Biotech Updates

GM Tomato with Improved Antioxidant Activity and Zinc Content

October 31, 2007

Metallothioneins (MT) is a family of metal binding-proteins widely distributed in plants, animals and microorganisms. They function in detoxification of heavy metals as well as control of oxidative stress by capturing free radicals. Foods with high levels of MTs have potentials as functional foods. By introducing the gene mt-1, coding for the mouse metallothionein protein-1, researchers from the Peking University in China obtained GM tomato lines with increased zinc content and anti-oxidant activity.

MT-1 has a selective binding capacity for zinc. The levels of zinc were found to be much higher in leaves of the transformants compared to those of the non-transgenic control.  In addition, the transgenic lines obtained exhibited increased superoxide dismutase activity. Superoxide dismutase is the enzyme responsible for removing the harmful oxygen radicals that can cause cell damage. Among antioxidant enzymes, the level of SOD activity is relevant in maintaining the overall defense system of plants subjected to oxidative stress. Transgenic MT tomato may potentially be used as an antioxidant and for zinc supplementation.

Read the paper published by the Journal of Agricultural Food and Chemistry at http://pubs.acs.org/cgi-bin/asap.cgi/jafcau/asap/pdf/jf0709707.pdf or http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/asap/abs/jf0709707.html