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[SANET-MG] genetic technology supports? eek
The article below uses a cruel twist on an important finding.They might have ,
at least, admitted, organic is superior!
Genetic technology supports sustainable farming
- THE ECONOMISTJul 8th 2004
NEW genetic technology may not only help to bolster traditional
selective-breeding techniques. It may also, horror of horrors, have a role in
the sort of "sustainable" farming favoured by opponents of high-tech
agriculture. For biotech has now shown that there are differences betweenthe
molecular biology of sustainably grown crops and those grown using modern
agricultural techniques. Moreover, those differences favour the sustainably
Autar Mattoo and his colleagues at the American Department of
Agriculture'sVegetable Laboratory have been comparing mulching methods for
tomato crops.As they observe in the Proceedings of the National Academy of
Sciences, theyhave identified differences in the ways that tomato plants
express theirgenes, depending on whether those plants are grown on a black
polyethylenemulch and fed with synthetic fertiliser (the method favoured by
conventional modern horticulture) or by using a mulch made from a leguminousu
plant calledhairy vetch (which is favoured by the proponents of
Black polyethylene mulching involves the plants growing through holes inplastic
sheets that cover the soil. The sheets keep the soil moist and warm,and also
stop weeds growing. Hairy-vetch mulch does all of those things,too, but using
it is not as convenient as laying down a few sheets ofplastic, and is more
expensive. On the other hand, plants grown using hairy-vetch mulch are a lot
healthier (and yields are 20% higher), so Dr Mattoo wondered if he could track
down the biochemical origins of this healthiness.
To look at the activity of the plants' genes, Dr Mattoo used a modern genetic
technique called cDNA subtraction cloning. This works by making copies of the
messenger molecules that carry information from the genes in acell's nucleus to
the protein factories in its outer reaches. The more messengers there are from
a particular gene, the more active that gene is.The copies of the molecular
messengers are known as complementary (or "c")DNAs, and by employing suitable
chemical trickery, it is possible to comparethe cDNA profiles of two plant
tissues by, in effect, subtracting one from the other, so that only the
Using this technique, Dr Mattoo found a number of genes that expressed
themselves more vigorously in plants grown on hairy-vetch mulch, rather than
black plastic. These genes included those involved in photosynthesis,disease
resistance, defence against pests and the assimilation of nitrogen.All of this
helps to explain the more vigorous growth of hairy-vetch-mulched plants.
What is not explained, however, is why these genes express themselves
vigorously. But Dr Mattoo has a hypothesis. Among the healthiest parts ofthe
hairy-vetch-grown plants are their roots. These are a source of hormone swhich
affect gene expression. More roots, more hormones, and more expressive genes.
One up to sustainability.
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