On plant defense signaling networks and early land plant evolution

Commun Integr Biol. 2018 Aug 9;11(3):1-14. doi: 10.1080/19420889.2018.1486168. eCollection 2018.


All land plants must cope with phytopathogens. Algae face pathogens, too, and it is reasonable to assume that some of the strategies for dealing with pathogens evolved prior to the origin of embryophytes - plant terrestrialization simply changed the nature of the plant-pathogen interactions. Here we highlight that many potential components of the angiosperm defense toolkit are i) found in streptophyte algae and non-flowering embryophytes and ii) might be used in non-flowering plant defense as inferred from published experimental data. Nonetheless, the common signaling networks governing these defense responses appear to have become more intricate during embryophyte evolution. This includes the evolution of the antagonistic signaling pathways of jasmonic and salicylic acid, multiple independent expansions of resistance genes, and the evolution of resistance gene-regulating microRNAs. Future comparative studies will illuminate which modules of the streptophyte defense signaling network constitute the core and which constitute lineage- and/or environment-specific (peripheral) signaling circuits.

Keywords: Plant evolution; charophytes; molecular plant–microbe interaction; phytopathology; plant defense; streptophyte algae.

Publication types

  • Review

Grants and funding

This work was supported by the Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada [Discovery grant RGPIN/05754-2015]; Deutsche Forschungsgemeinschaft [VR 132/1-1]; Deutsche Forschungsgemeinschaft [Research Training Group GRK1525]; Killam Trusts [Izaak Walton Killam Postdoctoral Fellowship].