PRE2023-Novel regulators of the MpCOI1-dependent and -independent JA pathways (NOVEL)-PID2022-140766OB-I00

The objectives of this proposal are based on several discoveries achieved in our lab studying the model system Marchantia polymorpha: - The components of the jasmonate signaling pathway are conserved in bryophytes and eudicots. However, the bioactive hormone binding the COI1 receptor that activates the pathway is different: dn-OPDA in Marchantia and JA-Ile in eudicots (Monte et al. 2018; Peñuelas et al. 2019; Monte et al. 2019; Soriano et al. 2022; Kneeshaw et al. 2022; Monte et al. 2022; Chini et al. 2023). - The electrophilic nature of dn-cis-OPDA activates a previously unknown COI1-independent pathway regulating thermotolerance (Monte et al. 2020). MpHSFA and MpREIL are involved in regulating this thermotolerance mechanism. - MpTIFY8, a JAZ-related protein, regulates dn-OPDA responses, suggesting that TIFY8 has a function opposite to that of MpJAZ. - Several MpbHLH TFs regulate secondary metabolism in Marchantia, a plant rich secondary metabolites with a great pharmacological potential almost unexplored so far. In this proposal, the early-stage researcher will be involved in the characterization of different signaling elements (MpTIFY8 and MpbHLHs) modulating the canonical dn-OPDA pathway regulating defenses against different biotic and abiotic stresses. The ESR will also study the function of elements (MpHSFA and MpREIL) of the dn-OPDA regulated, COI1-independent “ancestral” pathway that will help to define plant thermotolerance and adaptive responses.