The worst-case scenario sometimes portrayed is that such genes could escape into plants outside cultivation, creating super weeds (weeds resistant to herbicides) or otherwise altering a plant’s ecosystem role or relative fitness (
as shown in squash) due to toxicity, growth habits, or nutrient value, with cascading ecosystem effects and potential agricultural problems.
...
If the ["Terminator"] gene enters a population of an endangered species, it would likely increase extinction risk. This example in particular stresses that a single GM trait can have varied effects, some of which extend beyond ecology and health, and affect the viability and sustainability of GMO and
non-GMO farmers.