What is the function of ethylene in plants?

Ethylene is a gaseous plant hormone known primarily for its crucial role in the ripening of fruits. It regulates various physiological processes in plants, but its most notable function is the promotion of fruit maturation and ripening. Ethylene acts as a signaling molecule that triggers the expression of genes associated with ripening, leading to changes in texture, color, and flavor. This process is vital for ensuring that fruits reach their peak quality for dispersal and consumption, which aids in reproduction.

While other options represent important functions in plant physiology, they are not primarily associated with ethylene. For instance, hormones such as auxins and cytokinins are more directly involved in stimulating root growth. Photosynthesis enhancement is primarily achieved through chlorophyll and light availability rather than ethylene's influence. Disease resistance is often related to other hormones and plant defenses rather than the action of ethylene. Thus, promoting the ripening of fruits stands out as the distinctive and well-studied role of ethylene in plant biology.