NEWS
How our plants have turned
into thieves to survive
University of Sheffield
Current Address: University of Sheffield
Reprinted From: http://bit.ly/2QrLQcS
S
cientists have discovered that grasses
are able to short cut evolution by tak-
ing genes from their neighbours. The
findings suggest wild grasses are naturally
genetically modifying themselves to gain a
competitive advantage.
Understanding how this is happening may
also help scientists reduce the risk of genes
escaping from GM crops and creating so
called "super-weeds—which can happen
when genes from GM crops transfer into
local wild plants, making them herbicide
resistant.
Since Darwin, much of the theory of evolu-
tion has been based on common descent,
where natural selection acts on the genes
passed from parent to offspring. However,
researchers from the Department of Animal
and Plant Sciences at the University of Shef-
field have found that grasses are breaking
these rules. Lateral gene transfer allows or-
ganisms to bypass evolution and skip to the
front of the queue by using genes that they
acquire from distantly related species.
"Grasses are simply stealing genes and tak-
ing an evolutionary shortcut," said Dr. Luke
Dunning.
"They are acting as a sponge, absorbing
useful genetic information from their neigh-
bours to out compete their relatives and
survive in hostile habitats without putting
in the millions of years it usually takes to
evolve these adaptations."
Scientists looked at grasses—some of the
most economically and ecologically im-
portant plants on Earth including many of
the most cultivated crops worldwide such
as: wheat, maize, rice, barley, sorghum and
sugar cane.
The paper, published in the journal Pro-
ceedings of the National Academy of Sci-
ences, explains how scientists sequenced
and assembled the genome of the grass
Alloteropsis semialata.
Studying the genome of the grass Alloter-
opsis semialata - which is found across Af-
rica, Asia and Australia - researchers were
able to compare it with approximately 150
other grasses (including rice, maize, millets,
barley, bamboo etc.). They identified genes
in Alloteropsis semialata that were laterally
acquired by comparing the similarity of the
DNA sequences that make up the genes.
"We also collected samples of Alloterop-
sis semialata from tropical and subtropical
places in Asia, Africa and Australia so that
we could track down when and where the
transfers happened," said Dr. Dunning.
"Counterfeiting genes is giving the grass-
es huge advantages and helping them to
adapt to their surrounding environment and
survive - and this research also shows that
it is not just restricted to Alloteropsis semi-
alata as we detected it in a wide range of
other grass species"
"This research may make us as a society
reconsider how we view GM technology as
grasses have naturally exploited a similar
process.
"Eventually, this research may also help us
to understand how genes can escape from
GM crops to wild species or other non-GM
crops, and provide solutions to reduce the
likelihood of this happening."
"The next step is to understand the biologi-
cal mechanism behind this phenomenon
and we will carry out further studies to an-
swer this."
More information
Luke T. Dunning el al., "Lateral transfers
of large DNA fragments spread functional
genes among grasses," PNAS (2019). www.
pnas.org/cgi/doi/10.1073/pnas.1810031116
Journal information: Proceedings of the Na-
tional Academy of Sciences
012 748 6500
www.sacnasp.org.za
Grassroots
Vol 19
No 4
November 2019
30