New Zealand
March 4, 2008
Source:
Crop & Food Research
Digest, Issue 60 - 2008
A scientific breakthrough which
puts ‘tearless’ onions within reach of consumers within a decade
has put New Zealand research on the international media map this
year.
Crop & Food Research senior
scientist Dr Colin Eady and his collaborators in Japan have been
testing tearless onions in the laboratory and last year
presented their results to the 5th International Symposium on
Edible Alliaceae, in the Netherlands.
Dr Eady describes ‘tearless’ onions as being in the
developmental stages but if the research progresses well, would
like to see them become the household and industry norm within
the next decade.
It’s a story which has piqued the interest of media around the
globe, with strong international coverage in major newspapers
and broadcast media.
Dr Eady says the research is based on a gene-silencing
technology, called RNAi, developed by Dr Peter Waterhouse at
CSIRO in Australia. “This allows us to retarget the plant’s own
natural regulation system without expressing foreign proteins in
the plant,” Dr Eady says.
“Through RNAi, genes can be specifically shut down or turned
off. By shutting down the lachrymatory factor synthase gene, we
have stopped valuable sulphur compounds being converted to the
tearing agent, and instead made them available for redirection
into compounds, some of which are known for their flavour and
health properties.”
Dr Eady says the research team has been unable to induce tearing
by crushing their model tearless onions.
“What we have now is unique germplasm with a unique trait. We
can home in and study what the consequences of this one effect
are. We can detect differences in sulphur compounds known to be
involved in flavour and health and actually measure them and
assign a role to them.”
International onion trade journal Onion World featured Dr Eady’s
work on the front cover of its final issue for 2007. The
magazine quotes Dr Michael J. Havey, Professor of horticulture
at the University of Wisconsin and USDA research geneticist, as
well as a world-renowned onion scientist, as predicting that
tearless onions will become a mainstay in household kitchens
around the world. He said Dr Eady’s work was “clearly the No. 1
topic of discussion at the 5th International Symposium”.
Dr Eady says although the “tearless onion” is an exciting
project, he is most interested in sustainable and efficient
production and will want to be sure that the onions he is
working on are also capable of being grown in an efficient
manner. “We have a burgeoning population to feed, and with
climate change and other challenges, available resources are
being reduced. The gene silencing system can also be used to
combat viruses, diseases and biotechnology in general can help
us produce more robust crops.”
Dr Eady says in many countries onions already contribute a
significant proportion of daily fibre requirements. “They are
such a versatile and nutritious vegetable, so if we can manage
to get more people cooking and eating fresh onions, then that
has got to be a positive outcome.” |
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