Phylogenomic challenges in polyploid-rich lineages: Insights from paralog processing and reticulation methods using the complex genus Packera (Asteraceae: Senecioneae)
Authors: Moore-Pollard, E. R., Ellestad, P., Mandel, J.
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.
The study investigated whether expression of Dormancy-Associated MADS-BOX genes DAM3 and DAM4 inversely correlates with vegetative growth during semi-dormancy induction and breaking in cultivated strawberry. DAM3 and DAM4 expression showed negative correlations with leaf area and petiole length, with DAM4 particularly reflecting growth during dormancy breaking, while no cultivar-specific chill requirement or leaf-type differences were detected. These findings support DAM3 and DAM4 as regulators of semi‑dormancy in Fragaria × ananassa.
The study examined how varying temperature regimes, including cold deprivation and early cold exposure, affect dormancy onset and maintenance in sweet cherry (Prunus avium) flower buds. Phenological monitoring combined with transcriptomic analyses revealed that temperature drives dormancy progression, identifying specific genes and pathways responsive to cold, and uncovering a distinct shallow dormancy phase induced by cold deprivation with a unique molecular signature.
Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.