Foreign genetic material in long-lasting tomato
- Details
2.India's new delicacy: a 45-day-old tomato
EXTRACT: "There is no alien gene in these tomatoes." (item 2)
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1.COMMENT from Dr Michael Antoniou, Head: Nuclear Biology Group, King's College London
(Comment on PNAS publication Enhancement of fruit shelf life by suppressing N-glycan processing enzymes, Vijaykumar S. Meli1, Sumit Ghosh1, T. N. Prabha, Niranjan Chakraborty, Subhra Chakraborty, and Asis Datta, National Institute of Plant Genome Research, New Delhi 110067, India)
These GM tomatoes are very much a product of standard transgenic procedures. The lead author is being quite disingenuous when he says there are no foreign genes in these GM tomatoes. They contain two foreign stretches of genetic material encoding what are known as RNAi sequences (expressed from our old friend the CaMV promoter). These RNAi "genes" do not produce any new protein, which is why he is saying that these GM tomatoes don't contain any foreign "gene". But they do contain transgenes whose products (small RNA molecules) are able to target and partly switch off ("knock-down") expression of selected genes, here those involved in tomato ripening.
So in general all our concerns about adverse events arising from the mutagenic effect of the GM transformation process apply equally here as they do in any other GM crop, which does express a foreign protein. In addition, RNAi is not perfect and is proven to have "off-target" effects; i.e, these RNAi molecules can have knock-down effects on genes other than those they are designed to target. I can guarantee you that if a thorough and proper analysis of the gene expression, protein composition and metabolic profile of the GM and non-GM equivalent tomatoes was conducted they would be major differences found between the two. And adverse health effects in long-term animal feeding studies? I'll leave you to bet on this!
By the way, all this is really deja vu; two varieties of delayed ripening GM toms were produced many years ago, one by what was then Zeneca Plant Sciences (which got sold as tomato puree in Sainsbury's and Safeway) and the other being the infamous "FlavrSavr" tomato by Calgene (later bought by Monsanto). These were the first GM crops on the market launched in 1994, although both were removed from the market many years ago. (The FlavrSavr lacked flavour and bruised during harvesting and was a commercial failure; Sainsbury's and Safeway discontinued their GM tomato puree after public rejection of GM foods in the late 90's in the UK and Europe).
So in summary, what we are seeing here is the same outcome but via a different type transgene and molecular mechanism. But we should be as worried about these GM fruits to the same extent as with any other GM crop as they are definitely a product of a standard GM transformation process.
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2.India's new delicacy: a 45-day-old tomato
Andrew Buncombe in Dehli
The Independent, 9 February 2010
http://www.independent.co.uk/news/world/asia/indias-new-delicacy-a-45dayold-tomato-1893333.html
In a country where so many people go hungry, it is a dark irony that up to 30 per cent of the fruit and vegetables grown in India goes bad before reaching the market thanks to a combination of bad roads and a lack of refrigerated trucks.
But scientists in Delhi believe they have found a solution, or at least part of the solution. Modification of a tomato - but a modification that does not require the introduction of foreign genes - has extended the life of the fruit to up to 45 days. Indeed, the scientists at the National Institute of Plant Genome Research (NIPGR) believe they may have produced the world's longest lasting tomato.
"We're not adding new genes into tomatoes the shelf life is increased by silencing two genes that make the fruits go soft," said the institute's senior scientist, Asis Datta. "Think about a normal tomato that can last a maximum of 15 days. This can last for 45 days without any problem. It is good news for the common people."
According to details published in the Proceedings of the National Academy of Sciences, Professor Datta and his colleagues identified two plant enzymes and their genes that drive fruit ripening. Then they used a process known as RNA-interference to "silence" the genes. As a result, the shelf-life of the tomatoes was extended threefold.
The researchers believe the process could be extended to other fruits such as mangoes, papayas and bananas which all suffer similar problems of getting to the customer in good condition.
The scientific breakthrough comes at a time of mounting controversy for genetically-modified food. The government is completing a series of public consultations on the introduction of a genetically-modified aubergine in the country, developed in part by Monsanto, the US-based bio-technology giant. It has been approved by a scientific panel but is being opposed by activists.
This weekend, the country's Environment Minister, Jairam Ramesh, was faced with more angry reaction from farmers and activists. At one point he was accused of being "an agent of Monsanto" and he swapped heated comments with his heckler, who was eventually removed by police.
The government is due to make a decision in days. "The decision will disappoint 50 per cent of India, and the rest will be happy," said Mr Ramesh. "But my decision will be based on balancing science and society. Public opinion is very important. We should always remember that [this] is the first genetically modified vegetable in the world."
While Professor Datta's tomato would have to receive similar approval before it could be introduced, he said he did not think it would create controversy. He said he believes the review process could be completed in as little as two years. He stressed: "There is no alien gene in these tomatoes."