GMWatch, 16 February 2016
Unintended effects of GM process burst hype bubble
A new study reports unintended effects in GM golden rice, which is engineered to produce precursors of vitamin A called carotenoids. But crossing the GM rice with the Indian variety Swarna, a step necessary for commercialization, led to a nasty surprise. The resulting plants were stunted, showed extensive abnormalities in their growth, and had reduced grain yield, as compared with the non-GM Swarna variety.
The researchers identified several reasons for the unexpected effects – the new gene constructs interfered with the plant’s own gene for producing growth hormones, and the additional gene constructs were not, as intended, active solely in the kernels, but also in the leaves. This led to a substantial reduction in the content of chlorophyll that is essential for vital functions in the plants.
These unintended effects were not detected in previous investigations, and it was assumed that the genetically engineered plants used in these trials would show genetic stability. In fact, these detrimental genomic effects remained undetected until the transgenic plants were crossed with the variety called Swarna, which is grown widely in India.
London-based molecular geneticist Dr Michael Antoniou commented on the new findings: “I have always asserted that the GM transformation process as used in the development of GMO crops selects for the insertion of the GM gene into active regions of the genome (areas where plant host genes are switched on and functioning). This bias in the GM gene insertion into active regions therefore maximises the possibility of disrupting the function of one or more host genes, with potentially adverse effects such as poor crop performance or even toxicity.