Effects of altered plant cell walls on root jasmonate signalling

• Applicant: Dr. Debora Gasperini
• Subject Area: Plant Physiology ; Plant Genetics and Genomics
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 395537511

Roots of plants growing in nature are constantly subjected to mechanical stress during soil penetration and/or insect attack. In turn, plants have developed elaborate sensing mechanisms that respond to environmental cues and incorporate them in basal development. One such plant response to wounding or herbivory is the production of the phytohormone jasmonate (JA) that induces transcriptional changes required to trigger defense mechanisms. However, how are damage and mechanical signals perceived and how they induce JA production is still unclear. Here, by using roots of Arabidopsis thaliana seedlings, I propose to study how cell wall perturbations impact intracellular hormone (JA) production. First, the project is aimed at characterizing at the cellular and biochemical level two cell wall mutants derived from my postdoctoral research, which exhibit constitutive expression of JA marker genes. This will be coupled to a reverse genetic screen in order to identify the exact component(s) of plant cell walls that alter JA responses. Next, the biological implications of how plant cell walls and hormonal (JA) responses shape plant development and stress responses will be addressed by analysing root growth and defense phenotypes. Finally, we aim to decipher the molecular components involved in cell-wall to plastid signalling by using targeted and untargeted genetic approaches. Overall, these studies are expected to yield a detailed mechanistic description of JA signalling dynamics following alterations in the extracellular matrix, providing insight into the initiation of JA biosynthesis, an area that has been, so far, difficult to investigate. This will inevitably allow a better comparison of the strategies used by plant and animal cells to decode extracellular stimuli, as well as increase our understanding on how roots respond to below-ground pathogens, topics that are of wide fundamental and agronomic interest.

• DFG Programme: Research Grants