The double life of a genome
Oxford University researchers captured a 'genetic snapshot' of maize as it existed 10 million years ago when the plant made a double of its genome – a 'whole genome duplication' event. They then traced how maize evolved to use these 'copied' genes to cope with the pressures of domestication, which began around 12,000 years ago. They discovered that these copied genes were vital to optimising photosynthesis in maize leaves and that early farmers selecting for them ‘fuelled’ the transformation of maize into a high-yield crop.
A report of the research is published this week in the journal Genome Research.
'Although whole genome duplication events are widespread in plants finding evidence of exactly how plants use this new 'toolbox' of copied genes is very difficult,' said Dr Steve Kelly of Oxford University's Department of Plant Sciences, lead author of the report. 'With crops like wheat it's not yet possible for us to unravel the 'before and after' of the associated genetic changes, but with maize we can chart how these gene copies were first acquired, then put to work, and finally 'whittled down' to create the modern maize plant farmed today.'
It is particularly useful for such genetic detective work that close relatives of maize did not duplicate their genomes 10 million years ago: those that retained a single copy went on to become the plant we now know as sorghum. This enabled the researchers to compare genetic data from these 'duplicated' and 'non-duplicated' descendants of ancient maize, something that is not yet possible with other duplicated crops like wheat.
In the wild plants have to overcome the challenges posed by pathogens and predators in order to survive. However, once domestication by humans began plants grown as crops had to cope with a new set of artificial selection pressures, such as delivering a high yield and greater stress tolerance.
'Whole genome duplication events are key in allowing plants to evolve new abilities,' said Dr Kelly. 'Understanding the complete trajectory of duplication and how copied genes can transform a plant is relevant for current efforts to increase the photosynthetic efficiency of crops, such as the C4 Rice Project. Our study is great evidence that optimising photosynthesis is really important for creating high-yield crops and shows how human selection has ‘sculpted’ copies of genes to create one of the world’s staple food sources.'
No comments posted yet. Be the first to post a comment
Please enter your name
Please enter your comment
Your comment submitted successfully.Please wait for admin approval.
Some error on your process.Please try one more time.
Membership of the EU is damaging the British farming industry, according to...
BASIS has launched an accreditation for pilots of Unmanned Aerial Systems (...
UK wheat yields have theoretical potential to more than double over the nex...
Britain’s farmers flocked to Peterborough for the first day of LAMMA’15 to ...
The crisis in the dairy industry is not the fault of supermarkets, accordin...
Transport Minister Baroness Kramer visited three rural businesses in Cheshi...
Spearheading the John Deere range of mid-size tractors from Mannheim, the n...
Regular testing for bovine TB could significantly reduce the number of infe...
Single-issue policy-making threatens to hamper, not help, the progress of U...