The particular scientific discoveries on which current gene technology is based were made in the 1970s.
In June 1973, a conference was held to discuss safety issues. The US National Institutes of Health and of Medicine were asked to appoint a committee to study the matter. Another meeting in 1975 concluded that genetic modification work should continue with appropriate safeguards in the form of physical and biological containment procedures.
It was from these beginnings that the current regulatory frameworks and procedures were developed, first in the US (where applications of the technology began) and then, along roughly similar lines, in other developed countries.
The first GM plants began to be developed in the early 1980s.
B. Martineau (2001). First fruit - the creation of Flavr Savr™ tomato and the birth of biotech food. McGraw-Hill
B. Lewin (2000). Genes VII. Oxford University Press
B. Alberts et. al. (2002). Molecular Biology of the Cell. Garland Science
or any other good textbook on molecular genetics