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Far Eastern diners are partial to a variety of sweet, pink-skinnedtomato. Dr. Asaph Aharoni of the Weizmann Institute's Plant SciencesDepartment has now revealed the gene that's responsible for producingthese pink tomatoes. Aharoni's research focuses on plants' thin,protective outer layers, called cuticles, which are mainly composed offatty, wax-like substances. In the familiar red tomato, this layer alsocontains large amounts of antioxidants called flavonoids that are thetomatoes' first line of defense.
Some of these flavonoids also give the tomato cuticles a brightyellow cast -- the color component that is missing in the translucentpink skins of the mutants. Using a lab system that's unique in Israel, and one of only a few inthe world, Aharoni and his team are able to rapidly and efficientlyidentify hundreds of active plant substances called metabolites. Amultidisciplinary approach developed over the past decade, known asmetabolomics, enables them to create a comprehensive profile of allthese substances in mutant plants and compare it with that of normalones.
The research, carried out in Aharoni's lab by Dr. Avital Adato, Dr.Ilana Rogachev and research student Tali Mendel, showed that thedifferences between pink and red tomatoes go much deeper than skincolor: The scientists identified about 400 genes whose activity levelsare quite a bit higher or lower in the mutant tomatoes. The largestchanges, appearing in both the plant cuticle and the fruit covering,were in the production of substances in the flavonoid family. The pinktomato also has less lycopene, a red pigment known to be a strongantioxidant that's been shown to be associated with reduced risk ofcancer, heart disease and diabetes. In addition, alterations in thefatty composition of the pink tomato's outer layer caused its cuticleto be both thinner and less flexible that a regular tomato skin.
The researchers found that all of these changes can be traced to amutation on a single gene known as SIMYB12. This gene acts as a 'masterswitch' that regulates the activities of a whole network of othergenes, controlling the amounts of yellow pigments as well as a host ofother substances in the tomato. Aharoni: 'Since identifying the gene,we found we could use it as a marker to predict the future color of thefruit in the very early stages of development, even before the planthas flowered. This ability could accelerate efforts to develop new,exotic tomato varieties, a process that can generally take over 10years.'
artikel diatas slh satu cnth GM ( genetically modified ) food .Nk tnya pendapat korang sumer :pompom:
- sejauh mana keyakinan anda pada makanan yg berasaskan teknologi GM nie
- boleh bezakan tak mana satu makanan GM atau bukan GM jika ada di pasaran sekitar tempat tinggal korg
- adakah pembangunan teknologi GM nie berasaskn keperluan manusia atau kehendak manusia yg pelbagai
- kebaikan GM berbanding ciptaan asal Tuhan
jom share pendapat korg sumer  | 
Post time 17-1-2010 06:22 PM
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