Elicitor-Induced Transgenerational Priming of Defense Responses in Arabidopsis thaliana

Plant diseases cause crop losses and compromise food safety due to fungal contamination and toxins. Crop protection is currently based on genetic resistances, which are not always available and can be overcome by pathogens, or on pesticides that can pose environmental and health issues. These problems might be overcome by novel strategies that aim at promoting the natural plant defense mechanisms. The plant immune system is based on the recognition of elicitors, molecules present in pathogenic microorganisms (Pathogen-Associated Molecular Patterns, PAMPs) or released by the host in response to attack (Damage-Associated Molecular Patterns, DAMPs). Foliar treatments with elicitors often lead to an increased resistance against microbial pathogens. For instance, Arabidopsis thaliana plants sprayed with flg22, a peptide derived from bacterial flagellin, show increased resistance to the fungal pathogen Botrytis cinerea if treated 24 h before inoculation. We show here that elicitor-induced resistance (EIR) lasts for at least one week and can be transmitted to the progeny of the treated plants. The involvement of known defense-related pathways in transgenerational EIR will be discussed. Notably, EIR does not affect plant growth and seed production, suggesting that transgenerational priming is a viable and cost-effective solution for crop protection.