Aldehyde perception induces specific molecular responses in Laminaria digitata and affects algal consumption by a specialist grazer

Qikun Xing (1) , Léa Cabioch (1) , Antoine Desrut (2) , Gildas Le Corguillé (3, 4) , Sylvie Rousvoal (1) , Laurence Dartevelle (1) , Elodie Rolland (1) , Yann Guitton (5, 6) , Philippe Potin (1) , Gabriel V Markov (1) , Sylvain Faugeron (7) , Catherine Leblanc (8, 1, 9)

1 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins
2 LBI - Laboratoire de Biologie Intégrative
3 FR2424 - Fédération de recherche de Roscoff
4 ABIMS - ABiMS - Informatique et bioinformatique = Analysis and Bioinformatics for Marine Science
5 LABERCA - Laboratoire d'étude des Résidus et Contaminants dans les Aliments
6 MELISA - Plateforme Metabolomics, Lipidomics and Steroidomics Analysis
7 Centro de conservacion marina and CeBiB
8 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins
9 Végétaux marins et biomolécules

SUMMARY In the marine environment, distance signaling based on water‐borne cues occurs during interactions between macroalgae and herbivores. In the brown alga Laminaria digitata from North‐Atlantic Brittany, oligoalginates elicitation or grazing was shown to induce chemical and transcriptomic regulations, as well as emission of a wide range of volatile aldehydes, but their biological roles as potential defense or warning signals in response to herbivores remain unknown. In this context, bioassays using the limpet Patella pellucida and L. digitata were carried out for determining the effects of algal transient incubation with 4‐hydroxyhexenal (4‐HHE), 4‐hydroxynonenal (4‐HNE) and dodecadienal on algal consumption by grazers. Simultaneously, we have developed metabolomic and transcriptomic approaches to study algal molecular responses after treatments of L. digitata with these chemical compounds. The results indicated that, unlike the treatment of the plantlets with 4‐HNE or dodecadienal, treatment with 4‐HHE decreases algal consumption by herbivores at 100 ng.ml −1 . Moreover, we showed that algal metabolome was significantly modified according to the type of aldehydes, and more specifically the metabolite pathways linked to fatty acid degradation. RNAseq analysis further showed that 4‐HHE at 100 ng.ml −1 can activate the regulation of genes related to oxylipin signaling pathways and specific responses, compared to oligoalginates elicitation. As kelp beds constitute complex ecosystems consisting of habitat and food source for marine herbivores, the algal perception of specific aldehydes leading to targeted molecular regulations could have an important biological role on kelps/grazers interactions.

Mots clés: Brown algae; biotic interactions; defense and signaling responses; transcriptomics; metabolomics; Brown algae biotic interactions defense and signaling responses transcriptomics metabolomics

Domaines: Biologie végétale; Génomique, Transcriptomique et Protéomique [q-bio.GN]

Qikun Xing, Léa Cabioch, Antoine Desrut, Gildas Le Corguillé, Sylvie Rousvoal, et al.. Aldehyde perception induces specific molecular responses in Laminaria digitata and affects algal consumption by a specialist grazer. Plant Journal, inPress, ⟨10.1111/tpj.16450⟩. ⟨hal-04197531⟩