{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T17:52:03Z","timestamp":1791568323559,"version":"4.3.4"},"reference-count":55,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T00:00:00Z","timestamp":1761004800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Cyclic lipopeptides (CLPs), produced by beneficial rhizobacteria such as Bacillus and Pseudomonas species, are specialized metabolites retaining key functions for the plant protective activity of the producers, which shows their potential as biocontrol agents in agriculture. Beyond their strong antimicrobial properties, CLPs can act as potent elicitors of plant immunity and systemic resistance. However, the molecular mechanisms underlying these immune-modulatory effects and the role of CLPs\u2019 structural diversity remain poorly understood. Here, we demonstrate that specific structural features of surfactin-type CLPs critically influence their ability to trigger early immune responses in plants, including reactive oxygen species bursts, nitric oxide (NO) production, calcium fluxes, and systemic resistance. In Arabidopsis thaliana roots, we show that surfactin-induced NO generation requires calcium signaling. Moreover, we reveal that contrasting immune effects of CLPs may stem from the ecological lifestyles of their microbial producers, shedding light on the evolutionary basis of plant\u2013microbe interactions. Altogether, our findings underscore the importance of CLP structural variation in shaping plant defense responses and highlight the potential for structure-informed design of next-generation biosourced small molecules with broad-spectrum efficacy as plant protectants.<\/jats:p>","DOI":"10.3390\/biom15101479","type":"journal-article","created":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T14:17:35Z","timestamp":1761056255000},"page":"1479","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Surfactin Structural Variants Differentially Modulate Plant Immune Responses"],"prefix":"10.3390","volume":"15","author":[{"given":"Ning","family":"Ding","sequence":"first","affiliation":[{"name":"Microbial Processes and Interactions (MiPI) Laboratory, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Li\u00e8ge, B-5030 Gembloux, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hansong","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Plant Protection, Shandong Agricultural University, Taian 271028, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Romain","family":"Thomas","sequence":"additional","affiliation":[{"name":"Microbial Processes and Interactions (MiPI) Laboratory, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Li\u00e8ge, B-5030 Gembloux, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4651-2920","authenticated-orcid":false,"given":"Guillaume","family":"Gilliard","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Biophysics at Interfaces, TERRA Research Centre, Gembloux Agro-Bio Tech, University of Li\u00e8ge, B-5030 Gembloux, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jelena","family":"Pr\u0161i\u0107","sequence":"additional","affiliation":[{"name":"Microbial Processes and Interactions (MiPI) Laboratory, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Li\u00e8ge, B-5030 Gembloux, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc","family":"Ongena","sequence":"additional","affiliation":[{"name":"Microbial Processes and Interactions (MiPI) Laboratory, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Li\u00e8ge, B-5030 Gembloux, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Clements-Decker, T., Kode, M., Khan, S., and Khan, W. 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