Project Details
Projekt
DiversiPHY and conquer — Diversification of phytochromes during plant terrestrialisation
Applicant
Professor Dr. Andreas Hiltbrunner
Subject Area
Plant Physiology
Term
since 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 440515704
Compared to aquatic habitats, the light conditions on land can be very different, suggesting that plant terrestrialisation required adaptations in photosensory receptors and downstream signalling pathways. Phytochromes (PHYs) are an important class of photoreceptors in plants. In seed plants, ferns, and mosses, independent gene duplications events resulted in small PHY gene families. Functional diversification of PHYs in seed plants into red and far-red light sensing PHYs is well known. However, due to the independent evolution of the PHY diversity in seed plants, ferns, and mosses, functional diversification of PHYs in ferns and mosses cannot be predicted based on studies on seed plant PHYs. Investigating the functional diversification of PHYs is an important goal of the proposed project Work in the frame of the first funding period of MAdLand has shown that the three clades of PHYs in the moss Physcomitrium patens functionally diversified into clades with red and far-red light sensing PHYs, respectively, and into a clade that has dual-specificity and acts in red and far-red light. In the proposed project, we want to investigate functional diversification of PHYs in the fern Ceratopteris richardii using PHY knock-out or knock-down mutants. In addition, we also want to compare the characteristics of red and far-red light induced responses mediated by the different PHYs in Physcomitrium and Ceratopteris to identify similarities and differences that could point to common or lineage-specific mechanisms of light signalling. In contrast to ferns and mosses, liverworts contain a single PHY that is active in red and far-red light. By cross-species complementation studies with the liverwort Marchantia polymorpha and the moss Physcomitrium patens, we then want to identify amino acid residues or motifs that are important for functional diversification of PHYs. Finally, we found that two key components of light signalling in land plants possibly have been acquired in the last common ancestor of land plants and therefore could be innovations in light signalling that facilitated plant terrestrialisation. In the last part of the project, we want to explore this idea.
DFG Programme
Priority Programmes
