It’s common wisdom that one rotten apple in a barrel spoils all the other apples, and that an apple ripens a green banana if they are put together in a paper bag. Ways to ripen, or spoil, fruit have been known for thousands of years — as the Bible can attest — but now the genes underlying these phenomena of nature have been revealed. Scientists have now traced the thousands of genes in a plant that are activated once ethylene, a gas that acts as a plant growth hormone, is released.