Herbivory-induced systemic signals are likely to be evolutionarily conserved in euphyllophytes

Area of Science:

• Plant Biology
• Ecology
• Evolutionary Biology

Background:

• Herbivory triggers systemic signaling in plants for defense against insects.
• The evolutionary origins and nature of these signals are not fully understood.
• Traditional grafting methods are limited for studying inter-species signaling, especially between monocots and dicots.

Purpose of the Study:

• To investigate the transferability and evolutionary conservation of herbivory-induced systemic signals.
• To explore the potential of using parasitic plants for inter-species signaling studies.
• To determine the role of the jasmonate pathway in systemic signal regulation.

Main Methods:

• Utilized field dodder (Cuscuta campestris) to create inter-plant connections between phylogenetically distant species (fern, monocot, dicot).
• Simulated herbivory on one plant and monitored for induced defenses in the connected plant.
• Analyzed signal transfer and defense responses across different plant groups.

Main Results:

• Herbivory-induced systemic signals were successfully transferred via dodder between monocots and dicots, and even between ferns and dicots.
• Recipient plants exhibited elevated defenses after signal transfer, confirming signal efficacy.
• The jasmonate pathway was implicated as an ancient regulator of these systemic signals.

Conclusions:

• Herbivory-induced systemic signals are likely evolutionarily conserved among vascular plants.
• Dodder parasitism provides a viable method for studying long-distance, inter-species plant communication.
• The jasmonate pathway plays a crucial role in the ancient regulation of plant defense signaling.