Biology subjects

Alt, J.

Publications and source records attributed to Alt, J..

3 recordsLinked to original sources

bioRxiv2026

Gene-environment interactions govern early regeneration in fir and beech: evidence from participatory provenance trials across Europe

O_LIForest regeneration is shaped by strong demographic filters during germination and early establishment, yet the relative contributions of provenance and environment remain poorly resolved under natural conditions. C_LIO_LIWe combined climate-chamber trials with a continental-scale, field-based citizen science seed-sowing experiment to quantify germination, early phenological development, and three-year post-germination survival fir (Abies spp.) and beech (Fagus spp.) provenances across Europe. Using mixed-effects models and a state-based Markov framework to reconstruct phenological trajectories, we quantified successive demographic filters from seed to established seedling. C_LIO_LIGermination was structured by genotype-by-environment interactions (G x E) in both genera, but with contrasting expression: fir showed broadly parallel environmental responses among provenances and partial concordance between climate-chamber and field, whereas beech showed strong provenance-by-environment responses and weak predictability from controlled conditions. Seed weight was a key axis in beech (lighter seeds germinated more and developed faster), but confounded with geographic differentiation in fir. C_LIO_LIIn contrast to germination, post-establishment survival was dominated by site-level environmental filtering with limited consistent provenance effects, revealing a life-stage shift from fine-scale G x E during germination and early development to broader environmental control of survival--an important consideration for regeneration--based management and assisted migration. C_LI

evolutionary biology↗

bioRxiv2025

Unraveling synergistic and antagonistic effects of simultaneous versus single hypoxia-salt conditions in an evolutionary adapted plant species

Plants frequently encounter simultaneous stressors, requiring complex adaptive responses across regulatory levels. Although morphological and metabolic effects of combined hypoxia-salt stress are known in halophytes, transcriptional impacts remain largely unexplored. This study uses RNA sequencing to analyze Salicornia europaea which is an intertidal salt-marsh plant naturally adapted to these conditions. Combined hypoxia-salt stress induced a distinct gene expression profile in which 16% of genes were exclusively changed. Synergistic, antagonistic, and additive effects were observed across all evaluated functional pathway categories. A data-driven analysis of carbohydrate metabolism, cellular respiration/fermentation, and amino acid pathways revealed that antagonistic effects were more prevalent than synergistic ones in both roots and shoots. Notably higher gene expression levels during hypoxia-salt of sucrose biosynthesis (consistent with salt), sucrose synthase (SUS) and trehalose-6-phosphate phosphatase (TPP, consistent with hypoxia) indicate enhanced sucrose and trehalose metabolism. The parallel down-regulation of invertase genes (consistent with hypoxia) suggests strategic carbon flux redistribution for optimized energy supply. Under hypoxic conditions, lactate dehydrogenase (LDH) expression was up-regulated, indicating active lactate fermentation rather than ethanol production via alcohol dehydrogenase (ADH). Enhanced proline synthesis under combined stress suggests improved osmoprotection. These insights into transcriptional reprogramming under single and combined hypoxia-salt conditions emphasize the intricate regulatory strategies plants utilize to manage concurrent stressors, showcasing their ability to adapt and develop stress resilience.

plant biology↗

bioRxiv2020

Constitutive deletion of translin (Tsn) enhances locomotor response to amphetamine: role of developmental effects

The translin/trax microRNA-degrading enzyme mediates activity-induced changes in translation that underlie several long-lasting forms of cellular plasticity. As translin and trax are expressed in dopaminergic and striatal neurons, we proceeded to investigate whether deletion of Tsn blocks amphetamine sensitization, a long-lasting, translation-dependent form of behavioral plasticity, Although we expected constitutive Tsn deletion to impair amphetamine sensitization, we found, instead, that it enhances the hyperlocomotion produced by the initial dose of amphetamine. Since these mice display elevated adiposity, which alters pharmacokinetics of many drugs, we measured brain amphetamine levels in Tsn knockout mice and found that these are elevated. We also found that diet-induced increases in adiposity in WT mice correlate with elevated brain amphetamine levels. As amphetamine and its analogues are widely used to treat attention deficit disorder, which is associated with obesity, further studies are needed to assess the impact of adiposity on amphetamine levels in these patients.

neuroscience↗