What has been shown to reduce damage to plants by ozone?

Ethylenediura (EDU) has been shown to effectively reduce damage to plants caused by ozone exposure. This compound acts as a protective agent that helps plants cope with oxidative stress, which is a significant factor when plants are subjected to ozone. EDU works by enhancing the plant's ability to detoxify reactive oxygen species (ROS) that are generated as a result of ozone exposure. This detoxification process minimizes chlorotic and necrotic (dead) tissue that can occur when plants are under stress from ozone, thereby maintaining overall plant health and yield.

In contrast, the other substances listed do not possess the specific protective qualities against ozone damage. Abscisic acid is primarily involved in plant responses to stress and moisture regulation but does not directly combat ozone toxicity. Gibberellin is mainly related to promoting growth and developmental processes rather than acting as a stress protectant in relation to ozone. Cytokinin supports cell division and growth but similarly does not have a direct role in mitigating ozone effects on plants. Thus, EDU stands out as the effective choice in providing protection against ozone-induced plant damage.