Elicitor action: from recognition to response

The action of elicitors starts with the molecule's recognition by receptors on the cell surface. These receptors function as “warning sensors” and then activate stress signaling pathways.

This process proceeds in three main structures:

• Perception: recognition of the elicitor
• Signal cascade: activation of internal messengers
• Response: defense and adaptation

Elicitors and stress signaling pathways

Elicitors are directly linked to stress signaling pathways. Upon recognition, a cascade of signals such as calcium fluxes, phosphorylation reactions, and controlled ROS peaks occurs.

These signals lead to the activation of gene expression and metabolic pathways that prepare the plant for stress.

ROS as part of elicitor action

An early response to elicitors is often a transient increase in reactive oxygen species (ROS). This ROS peak serves as a signal, not as a damage factor. A good antioxidant network ensures that ROS are quickly neutralized once the signaling function is fulfilled.

Thus, elicitors form a link between ROS neutralization and defense activation.

Elicitors and plant priming

One of the main effects of elicitors is the activation of plant priming. This means that the plant is brought into an elevated state of readiness, enabling quicker and more efficient response to subsequent stress.

Primed plants respond faster to drought, salt stress, or pathogens, with less energy loss and reduced growth inhibition.

Biotic stress: resilience against pathogens

Elicitors play a major role in enhancing plant resilience against biotic stress factors such as fungi and bacteria. Activation of natural defense reactions leads to a strengthened cell wall, production of phytoalexins, and increased resistance.

Abiotic stress: broader stress adaptation

Although elicitors are often associated with pathogen defense, they also contribute to abiotic stress adaptation. By preemptively activating stress pathways, the plant can better handle drought, heat, and nutrient imbalances.

Examples of elicitor raw materials

Within biostimulant raw materials, various elicitors are present, often derived from natural matrices.

Chitosan

Chitosan is recognized by plants as a fungal-like signal and activates broad defense and priming pathways.

Polysaccharides from seaweed extracts

Complex polysaccharides from, for example, Ascophyllum nodosum function as elicitors supporting stress adaptation.

Microbial metabolites

Metabolites from beneficial microorganisms drive rhizosphere communication and enhance resilience through systemic signaling.

Phenolic compounds

Polyphenols support antioxidant protection and contribute to controlled defense responses.

Elicitors in an integral biostimulation strategy

Within an integral biostimulation strategy, elicitors are not seen as standalone additions, but as functional links connecting stress signals, resilience, and metabolic stability.

Elicitors are often combined with osmoprotectants and chelators so that the plant not only responds but also remains physiologically stable during stress.

From stress to yield: functional value of elicitors

Uncontrolled stress leads to growth inhibition, chlorophyll breakdown, and yield loss. By deploying elicitors preventively, stress peaks are flattened and the plant recovers faster.

This results in:

• Less disease and stress pressure
• Faster recovery capacity
• Better crop uniformity
• More stable yield and quality

Overview: elicitor action in biostimulation