1. ESRC Genomics Network (archive)
  2. Gengage
  3. The Human Genre Project

Egenis · News

Wheat Genomes: Chinese Spring lifts gloom



Co-director Steve Hughes gives a cautious welcome to the sequencing of the wheat genome.


Wheat has been prominent in the news lately in relation to future food security (writes Professor Hughes). For those of an optimistic disposition, the announcement(s) of the completion of a draft DNA sequence representing more than 95 per cent of the genome of the wheat variety Chinese Spring as an opening of the door to a new proposition for the breeding of improved varieties, possibly countered the woes from elsewhere such as the land grab for biofuels in Africa. After all, wheat is an adaptable food source, consumed across all the continents, with a global annual harvest of around 650 million tons and well worthy of having the best of genomics and enhanced breeding technologies on its case. Celebrate we should, but with perhaps a careful look at the broader perspective of institutional practices in the food chain.

The technical achievement of the seaquenicng achievement, supported by the Biotechnology and Biological Science Research council (BBSRC), is outstanding. The lean UK team made optimum use of the latest generation of high throughput sequencing platforms (Roche454) and achieved in one year what would have been expected to take 10 only a few years back. Adopting a shotgun approach (the sequencing of random fragments sufficient to represent the wheat genome five times over) and a platform which allows long sequence readouts, the team were able to use overlaps to assemble the complete sequence (at least 95 per cent of it). This provides a framework for their next objective, which is to sequence the genomes of many more diverse wheat lines using even more high throughput but short readout sequencing platforms (SOLiD) to discover the sequence differences (single nucleotide polymorphisms or SNPs) associated with their special traits. This will undoubtedly reinforce the breeder’s arsenal and extend the informational base for designing breeding programmes and selection strategies to facilitate the development of radical new varieties. But the path is not as simple and linear as this account suggests. It will take some time and will require inputs from other actors.

This reservation underlines the objections to some of the more hyped and speculative press coverage of the achievement, in particular that of the Associated Press report, articulated in a press release signed by 40 or more members of the International Wheat Genome Sequence Consortium. IWGSC weigh in with a stern rebuke representing the achievement as still a few loaves short of a miracle picnic. To dismiss this as upstaged sour grapes, as I was tempted to at first, might be to miss out on the interesting aspect of the story which lies in its similarity to the tale of the human genome sequencing initiatives and the issues of open access.

The IWGSC, paying due reverence to the fact that the wheat genome is a complex composite of three ancestral grass genomes and is six times larger than the human genome, has been soldiering on having adopted a distributed map-based chromosome by chromosome approach. The labour is shared between teams in several countries with the goal of producing a fully annotated sequence and gene map, with no end date in sight. The contrast between this and the accelerated shotgun approach embraced by the BBSRC team is reminiscent of the contest between Craig Venter’s Celera Genomics’ private, shotgun approach to sequencing the human genome, which started life as a hunt for SNPs, and the internationally distributed map-based approach of the Human Genome Project- HGP (Dr Adam Bostanci has written a very readable account of this relationship). Ultimately the latter contest was resolved as a draw in a very public celebration, with glory shared, but tension remains over the issues of intellectual property. It is suspected that the shotgun approach enabled extensive annexation and premeditated patenting of the draft human genome sequence in advance of its public release, whereas the HGP sought, in the spirit of the Bermuda Principles (see: http://clinton4.nara.gov/WH/EOP/OSTP/html/00314.html) to ensure that the sequence remained accessible and unrestricted in the public domain. Notably, this is where the human and wheat stories diverge. The BBSRC team have emphatically placed their data immediately in the public domain for use without restriction save the preemption of their forthcoming publication and analysis. This would be most reassuring, were it not that significant potential restrictions to the deployment of this data and knowledge for public goods like food security, reside elsewhere in the institutional chain of application.

This was starkly brought into focus in the other wheaten story which appeared around the same time. It was announced from Australia that InterGrain Pty Ltd and Monsanto have made an agreement to cooperate on wheat breeding. The agreement embodies the sharing of germplasm and an input of breeding technology (from Monsanto) as well as a capital stake for Monsanto. The implication is that the diversity which the BBSRC team seeks to analyse and mark genetically in support of enhanced breeding is the stuff of private deals and ownership, and so are the technologies for its management in breeding projects. A quick search of the patent literature reveals filings relevant to the use of sequence data in the tagging of traits for genomically informed breeding so we would do well to be concerned about freedom to operate in the newly drawn landscape of the wheat genome.

Intergrain and Monsanto have highlighted a systemic institutional issue. The best of our public genomic initiatives will little serve the cause of food security unless access to contemporary germplasm and other sources of novel traits is assured. Acting against this, as we have noted (see: http://www.tailoringbiotechnologies.com/2_3_Hughes_Deibel.pdf) are the competitive breeders’ instincts to cast a mantle over their breeding material, the corresponding and justifiable reluctance of farmer breeders to let their field varieties (which amount to work in progress) be sucked into international collections and the general friction inherent in the market-oriented material transfer agreements which now govern germplam exchange.

Plant breeding supported by skilled and well-resourced breeders is vital to food security. Access to current germplasm is key to bringing the best of genomic tools into that resource and much too important to be left to markets.