Sprecher
Beschreibung
Genome size (GS), the amount of DNA in a cell nucleus, varies greatly across land plants, ranging around 2400-fold. Its direct impact on cell size has been linked to key traits such as life strategy, growth habit and rate, habitat preference, geographic range, and diversification rate. Due to genome expansion and contraction mechanisms, GS has varied over time and is hypothesised to have played a significant role in the survival and extinction rates of land plants. Therefore, reconstructing GS variation in fossil plants is essential to better understand its effects on plant evolution and (palaeo)ecology.
Although GS cannot be measured directly in fossil plants, it can be estimated using cell size measurements. Especially its relationship with stomatal guard cell length (GCL) has shown potential as a proxy for palaeo-GS reconstructions. However, further multi-clade analyses are required to improve our understanding of the consistency of the GS–GCL relationship across plant groups.
Here, we thoroughly test the palaeobotanical GS proxy across major plant groups with GCL data from 27 lycophyte species, 97 fern species, 111 gymnosperm species and 658 angiosperm species, assembled from literature and new measurements from herbaria and botanical garden specimens. With a particular focus on non-angiosperm tracheophytes in the newly collected GCL data, we have gathered an extensive GCL dataset that will give more substantial insights into the consistency of the GS–GCL relationship across major plant groups, potentially strengthening the applicability of the palaeobotanical GS proxy and allowing a better understanding of ecological and evolutionary dynamics in land plants.