There are many pros for it but you gotta watch out for the cons i did a project last semester in my biotech class.
Food that can deliver vaccines - bananas that produce hepatitis B vaccine
More nutritious foods - rice with increased iron and vitamins
Faster growing fish, fruit and nut trees
Plants producing new plastics on it
One good one is Golden rice it has beta carotene in it to help produce vitamin A in third world countries because rice is cheap and vitamin A deficiency is one of the main problems in 3rd world countries. Some good things to search on google is purple tomatoes, BT corn, Bt-potatoes, Bt-corn, Bt-sweet corn, Roundup Ready soybeans, Roundup Ready Corn, which BT stands for Bacillus thuringiensis. and these foods. Does that help?But do some searchin on purple tomatoes