Less Is More: A Mutation in the Chemical Defense Pathway of Erysimum cheiranthoides (Brassicaceae) Reduces Total Cardenolide Abundance but Increases Resistance to Insect Herbivores
| Autor: | Georg Jander, Tobias Zuest, Amy P. Hastings, Anurag Agrawal, Mahdieh Mirzaei |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0303 health sciences biology Brassicaceae biology.organism_classification 01 natural sciences 03 medical and health sciences chemistry.chemical_compound Wallflower Digitoxigenin Cabbage looper chemistry Botany Cardenolide Chemical defense Myzus persicae Erysimum cheiranthoides 030304 developmental biology 010606 plant biology & botany |
| DOI: | 10.1101/2020.05.01.072850 |
| Popis: | Many plants produce structurally related defensive metabolites with the same target sites in insect herbivores. Two possible drivers of this chemical diversity are: (i) interacting effects of structurally related compounds increase resistance against individual herbivores, and (ii) variants of the same chemical structures differentially affect diverse herbivore species or feeding guilds.Erysimum cheiranthoidesL (Brassicaceae; wormseed wallflower) produces abundant and diverse cardenolide toxins, which are derived from digitoxigenin, cannogenol, and strophanthidin, all of which inhibit Na+/K+-ATPases in animal cells. Here we describe anE. cheiranthoidesmutant with 66% lower cardenolide content, resulting from greatly decreased cannogenol- and strophanthidin-derived cardenolides, partially compensated for by increases in digitoxigenin-derived cardenolides. This compositional change created a more even cardenolide distribution, decreased the average cardenolide polarity, but did not impact glucosinolates, a different class of chemical defenses. Growth of generalist herbivores from two feeding guilds,Myzus persicaeSulzer (Hemiptera: Aphididae; green peach aphid) andTrichoplusia niHübner (Lepidoptera: Noctuidae; cabbage looper), was decreased on the mutant line compared to wildtype. Both herbivores accumulated cardenolides in proportion to plant content, withT. niaccumulating higher total concentrations thanM. persicae.Helveticoside, an abundant cardenolide inE. cheiranthoides, was absent inM. persicae, suggesting that this compound is not present in the phloem. Our results support the hypothesis that cardenolide diversity protects plants against different herbivores, with digitoxigenin-derived compounds providing better protection against insects likeM. persicaeandT. ni, whereas cannogenol and strophanthidin provide better protection against other herbivores ofE. cheiranthoides.FundingThis research was funded by US National Science Foundation awards 1907491 to AAA and 1645256 to GJ and AAA, Swiss National Science Foundation grant PZ00P3-161472 to TZ, and a Triad Foundation grant to GJ. |
| Databáze: | OpenAIRE |
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