered to be strong evidence for this. But, recent work suggests that there may have been only a single domestication center in China. (For rice, it was never a single “Aha!” moment in a field as it may have been for wheat.) That work suggests that, as rice moved across Asia, it continued to cross with its wild progenitor, taking in new genes and rearranging them for the cleverest farmers to select.

So, although the crucial push by farmers to move O. rufipogon to a much more farmer-friendly O. sativa may have begun in a river valley in China, all work still points to continuous movement of O. rufipogon genes into the increasingly domesticated O. sativa. As farmers, migrants, and traders carried and planted seed across Asia over millennia, new combinations of existing genes, new mutations, then combinations, and the addition of new genes from their wild ancestors combined to give us the beautiful diversity that is rice. This genetic exchange continues as you read these words. We hold a snippet of this in IRRI’s T. T. Chang Genetic Resources Center.

So, to come back to the original question: “Whose line is it, anyway?” I think the answer lies in the dismissive last word of the question: “anyway.” There is no “variety” Kasalath. There is a seed sample in a few genebanks collected from a farmer’s field that is a subsample of the diversity of what farmers have been growing for a very long time. What that means is that what we have in IRRI’s Genebank is not unique. (Full disclaimer: That does not mean it is not important. The individual accessions are traditional varieties that capture unique combinations of many, many mutations and recombinations that together create their value that farmers preserved for their specific purposes. The individual building blocks, or "heritable units", may be rather widespread within cultivated rice and in a sense, then, may not be all that special in their own rights.)

I would expect that many of the genes, alleles, mutations … you name it … that will be of increasing interest are in our Genebank, but also in other varieties or breeding programs around the world. The International Treaty on Plant Genetic Resources for Food and Agriculture stipulates that any “heritable unit” received from our Genebank will be subject to the rules of the Treaty (which are good, in my opinion). But, that same “heritable unit” exists in countless copies and versions outside our Genebank, and those are completely outside the jurisdiction of the Treaty. So, I predict that the provisions of the Treaty will become meaningless. For those of us who care that the intention of the Treaty – free access to all for the benefit of all – is maintained, we must take a hard look at the biology of the rice plant, agriculture, and, yes, business, to balance opportunity, need, and obligation.

So, who “owns” the genes and gene combinations that farmers created and shared, and migrants and traders carried across thousands of kilometers? Whose line is it, anyway? I refer you to the great American songwriter, balladeer, and folk singer, Woody Guthrie. He wrote a song I sang in grammar school, whose significance I am still absorbing: “This Land Is Your Land.” (click on the Youtube link)

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About the Author

Dr. Robert S. Zeigler

Dr. Robert S. Zeigler

Dr. Robert "Bob" Zeigler is an internationally respected plant pathologist with more than 30 years of experience in agricultural research in the developing world. He is the first Director General Emeritus of IRRI.

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