It went like this. Take a common saprophytic bacterium, present in food, water and soil, and remove one of its 200-odd genes. Grow the organism in pure culture, spread it on plants that are harboring the wild type, and PRESTO! the massive culture of the engineered organism will prevent frost damage. The wild type of the organism contains the missing gene, but sometimes strains occur in nature without the gene. Therefore, nothing new is being turned loose into the environment, and surely no one should be worried.
Add to this the facts that an organism with one gene missing will be weakened by the omission, that strains with the gene are now being used to make ice in snow machines at ski resorts, that a bucketful of ordinary dirt contains about 8 trillion bacteria of the same genus (Pseudomonas), and that the engineered strain has been fully tested for safety ...