Cold can damage pollen, delay anther opening, interfere with pollen transfer and reduce fertilization, while heat can also disturb reproductive development and fruit set. The modified plants were able to initiate fruit development without fertilization, a phenomenon known as parthenocarpy. Early in the growing season, the gene-edited plants produced more than 18 times as many fruits as regular tomato plants. Professor Ori said the findings show how tomato plants use a carefully balanced genetic system to coordinate flower development, pollen release and the beginning of fruit growth. Even so, the study provides a detailed molecular explanation for why certain tomato plants can continue setting fruit when cold suppresses ordinary fertilization.