Scientists at the
University of Oxford have
paved the way for bigger and better quality maize crops by
identifying the genetic processes that determine seed
development.Plant scientists have
known for some time that genes from the maternal plant control
seed development, but they have not known quite how. The Oxford
research, supported by the
Biotechnology & Biological Sciences Research Council (BBSRC)
and highlighted in the new issue of BBSRC Business, has found at
least part of the answer.
Working in collaboration with
researchers in Germany and France, Professor Hugh Dickinson's
team found that only the maternal copy of a key gene responsible
for delivering nutrients is active. The copy derived from the
paternal plant is switched off. This gene encodes a potential
signalling molecule found in the endosperm - a placenta-like
layer that nourishes the developing grain, which is involved in
'calling' for nutrients from the mother plant, and so triggers
an increased flow of resources. Similar mechanisms can almost
certainly be expected in other cereals, and with cereal grain
being a staple food across the world, the potential to harness
this science to improve yields is clear.
Prof. Dickinson explains: "By
understanding the complex level of gene control in the
developing grain, we have opened up opportunities in improving
crop yield.
"The knowledge and molecular tools
needed to harness these natural genetic processes are now
available to plant breeders and could help them improve
commercial varieties further. For example, they can better
understand how to successfully cross-breed to produce higher
quality crops. The cereal grain is a staple food of the world's
population: with the changing climate and growing population,
the need for sustainable agriculture is increasingly pressing."
The mechanism used to switch off
paternal genes ensures supremacy of maternally-derived genes.
This process is known as 'imprinting' and is achieved mainly
through 'methylation' - a naturally occurring chemical change in
the DNA. A very similar mechanism takes place in animal embryos.
However, unlike the animal imprinting systems where genes are
often grouped in the chromosomal DNA, in maize imprinted genes
are 'solitary' and independently regulated.
This project was a collaboration between
the University of Oxford's Department of Plant Sciences,
researchers at the University of Hamburg and
Biogemma, a French
biotech company.
It was funded initially through the EC Framework Programme V,
and then under BBSRC's initiative on Integrated Epigenetics.
The Biotechnology and Biological Sciences Research Council
(BBSRC) is the UK funding agency for research in the life
sciences. Sponsored by Government, BBSRC annually invests around
£380 million in a wide range of research that makes a
significant contribution to the quality of life for UK citizens
and supports a number of important industrial stakeholders
including the agriculture, food, chemical, healthcare and
pharmaceutical sectors.
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