Plant Resistance Inducers against Pathogens in Solanaceae Species-From Molecular Mechanisms to Field Application

This review provides a current summary of plant resistance inducers (PRIs) that have been successfully used in the Solanaceae plant family to protect against pathogens by activating the plant's own defence. Solanaceous species include many important crops such as potato and tomato. We also present findings regarding the molecular processes after application of PRIs, even if the number of such studies still remains limited in this plant family. In general, there is a lack of patterns regarding the efficiency of induced resistance (IR) both between and within solanaceous species. In many cases, a hypersensitivity-like reaction needs to form in order for the PRI to be efficient. "-Omics" studies have already given insight in the complexity of responses, and can explain some of the differences seen in efficacy of PRIs between and within species as well as towards different pathogens. Finally, examples of field applications of PRIs for solanaceous crops are presented and discussed. We predict that PRIs will play a role in future plant protection strategies in Solanaceae crops if they are combined with other means of disease control in different spatial and temporal combinations.