Climatic changes are among the most striking phenomena of the present and future period. They are forecasted to lead to rising temperatures and ozone levels, and to an increased occurrence of extreme phenomena such as heat waves. It is therefore of utmost importance the understanding of how plants will react to such abiotic stresses and which phonotypic features are more likely to confer an increased resistance. This is especially relevant for crops such as grapevine, which is the most economically important fruit crop in Europe. In this context, the present project addresses the role of volatile isoprenoids, an important class of secondary metabolites produced by plants. It is believed that isoprenoids may have an antioxidant role in plants. For one isoprenoid, i.e. isoprene, this role has been proved but the underlying mechanism is unknown. There is still lack of knowledge for other isoprenoids. Some crops, grapevine for example, do not emit isoprene but emit other isoprenoids such as monoterpenes. The overall project objectives tackle these questions. First of all, an antioxidant mechanism for isoprene in plants is assessed. Specifically, it investigated if isoprene is oxidized within-plants, thus acting as scavenger of oxidants. Furthermore, the project aims at proving that volatile isoprenoids (likely monoterpenes) have an antioxidant role in grapevine. The present project demonstrated that monoterpenes are related to increased resistance to abiotic stress in grapevine. Therefore, it proved that the role isoprene has in other plants, is played by monoterpenes in grapevine. It also showed that the main underlying mechanism is not direct reaction of isoprenoids with oxidants.
