RT Journal Article SR Electronic T1 Laminarin-triggered defence responses are geographically dependent for natural populations of Solanum chilense JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.06.25.449942 DO 10.1101/2021.06.25.449942 A1 Kahlon, Parvinderdeep S. A1 Förner, Andrea A1 Muser, Michael A1 Oubounyt, Mhaned A1 Gigl, Michael A1 Hammerl, Richard A1 Baumbach, Jan A1 Hückelhoven, Ralph A1 Dawid, Corinna A1 Stam, Remco YR 2022 UL http://biorxiv.org/content/early/2022/12/06/2021.06.25.449942.abstract AB Natural plant populations are polymorphic and show intraspecific variation in resistance properties against pathogens. The activation of the underlying defence responses can depend on variation in perception of pathogen-associated molecular patterns or elicitors. To dissect such variation, we evaluated the responses induced by laminarin, (a glucan, representing an elicitor from oomycetes) in the wild tomato species Solanum chilense and correlated this to observed infection frequencies of Phytophthora infestans.We measured reactive oxygen species burst and levels of diverse phytohormones upon elicitation in 83 plants originating from nine populations. We found high diversity in basal and elicitor-induced levels of each component. Further we generated linear models to explain the observed infection frequency of P. infestans. The effect of individual components differed dependent on the geographical origin of the plants. We found that the resistance in the southern coastal region, but not in the other regions is directly correlated to ethylene responses and confirmed this positive correlation using ethylene inhibition assays.Our findings reveal high diversity in the strength of defence responses within a species and the involvement of different components with a quantitatively different contribution of individual components to resistance in geographically separated populations of a wild plant species.Highlight Large-scale screenings reveal geographically distinct intraspecific differences in the dominant physiological pathogen defence responses upon glucan elicitor treatment in a wild tomato species.Competing Interest StatementThe authors have declared no competing interest.