Brave scientists from the New Zealand Institute for Crop and Food Research used RNAi to disable the lachrymatory factor synthase gene in an onion, resulting in an onion for sissies:
International attention is focusing on “tearless onion” research being conducted by senior Crop & Food Research scientist Dr Colin Eady.
Dr Eady and his collaborators in Japan have been testing tearless onions in the laboratory and have presented their results so far 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.
“We have been using a gene-silencing technology, called RNAi, developed by Dr Peter Waterhouse at CSIRO in Australia, that 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 a truly 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 to them a role.”
International onion trade journal Onion World is featuring 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 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”.