The study characterizes a conserved RNA structural element named DEAD within DEAD-box helicase genes in land plants, showing that it functions as a sensor of helicase activity to regulate alternative splicing in Arabidopsis thaliana. By modulating the folding of DEAD, the plant balances helicase transcript and protein levels via a negative feedback loop, and loss of this regulation leads to widespread splicing disruptions and severe stress phenotypes.

The study examined how polyploidy, hybridization, and incomplete lineage sorting affect phylogenetic reconstructions in the genus Packera, evaluating several published paralog‑processing pipelines. Results showed that the choice of orthology and paralog handling methods markedly altered tree topology, time‑calibrated phylogenies, biogeographic histories, and detection of ancient reticulation, underscoring the need for careful methodological selection alongside comprehensive taxon sampling.