Project Details
Projekt
Co-evolution of miRNAs and their targets in sexual reproduction at the sporophyte-gametophyte transition
Applicant
Dr. Sophie de Vries
Subject Area
Plant Cell and Developmental Biology
Evolution and Systematics of Plants and Fungi
Evolution and Systematics of Plants and Fungi
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 431732981
During the evolution of land plants, the dominancy and dependency on each other has changed for sporophytes and gametophytes. With most extreme cases being the bryophytes where the sporophyte is attached to the haploid gametophyte and is not long-lasting and the seed plants, where the sporophytes are independent, making up the major share of the life cycles of the plants. Here, the gametophytes are only shortly occurring sporophyte-dependent structures. Ferns on the other hand can have independent and self-sustainable gametophytes and sporophytes. Yet, the evolutionary scenarios that have led to these differences in dominancy and dependency, are not fully resolved and the molecular programs underpinning the shifts in lineages other than angiosperms remain elusive. Here, we will test whether (i) the gametophyte-sporophyte shifts underlie similar molecular networks in key lineages of land plants and (ii) whether these molecular networks are evolutionarily conserved or rather convergently recruited. sRNAs are key upstream regulators that can, but must not be, highly dynamic with regard to their sequence and the (m)RNA targets they control. They control the initiation of reproduction and have significant effects on reproductive organ formation and fertility in angiosperms. Knowledge on the degree of conservation of sRNA regulatory networks across land plants remains scarce. Thus, we will elucidate the reproductive networks, their evolutionary history and their ancestral character states across land plants using well established representative models: the fern C. richardii, and the two bryophytes M. polymorpha and P. patens. Tracing the functional evolution of miRNA-targeting behavior we will establish how much of these reproductive networks (or parts thereof) are lineage-specific recruits and how much may have been evolutionarily conserved, keeping evolutionary dynamic behavior of miRNA-targeting networks in mind. In this proposal we will (i) address which miRNA families are evolutionary players during gametophyte-sporophyte transition, (ii) infer how this relates to the evolution of reproductive organ patterning and (iii) trace the evolutionary history of these regulatory modules. To answer this, we will first identify miRNAs that are enriched in gametophyte-to-sporophyte transitions, searching for miRNAs homologous to those from angiosperm model systems and identify miRNAs significantly enriched in gametophytic vs. sporophytic tissue in key lineages of non-seed plants. By sequencing gametophytes separately to use the same two-pronged approach to identify conservation and novel recruitment of miRNA-guided modules to reproductive organ formation. Targets of candidate miRNAs will be predicted and confirmed using degradome sequencing using the same gametophytic and sporophytic structures used for sRNA sequencing. Our work will shed light on the evolutionary origin of a key regulatory network in the regulatory biology of all land plants.
DFG Programme
Research Units
