3rd Edition Of Plant Science and Molecular Biology World Conference 2026

Abstract

The induction of systemic acquired resistance (SAR) has long been regarded as a promising strategy for reducing reliance on conventional chemical plant protection products. In the context of increasingly restrictive pesticide regulations and growing concerns related to food safety and environmental impact, SAR inducers are frequently proposed as tools to enhance crop protection by activating endogenous plant defense mechanisms rather than relying solely on direct biocidal activity. Salicylic acid (SA)-dependent signaling plays a central role in this process and represents one of the best-characterized pathways of plant innate immunity.

Despite extensive experimental evidence demonstrating the effectiveness of SAR induction, its implementation in open-field agriculture has remained limited. One of the key constraints is the well-documented immunity–growth trade-off, whereby activation of defense responses may divert metabolic resources away from growth and yield formation. This trade-off, together with narrow dose–response windows, variable field performance, and occasional phytotoxic effects, has reduced the practical attractiveness of classical SAR inducers when used as stand-alone crop protection tools.

This contribution discusses SAR primarily in the context of plant protection and pesticide reduction, reviewing selected literature-reported SAR inducers, including synthetic compounds, natural elicitors, and fungicides exhibiting resistance-inducing side effects. Particular attention is given to examples where SAR induction has enabled a reduction in fungicide intensity rather than complete replacement, highlighting the importance of integration within integrated pest management (IPM) frameworks. Such examples illustrate that SAR-based strategies are most effective when used to support, rather than substitute, conventional plant protection programs.

In parallel, the presentation introduces designable salicylates as a distinct and complementary approach. Unlike classical SAR inducers, these compounds are discussed not only as resistance activators, but as plant stimulants capable of modulating physiological performance under stress conditions. By tailoring physicochemical properties such as solubility, bioavailability, and plant compatibility, designable salicylates aim to minimize defense-related fitness costs while enhancing photosynthetic efficiency, biomass accumulation, and yield stability. In this context, their role is not to trigger strong immune responses, but rather to fine-tune plant metabolism and stress responsiveness.

Experimental data from greenhouse and field studies indicate that, when applied at optimized doses and in combination with reduced fungicide programs, designable salicylates can support plant performance without exacerbating the immunity–growth trade-off. The contribution concludes by emphasizing that future crop protection strategies should distinguish clearly between defense induction and growth stimulation, integrating SAR inducers as protective tools and plant stimulants as productivity-enhancing components within sustainable agricultural systems.

The “Searching for new chemical compounds inducing resistance of apple to diseases and determination of the molecular mechanism of their action” project is carried out within the Sonata (UMO-2022/47/D/NZ9/02327) programme of the National Science Center, Poland.