Wound activation of jasmonate signalling: extending the squeeze cell hypothesis
Description: Jasmonates are defense regulators that accumulate rapidly in plant tissues following herbivory. Interestingly, these potent lipid mediators can be sythesized distal to wounds in unwounded leaves, but little is known about the long-distance signal pathways that activate jasmonate synthesis in undamaged tissues. For example, the specific cell types responsible for leaf-to-leaf wound signal transmission have not been identified rigorously in any plant using genetically verified signalling proteins. The proposed work aims to study several aspects of long-distance wound signalling based on the fact that certain clade 3 GLUTAMATE RECEPTOR-LIKE (GLR) proteins in Arabidopsis thaliana are necessary for wound signal propagation in adult-phase rosettes. These proteins provide a unique possibility to identify cellular and subcellular niches necessary for electrical signalling in plants. A model published by the Farmer lab. proposes that both xylem and phloem are important for wound signal transmission. To test this we will localize two GLR proteins (GLR3.3 and GLR3.6) that are involved in leaf-to-leaf wound signal propagation. In addition to localizing the two GLRs we aim to identify interaction partners for these proteins, and to examine the predicted participation of these GLRs in calcium signalling. The questions to be addressed are :1.Where are clade 3 GLR proteins localized at the cellular and subcellular levels?2. What are the interaction partners of GLR3.3 and GLR3.6?3. Do both GLR3.3 and GLR3.6 participate in wound-response calcium signalling?This proposal will rely heavily on microsopy as well as on genetic interaction screens in yeast. One postdoc and one 50% technician working in an electron microscopy facility would be responsible for microscopy aspects. A second postdoc would undertake split ubiquitin screening in yeast to identify proteins that interact with GLR3.3 and GLR3.6. These interactions will be validated in planta, and interactor mutants will be characterised using surface electrophysiology assays, jasmonate signalling assays and herbivore-based defense bioassays. Results from these experiments will be used to direct calcium-sensitive reporters to discrete cellular and subcellular localizations in which GLR proteins are expressed. The goal of the proposal is to produce results of durable value in understanding electrical signal propagation in plants.
Amount: CHF 1,112,000
Funding type: research
Funder scheme: Project funding
Start date: 2018-03-01
End date: 2022-02-28
Investigator: Farmer, Edward Elliston (lead)
Institutions: University of Lausanne, University of Lausanne – LA
Subfield: Plant Science
Domain: Life Sciences
Funded outputs count: 14
Funder award ID: 175566
OpenAlex ID: G8564179505