Wikipedia explains the word GMO in this way:
A genetically modified organism (GMO) is an organism whose genetic material has been altered using genetic engineering techniques. Organisms that have been genetically modified include micro-organisms such as bacteria and yeast, insects, plants, fish, and mammals. GMOs are the source of genetically modified foods and are also widely used in scientific research and to produce goods other than food.
USA and other countries have permitted GMO in maize and certain other agricultural products. In 2014 18 of the 28 member states were opposed to that. The Commission was in favour but proposed that the decision could be taken by the member states.
According to the voting rules the Commission could have governed against tha majority of member states.