Papaver somniferum (poppy) is a traditional ingredient in Central and Eastern European cuisine and an important oilseed crop of the region. Since the main threat to stable poppy yield is pathogen infection, a detailed understanding of its defence mechanism is essential. The first robust layer of plant immunity, which plays a crucial role in combating pathogens, is pattern-triggered immunity (PTI). Here, we provide the first comprehensive insights into PTI in poppy. We selected four poppy varieties used in the food industry and investigated their response to various previously described peptide elicitors. Among all tested peptides, flg22 induced the most robust reactive oxygen species (ROS) burst, as well as triggering putative mitogen-activated protein kinase phosphorylation and seedling growth inhibition in all selected cultivars. We identified PsWRKY22 and PsPR2 as candidate marker genes suitable for monitoring poppy PTI responses. The tested poppy cultivars have low levels of salicylic acid. Callose accumulation was triggered by wounding but not by flg22. When studying PTI in plants, wounding is a challenge that needs to be considered, as it can obscure potential PTI responses. Our findings highlight conserved aspects of poppy immunity and the challenges of studying its PTI. The established pipeline facilitates improving our understanding of poppy immunity and has the potential for widespread application in breeding and improving selection for broad-spectrum disease resistance provided by enhanced PTI.

Department of Chemistry Faculty of Science University of South Bohemia in České Budějovice Branišovská 1645 31a České Budějovice 370 05 Czech Republic

Department of Experimental Plant Biology Faculty of Science University of South Bohemia in České Budějovice Branišovská 1645 31a České Budějovice 370 05 Czech Republic

Department of Food Science Faculty of Agrobiology Food and Natural Resources Czech University of Life Sciences Prague Kamýcká 129 Suchdol Praha 6 165 00 Czech Republic

Department of Genetics and Biotechnologies Faculty of Agriculture and Technology University of South Bohemia in České Budějovice Branišovská 1645 31a České Budějovice 370 05 Czech Republic

Institute of Plant Molecular Biology Biology Centre Czech Academy of Sciences Branišovská 1160 31 České Budějovice 370 05 Czech Republic

Laboratory of Plant Biotechnologies Institute of Experimental Botany Czech Academy of Sciences Rozvojová 263 Lysolaje Praha 6 165 02 Czech Republic

OSEVA vývoj a výzkum s r o Výzkumný ústav olejnin Opava Purkyňova 10 Opava 764 01 Czech Republic

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Adero  M, Tripathi  JN, Oduor  R  et al.  Transgenic expression of Arabidopsis ELONGATION FACTOR-TU RECEPTOR (AtEFR) gene in banana enhances resistance against PubMed DOI PMC

Agu  PC, Afiukwa  CA, Orji  OU  et al.  Molecular docking as a tool for the discovery of molecular targets of nutraceuticals in diseases management. Sci Rep  2023;13:13398. 10.1038/s41598-023-40160-2 PubMed DOI PMC

Alam  M, Samad  A, Khaliq  A  et al.  Disease incidence and its management on opium poppy: a global perspective. Acta Hortic  2014;1036:123–39. 10.17660/ActaHortic.2014.1036.14 DOI

Altschul  SF, Gish  W, Miller  W  et al.  Basic local alignment search tool. J Mol Biol  1990;215:403–10. 10.1016/S0022-2836(05)80360-2 PubMed DOI

Bailey  BA, Apel-Birkhold  PC, O’Neill  NR  et al.  Evaluation of infection processes and resulting disease caused by PubMed DOI

Beaudoin  GAW, Facchini  PJ. Benzylisoquinoline alkaloid biosynthesis in opium poppy. Planta  2014;240:19–32. 10.1007/s00425-014-2056-8 PubMed DOI

Bigeard  J, Colcombet  J, Hirt  H. Signaling mechanisms in pattern-triggered immunity (PTI). Mol Plant  2015;8:521–39. 10.1016/j.molp.2014.12.022 PubMed DOI

Bjornson  M, Pimprikar  P, Nürnberger  T  et al.  The transcriptional landscape of PubMed DOI PMC

Boschi  F, Schvartzman  C, Murchio  S  et al.  Enhanced bacterial wilt resistance in potato through expression of PubMed DOI PMC

Boutrot  F, Zipfel  C. Function, discovery, and exploitation of plant pattern recognition receptors for broad-spectrum disease resistance. Annu Rev Phytopathol  2017;55:257–86. 10.1146/annurev-phyto-080614-120106 PubMed DOI

Bradford  M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem  1976;72:248–54. 10.1016/0003-2697(76)90527-3 PubMed DOI

Chi  Y, Wang  C, Wang  M  et al.  Flg22-induced Ca PubMed DOI

Chinchilla  D, Bauer  Z, Regenass  M  et al.  The PubMed DOI PMC

Choi  HW, Klessig  DF. DAMPs, MAMPs, and NAMPs in plant innate immunity. BMC Plant Biol  2016;16:232. 10.1186/s12870-016-0921-2 PubMed DOI PMC

csu.gov.cz . 2025. https://csu.gov.cz/mak (16 October 2025, date last accessed).

Dallakyan  S, Olson  AJ. Small-molecule library screening by docking with PyRx. Methods Mol Biol  2015:243–50. 10.1007/978-1-4939-2269-7_19 PubMed DOI

Ellinger  D, Voigt  CA. Callose biosynthesis in Arabidopsis with a focus on pathogen response: what we have learned within the last decade. Ann Bot  2014;114:1349–58. 10.1093/aob/mcu120 PubMed DOI PMC

Felix  G, Duran  JD, Volko  S  et al.  Plants have a sensitive perception system for the most conserved domain of bacterial flagellin. Plant J  1999;18:265–76. 10.1046/j.1365-313X.1999.00265.x PubMed DOI

Frei dit Frey  N, Garcia  AV, Bigeard  J  et al.  Functional analysis of arabidopsisimmune-related MAPKs uncovers a role for MPK3 as negative regulator of inducible defences. Genome Biol  2014;15:R87. 10.1186/gb-2014-15-6-r87 PubMed DOI PMC

Garcia-Alonso  M, Novillo  C, Kostolaniova  P  et al.  The EU’s GM crop conundrum. EMBO Rep  2022;23:e54529. 10.15252/embr.202154529 PubMed DOI PMC

Geitmann  A, Franklin-Tong  VE, Emons  AC. The self-incompatibility response in PubMed DOI

Gimenez-Ibanez  S, Zamarreño  AM, García-Mina  JM  et al.  An evolutionarily ancient immune system governs the interactions between PubMed DOI

Gingeras  TR, Myers  PA, Olson  JA  et al.  A new specific endonuclease present in PubMed DOI

Gómez-Gómez  L, Felix  G, Boller  T. A single locus determines sensitivity to bacterial flagellin in PubMed DOI

Guo  L, Winzer  T, Yang  X  et al.  The opium poppy genome and morphinan production. Science  2018;362:343–7. 10.1126/science.aat4096 PubMed DOI

Hao  L, Zhao  Y, Jin  D  et al.  Salicylic acid-altering Arabidopsis mutants response to salt stress. Plant Soil  2012;354:81–95. 10.1007/s11104-011-1046-x DOI

He  Z, Webster  S, He  SY. Growth–defense trade-offs in plants. Curr Biol  2022;32:R634–9. 10.1016/j.cub.2022.04.070 PubMed DOI

Hou  S, Liu  Z, Shen  H  et al.  Damage-associated molecular pattern-triggered immunity in plants. Front Plant Sci  2019;10:646. 10.3389/fpls.2019.00646 PubMed DOI PMC

https://grinczech.vurv.cz . https://grinczech.carc.cz/gringlobal/search.aspx (16 October 2025, date last accessed).

Huffaker  A, Pearce  G, Ryan  CA. An endogenous peptide signal in PubMed DOI PMC

Hulme  EC, Trevethick  MA. Ligand binding assays at equilibrium: validation and interpretation. Br J Pharmacol  2010;161:1219–37. 10.1111/j.1476-5381.2009.00604.x PubMed DOI PMC

Janda  M, Lamparová  L, Zubíková  A  et al.  Temporary heat stress suppresses PAMP-triggered immunity and resistance to bacteria in PubMed DOI PMC

Janda  M, Rybak  K, Krassini  L  et al.  Biophysical and proteomic analyses of PubMed DOI PMC

Jetter  R, Riederer  M. Cuticular waxes from the leaves and fruit capsules of eight DOI

Jones  JDG, Dangl  JL. The plant immune system. Nature  2006;444:323–9. 10.1038/nature05286 PubMed DOI

Jumper  J, Evans  R, Pritzel  A  et al.  Highly accurate protein structure prediction with AlphaFold. Nature  2021;596:583–9. 10.1038/s41586-021-03819-2 PubMed DOI PMC

Kalachova  T, Janda  M, Šašek  V  et al.  Identification of salicylic acid-independent responses in an Arabidopsis phosphatidylinositol 4-kinase beta double mutant. Ann Bot  2020;125:775–84. 10.1093/aob/mcz112 PubMed DOI PMC

Kubásek  J, Kalistová  T, Janová  J  et al. PubMed DOI

Kulich  I, Vladimirtsev  D, Randuch  M  et al. Calcium-triggered apoplastic ROS bursts balance gravity and mechanical signals to navigate soil. bioRxiv, 10.1101/2025.01.07.631646, 13 January 2025, preprint: not peer reviewed. DOI

Kunze  G, Zipfel  C, Robatzek  S  et al.  The N terminus of bacterial elongation factor Tu elicits innate immunity in Arabidopsis plants. Plant Cell  2004;16:3496–507. 10.1105/tpc.104.026765 PubMed DOI PMC

Lacombe  S, Rougon-Cardoso  A, Sherwood  E  et al.  Interfamily transfer of a plant pattern-recognition receptor confers broad-spectrum bacterial resistance. Nat Biotechnol  2010;28:365–9. 10.1038/nbt.1613 PubMed DOI

Landa  BB, Montes-Borrego  M, Muñoz-Ledesma  FJ  et al.  Phylogenetic analysis of downy mildew pathogens of opium poppy and PCR-based in planta and seed detection of PubMed DOI

Lee  SB, Suh  MC. Advances in the understanding of cuticular waxes in PubMed DOI

Leontovyčová  H, Kalachova  T, Trdá  L  et al.  Actin depolymerization is able to increase plant resistance against pathogens via activation of salicylic acid signalling pathway. Sci Rep  2019;9:10397. 10.1038/s41598-019-46465-5 PubMed DOI PMC

Liu  X, Ma  Z, Tran  TM  et al.  Balanced callose and cellulose biosynthesis in Arabidopsis quorum-sensing signaling and pattern-triggered immunity. Plant Physiol  2023;194:137–52. 10.1093/plphys/kiad473 PubMed DOI PMC

Livak  KJ, Schmittgen  TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method. Methods  2001;25:402–8. 10.1006/meth.2001.1262 PubMed DOI

Lloyd  SR, Schoonbeek  H, Trick  M  et al.  Methods to study PAMP-triggered immunity in PubMed DOI

Lu  F, Wang  H, Wang  S  et al.  Enhancement of innate immune system in monocot rice by transferring the dicotyledonous elongation factor Tu receptor EFR. J Integr Plant Biol  2015;57:641–52. 10.1111/jipb.12306 PubMed DOI

Mason  KN, Ekanayake  G, Heese  A. Staining and automated image quantification of callose in Arabidopsis cotyledons and leaves. Methods Cell Biol  2020;160:181–99. 10.1016/bs.mcb.2020.05.005 PubMed DOI

Melo  D, Álvarez-Ortí  M, Nunes  MA  et al.  Nutritional and chemical characterization of poppy seeds, cold-pressed oil, and cake: poppy cake as a high-fibre and high-protein ingredient for novel food production. Foods  2022;11:3027. 10.3390/foods11193027 PubMed DOI PMC

Mitre  LK, Teixeira-Silva  NS, Rybak  K  et al.  The PubMed DOI PMC

Moroz  N, Tanaka  K. FlgII-28 is a major flagellin-derived defense elicitor in potato. Mol Plant Microbe Interact  2020;33:247–55. 10.1094/MPMI-06-19-0164-R PubMed DOI

Morris  GM, Huey  R, Lindstrom  W  et al.  AutoDock4 and AutoDockTools4: automated docking with selective receptor flexibility. J Comput Chem  2009;30:2785–91. 10.1002/jcc.21256 PubMed DOI PMC

museum.dea.gov . https://museum.dea.gov/exhibits/online-exhibits/cannabis-coca-and-poppy-natures-addictive-plants/opium-poppy (16 October 2025, date last accessed).

Neugschwandtner  RW, Dobos  G, Wagentristl  H  et al.  Yield and yield components of winter poppy ( DOI

Nguyen  HP, Chakravarthy  S, Velásquez  AC  et al.  Methods to study PAMP-triggered immunity using tomato and PubMed DOI

Nietzschmann  L, Gorzolka  K, Smolka  U  et al.  Early Pep-13-induced immune responses are SERK3A/B-dependent in potato. Sci Rep  2019;9:18380. 10.1038/s41598-019-54944-y PubMed DOI PMC

O’Boyle  NM, Banck  M, James  CA  et al.  Open Babel: an open chemical toolbox. J Cheminform  2011;3:33. 10.1186/1758-2946-3-33 PubMed DOI PMC

O’Neill  NR, Jennings  JC, Bailey  BA  et al. PubMed DOI

Ortiz-Morea  FA, Savatin  DV, Dejonghe  W  et al.  Danger-associated peptide signaling in PubMed DOI PMC

Patzak  J, Dobrev  PI, Motyka  V. Endogenous phytohormone levels in dwarf and normal hop ( DOI

Petrek  J, Havel  L, Petrlova  J  et al.  Analysis of salicylic acid in willow barks and branches by an electrochemical method. Russ J Plant Physiol  2007;54:553–8. 10.1134/S1021443707040188 DOI

Piazza  S, Campa  M, Pompili  V  et al.  The Arabidopsis pattern recognition receptor EFR enhances fire blight resistance in apple. Hortic Res  2021;8:204. 10.1038/s41438-021-00639-3 PubMed DOI PMC

Pluhařová  K, Leontovyčová  H, Stoudková  V  et al.  “Salicylic acid mutant collection” as a tool to explore the role of salicylic acid in regulation of plant growth under a changing environment. Int J Mol Sci  2019;20:6365. 10.3390/ijms20246365 PubMed DOI PMC

Prochazka  P, Smutka  L. Czech republic as an important producer of poppy seed. AGRIS on-line Pap Econ Inform  2012;4:1–13. 10.22004/ag.econ.131361 DOI

Ray  T, Pandey  A, Pandey  SS  et al.  Molecular insights into enhanced resistance of PubMed DOI

Schindelin  J, Arganda-Carreras  I, Frise  E  et al.  Fiji: an open-source platform for biological-image analysis. Nat Methods  2012;9:676–82. 10.1038/nmeth.2019 PubMed DOI PMC

Schoonbeek  H, Wang  H, Stefanato  FL  et al.  Arabidopsis EF-Tu receptor enhances bacterial disease resistance in transgenic wheat. New Phytol  2015;206:606–13. 10.1111/nph.13356 PubMed DOI

Schwessinger  B, Bahar  O, Thomas  N  et al.  Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses. PLoS Pathog  2015;11:e1004809. 10.1371/journal.ppat.1004809 PubMed DOI PMC

Sehnal  D, Bittrich  S, Deshpande  M  et al.  Mol* Viewer: modern web app for 3D visualization and analysis of large biomolecular structures. Nucleic Acids Res  2021;49:W431–7. 10.1093/nar/gkab314 PubMed DOI PMC

Singh  A, Menéndez-Perdomo  IM, Facchini  PJ. Benzylisoquinoline alkaloid biosynthesis in opium poppy: an update. Phytochem Rev  2019;18:1457–82. 10.1007/s11101-019-09644-w DOI

Skottke  KR, Yoon  GM, Kieber  JJ  et al.  Protein phosphatase 2A controls ethylene biosynthesis by differentially regulating the turnover of ACC synthase isoforms. PLoS Genet  2011;7:e1001370. 10.1371/journal.pgen.1001370 PubMed DOI PMC

Smith  JM, Heese  A. Rapid bioassay to measure early reactive oxygen species production in Arabidopsis leave tissue in response to living PubMed DOI PMC

Spassov  DS. Binding affinity determination in drug design: insights from lock and key, induced fit, conformational selection, and inhibitor trapping models. Int J Mol Sci  2024;25:7124. 10.3390/ijms25137124 PubMed DOI PMC

Sun  Y, Li  L, Macho  AP  et al.  Structural basis for flg22-induced activation of the PubMed DOI

Takai  R, Isogai  A, Takayama  S  et al.  Analysis of flagellin perception mediated by flg22 receptor OsFLS2 in rice. Mol Plant Microbe Interact  2008;21:1635–42. 10.1094/MPMI-21-12-1635 PubMed DOI

Tamura  K, Stecher  G, Kumar  S. MEGA11: molecular evolutionary genetics analysis version 11. Mol Biol Evol  2021;38:3022–7. 10.1093/molbev/msab120 PubMed DOI PMC

Tanaka  K, Heil  M. Damage-associated molecular patterns (DAMPs) in plant innate immunity: applying the danger model and evolutionary perspectives. Annu Rev Phytopathol  2021;59:53–75. 10.1146/annurev-phyto-082718-100146 PubMed DOI

Tee  EE, Johnston  MG, Papp  D  et al.  A PDLP-NHL3 complex integrates plasmodesmal immune signaling cascades. Proc Natl Acad Sci U S A  2023;120:e2216397120. 10.1073/pnas.2216397120 PubMed DOI PMC

Tena  G. Flagellin unmasked. Nat Plants  2019;5:452–452. 10.1038/s41477-019-0432-x PubMed DOI

Thangavel  T, Jones  S, Scott  JB  et al.  Detection of two PubMed DOI

Thangavel  T, Scott  J, Jones  S  et al.  Effect of physio-chemical seed treatments on opium poppy downy mildews caused by PubMed DOI PMC

Tian  H, Wu  Z, Chen  S  et al.  Activation of TIR signalling boosts pattern-triggered immunity. Nature  2021;598:500–3. 10.1038/s41586-021-03987-1 PubMed DOI

Trinh  J, Li  T, Franco  JY  et al.  Variation in microbial feature perception in the Rutaceae family with immune receptor conservation in citrus. Plant Physiol  2023;193:689–707.. 10.1093/plphys/kiad263 PubMed DOI PMC

Trinh  J, Tran  M, Coaker  G. The perception and evolution of flagellin, cold shock protein and elongation factor Tu from vector-borne bacterial plant pathogens. Mol Plant Pathol  2024;25:e70019. 10.1111/mpp.70019 PubMed DOI PMC

Tsuda  K, Sato  M, Glazebrook  J  et al.  Interplay between MAMP-triggered and SA-mediated defense responses. Plant J  2008;53:763–75. 10.1111/j.1365-313X.2007.03369.x PubMed DOI

Wierzba  MP, Tax  FE. An allelic series of PubMed DOI PMC

Wilkins  KA, Bosch  M, Haque  T  et al.  Self-incompatibility-induced programmed cell death in field poppy pollen involves dramatic acidification of the incompatible pollen tube cytosol. Plant Physiol  2015;167:766–79. 10.1104/pp.114.252742 PubMed DOI PMC

www.efsa.europa.eu . 2025. https://www.efsa.europa.eu/en/press/news/180516 (16 October 2025, date last accessed).

www.fao.org . https://www.fao.org/plant-production-protection/about/en (16 October 2025, date last accessed).

Yi  SY, Min  SR, Kwon  S-Y. NPR1 is instrumental in priming for the enhanced flg22-induced MPK3 and MPK6 activation. Plant Pathol J  2015;31:192–4. 10.5423/PPJ.NT.10.2014.0112 PubMed DOI PMC

Zahid  A, Jaber  R, Laggoun  F  et al.  Holaphyllamine, a steroid, is able to induce defense responses in PubMed DOI

Zipfel  C, Robatzek  S, Navarro  L  et al.  Bacterial disease resistance in Arabidopsis through flagellin perception. Nature  2004;428:764–7. 10.1038/nature02485 PubMed DOI

Zou  Y, Wang  S, Zhou  Y  et al.  Transcriptional regulation of the immune receptor FLS2 controls the ontogeny of plant innate immunity. Plant Cell  2018;30:2779–94. 10.1105/tpc.18.00297 PubMed DOI PMC