Could plant-defence priming be a platform for a new green revolution?

A plant that has been "warned" by a microbe, an insect or a chemical can respond faster and harder when it is attacked later, often at little cost to its growth. Could this priming of defences protect crops at scale and reduce the use of pesticides?

Question

Could defence priming, a state in which a plant's induced defences are mobilised faster and more strongly once a pest, pathogen or abiotic stress arrives, become the basis of a new green revolution, giving broad and durable crop protection in farmers' fields with fewer agrochemicals and little cost to yield?

Background

It is one of eleven questions that the panels behind the 2023 list of 100 important questions facing plant science chose to represent the areas with most submissions, here sustainability, as timely, globally relevant, innovative and potentially tractable in a research career [1].

What is known

• Priming can be triggered by pathogens, beneficial microbes, arthropods, chemicals and abiotic cues; primed plants mount a faster and/or stronger defence when challenged, and priming can last through the life cycle and even pass to the next generation [2].
• In Arabidopsis, priming with low doses of β-aminobutyric acid caused only minor growth reductions and no loss of seed production, unlike directly induced defence; under disease, primed plants were fitter than untreated ones [3].
• In crops, most resistance-inducing agents reduce disease by 20–85% but rarely completely, and their field performance depends on environment, genotype, crop nutrition and prior induction [4].
• Priming effects depend on both the agent and the attacker, and are usually larger against bacterial pathogens than against herbivores [5]. Across studies, seed defence priming raised resistance in crops and cereals without a fitness penalty, with natural compounds and biological isolates outperforming synthetic chemicals [6].

What would count as progress

No single result settles a question like this; contributions like these would move it forward:

• Multi-site, multi-season field trials of priming agents in major crops, reporting yield, disease and pesticide use against standard practice, with the data released openly.
• A meta-analysis of field studies estimating the yield benefit and cost of priming by agent, crop and type of attacker.
• Molecular markers (for example transcript or chromatin signatures) that predict whether a priming treatment will work in a given field, validated before the season starts.

References

1. Armstrong, E. M. et al. (2023). One hundred important questions facing plant science: an international perspective. New Phytologist 238(2), 470–481.
2. Mauch-Mani, B. et al. (2017). Defense priming: an adaptive part of induced resistance. Annual Review of Plant Biology 68, 485–512.
3. van Hulten, M. et al. (2006). Costs and benefits of priming for defense in Arabidopsis. Proceedings of the National Academy of Sciences 103(14), 5602–5607.
4. Walters, D. R. et al. (2013). Controlling crop diseases using induced resistance: challenges for the future. Journal of Experimental Botany 64(5), 1263–1280.
5. Westman, S. M. et al. (2019). Defence priming in Arabidopsis – a meta-analysis. Scientific Reports 9, 13309.
6. Talavera-Mateo, L. et al. (2023). A comprehensive meta-analysis reveals the key variables and scope of seed defense priming. Frontiers in Plant Science 14, 1208449.

Source

Imported from One hundred important questions facing plant science, question 5, curated by Armstrong et al. Listed as open in the source (2023) and still an active research question as of 2026-10-20. The statement above is written in our own words; see the source for the original wording, history and discussion.