A resource that we are increasingly using in our research is what’s known as the ‘1001 Genomes‘.
This is where the genome sequences for over 1000 different Arabidopsis plants are available for anyone to play with.
Just like you and me, we are all slightly different. Different hair colour, different height, different shoe size. The same is true for plants. The sequences for the 1001 genomes helps us work out how Arabidopsis has evolved, and might therefore help us understand how, for example, climate change will affect plants (and ultimately our food crops). For our research, we’re interested in how plants perceive and respond to temperature. How do plants survive and adapt to very different temperature environments? We can use the 1001 Genomes resource to help us address this question.
The flagship paper that describes this invaluable resource is a paper published by the 1001 Genomes Consortium in the journal Cell in 2016.
The paper shows that Arabidopsis ‘relict’ plants – something akin to the plant’s Founding Fathers – were prominent in the Iberian (Spain and Portugal) Peninsula – and seemed to hang about on the periphery of the last ice age (around 12,000 years ago), whereupon there was an expansion, or ‘sweep’ into more Northerly latitudes. What changes to the genome helped Arabidopsis survive in different habitats in their sweep North?
As pointed out in their Conclusion the authors state that “temperature and precipitation vary greatly across the species’ range and between groups and one would expect differences in physiological and developmental responses of Spanish and Swedish accessions”.
Why is all this important? Well, its been demonstrated that rice grain yield declines by 10% for each 1°C increase in growing-season minimum (i.e. night-time) temperature. One approach might be to therefore grow crops at higher latitudes, but by doing this our crops will need to adapt to different day-lengths. A higher latitude results in greater seasonality i.e. larger differences in day-length and temperature at higher latitudes compared to regions nearer the equator.
Why don’t we work directly with rice, wheat, barley, potato etc? Why do we work with Arabidopsis, which is a weed after all. Well the genome size of our staple crop plants are much bigger and more complex and so obtaining 1001 potato genomes would be a truly mammoth (and expensive) task. We also have a wealth of genetic resources available for Arabidopsis, And for me – never known for my horticultural skills – Arabidopsis is easy to grow (its a weed after all), and it lives and dies quickly (around 5 weeks) meaning that there can be a quick turn around of experiments.
There are some good web-resources that allows us to play around with the 1001+ sequences from all of these different natural variants. One that I find particularly useful is the SALK 1001 genomes browser, where you can plot all the single base pair changes across a gene region for as many of the 1001 genomes you can fit on your web-browser – see an example below.
Makes you wonder, looking at all of these small changes in DNA sequence – what do they mean for the plant, and how best do we test what these changes make?
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