The work of Israeli geneticists

Jul 5, 2007 09:40 GMT  ·  By

Geneticists seem determined to get the animal that would be the perfect pet while delivering us milk, wool, skin, meat, honey, silk and the perfect crop that will deliver us eatable fruits, seeds, tubers, roots, leaves, flowers and so on.

Till then, Israeli scientists have genetically engineered tomatoes to which they added hints of lemon and rose aromas that have passed well testing made on volunteers. The research team led by Efraim Lewinsohn of Newe Yaar Research Center engineered tomatoes in whose genome they included a gene from a variety of lemon basil, Ocimum basilicum that synthesizes an aroma-making enzyme named geraniol synthase.

82 volunteers have tested the experimental fruit against unmodified counterparts. Almost all of them could pick up new aromas, which they variously described as "perfume", "rose", "geranium" and "lemongrass". When asked about their preference, 49 subjects preferred the engineered tomatoes, while 29 chose unmodified tomatoes and four had no preference. The new tomatoes display just a light red color, as they contain just half as much lycopene as conventional tomatoes. Besides giving an intense red color to tomatoes, lycopene is an antioxidant, a group of chemicals considered to induce beneficial effects on the organism.

"Offsetting the low levels of lycopene are higher levels of compounds called volatile terpenoids, which possess antimicroial, pesticidal and antifungal qualities, so the GM tomato may have longer shelf life and need less pesticide to grow," explained Lewinsohn.

The Israeli researchers point that other crops and flowers that, like tomatoes, synthesize large amounts of carotenoids could also be genetically modified to shift their scent and flavor.

The first engineered tomato, named FlavrSavr, reached the US market in 1994. It had inserted a gene linked to the fruit softening process, so that the tomato could be allowed to ripen on the vine and had a longer shelf life, but it was a selling failure and currently no engineered tomatoes are being traded in US.