BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:6-Benzylaminopurine modulates photosynthetic performance and cytok inin homeostasis in Lemna minor under salt stress DTSTART;VALUE=DATE-TIME:20260929T081500Z DTEND;VALUE=DATE-TIME:20260929T083000Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2896@cern.ch DESCRIPTION:Speakers: Vesna Peršić (Department of Biology\, Josip Juraj Strossmayer University of Osijek)\nSalinity primarily reduces plant produc tivity by disrupting the photosynthetic apparatus\, and cytokinins are con sidered to be context-dependent regulators of its tolerance (1-3). This st udy aimed to determine if and how 6-benzylaminopurine (1 μM 6-BA) protect s the photosynthetic apparatus of *Lemna minor* under salt stress (50\, 10 0\, 150 mM NaCl) and to analyze how it modulates accompanying metabolic re sponses. Chlorophyll *a* fluorescence and oxygen exchange were measured to assess plant responses. Simultaneously\, we profiled hormone and cytokini n levels and quantified phenolics\, antioxidant capacity\, pigments\, prol ine\, malondialdehyde (MDA)\, starch\, and antioxidant enzymes. The intera ction between 6-BA and NaCl was the most significant source of variation i n the fluorescence response (PERMANOVA R² = 16.5%\, p < 0.001). 6-BA had a modest cost at low salinity\, but it stabilized PSII at high salinity (r eversing between 100 and 150 mM)\, while the PSI acceptor side declined re gardless. A similar pattern was observed in cytokinin homeostasis\, where 6-BA decreased the endogenous cytokinin pool by half (0.52-fold) and incre ased it by more than twofold at 150 mM (2.24-fold)\, with a reversal occur ring between 50 and 100 mM. Salinity decreased levels of jasmonates\, auxi n\, phenolics\, antioxidant capacity\, and pigments but increased levels o f ABA\, proline\, MDA\, and starch as expected. 6-BA decreased ABA and MDA at all salinity levels and induced a maximal antioxidant response at 100 mM that was lost at 150 mM NaCl. The results suggest that 6-BA improves sa lt tolerance of *L. minor* by coordinating stress-level-dependent adjustme nts of photosynthesis\, respiration\, hormonal and antioxidant metabolism. \n\nhttps://indico.unina.it/event/117/contributions/2896/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2896/ END:VEVENT BEGIN:VEVENT SUMMARY:Single-nuclei transcriptomics reveals a novel frond nutrient-uptak e cell type in duckweeds DTSTART;VALUE=DATE-TIME:20260929T080000Z DTEND;VALUE=DATE-TIME:20260929T081500Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2895@cern.ch DESCRIPTION:Speakers: Alexander Ware* (University of Nottingham)\nDuckweed s are unusual among angiosperms in being able to acquire nutrients through the shoot rather than the root. We previously showed that their roots are dispensable for this ancestral function\, and that they have lost root-bi ased nutrient transporter expression (Ware et al.\, 2023). The cellular bi ology underpinning shoot nutrient uptake\, and its evolution\, remain unkn own.\n\nTo address this\, we generated single-nucleus transcriptomic atlas es of shoots and roots from *Spirodela polyrhiza*\, *Lemna minor* and *Wol ffia australiana*\, alongside the aroid *Pistia stratiotes*\, which indepe ndently colonised the free-floating aquatic niche. Integration of these da tasets across species revealed a previously undescribed cell population\, conserved across all duckweed shoots\, whose identity does not readily cor respond to known cell types in terrestrial monocots. This novel cell type expresses a broad suite of nutrient-uptake genes canonically restricted to the root in terrestrial species. In *Lemna minor*\, optimisation of whole -mount hybridisation chain reaction FISH has spatially localised this cell type to the underside of the frond\, extending one to two cell layers dee p into the abaxial frond body. The abundance of this cell type increases a cross the duckweed genera as the root is reduced\, and it is scarce in roo t-reliant *Pistia*.\n\nWe propose that this cell population constitutes a dedicated nutrient-uptake tissue in the duckweed frond. Functional charact erisation of the cell type\, the transporters it expresses\, and the evolu tion of the regulatory network governing its identity is now ongoing.\n\nh ttps://indico.unina.it/event/117/contributions/2895/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2895/ END:VEVENT BEGIN:VEVENT SUMMARY:DWARPH: An Open Source\, scalable platform for High-Throughput Env ironmental response mapping in Duckweed DTSTART;VALUE=DATE-TIME:20260929T074500Z DTEND;VALUE=DATE-TIME:20260929T080000Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2894@cern.ch DESCRIPTION:Speakers: Lauritsen Markus Dahl (Center for Quantitative Genet ics and Genomics (QGG)\, Aarhus University\, Aarhus\, Denmark)\nDuckweed i s a uniquely fast and tractable plant model\, making it ideal for studying dynamic plant–environment interactions on time scales impossible with c onventional crop or model species. However\, fully harnessing this in duck weed requires sample-level environmental control paired with dense tempora l phenotyping. Standard room-scale or chamber-scale growth systems lack th e targeted precision\, parallel experimentation and imaging frequency requ ired to impose the environment and monitor the plant's response.\n\nWe pre sent **DWARPH** (DuckWeed Automatic Robot for PHenotyping)\, an open-sourc e hardware and software platform engineered to bridge this gap exact gap. DWARPH integrates programmable\, localized control of light intensity and temperature with continuous\, high-frequency imaging. The system supports complex environmental perturbations\, including rapid step changes\, conti nuous ramps\, and cyclic regimes. By automatically synchronizing microenvi ronmental perturbations with image capture\, DWARPH allows researchers to measure phenotypic metrics\, quantitative growth dynamics\, and short-inte rval acclimation responses in real time.\n\nBecause DWARPH relies on acces sible 3D-printed components and a modular architecture\, researchers can d eploy multiple units in parallel to explore broad parameter spaces simulta neously rather than relying on sequential experiments in expensive climate chambers.\n\nThis presentation will focus on the design and engineering o f the DWARPH system. We will present initial data validating system perfor mance and temporal precision for detecting plant responses to microenviron mental perturbations\, followed by a brief overview of future experimental applications.\n\nhttps://indico.unina.it/event/117/contributions/2894/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2894/ END:VEVENT BEGIN:VEVENT SUMMARY:*Lemna trisulca*: Contribution to the Progress in Understanding th e Mechanism of Chloroplast Movements DTSTART;VALUE=DATE-TIME:20260929T073000Z DTEND;VALUE=DATE-TIME:20260929T074500Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2893@cern.ch DESCRIPTION:Speakers: Halina Gabrys (Jagiellonian University\, Faculty of Biochemistry\, Biophysics and Biotechnology)\nChloroplasts relocate within cells to maximize energy capture under limiting light and/or to minimize exposure to excess light. In higher plants these movements are mediated by phototropins\, blue light photoreceptors that control also other light ac climation processes.\n Chloroplast movements share many similarities b etween the aquatic angiosperm *L. trisulca* and *Arabidopsis thaliana*. Th ese include fluence rate-response curves in continuous light and fluence-r esponse profiles obtained with strong light pulses. In both species phosph oinositides and Ca^2+^ participate in signalling\, with a greater role of calcium released from the internal stores. \nThe signalling pathway leadin g to light-induced chloroplast movement may involve GLutamate Receptor-lik e (GLR) channels\, previously shown to participate in light signalling in plants. These ligand-gated ion channels\, structurally homologous to anima l neurotransmitter receptors\, are known to generate Ca^2+^ transients ins ide plant cells. \nWe chose *L. trisulca* to determine the role of GLR cha nnels in chloroplast movements using specific inhibitors. NMDA GLR channel s were shown to participate in the control of chloroplast avoidance respon se in the duckweed. This control occurs in a pH-dependent way\, similar to NMDA receptors operating in animal cells. As the avoidance response is ac tivated only by strong blue light\, these GLR channels are involved in the phototropin2 signalling pathway. GLR AMPA channels\, previously shown to take part in seedling growth\, proved inactive in chloroplast movements. T hus\, we provided evidence that GLR receptors activated by different agoni sts have specialised functions in plants. \nGenetic modification of *L. tr isulca* is desired to get further insight into the mechanism of its blue-l ight-induced chloroplast movements.\n\nhttps://indico.unina.it/event/117/c ontributions/2893/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2893/ END:VEVENT BEGIN:VEVENT SUMMARY:From Duckweed Stress Physiology to D-Amino Acid Signaling: Insight s Across Biological Kingdoms DTSTART;VALUE=DATE-TIME:20260929T071500Z DTEND;VALUE=DATE-TIME:20260929T073000Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2892@cern.ch DESCRIPTION:Speakers: Dr Edna Ben-Izhak Monselise (Ben Gurion Univercity)\ nEdna Ben-Izhak Monselise*\nDepartment of Life Science\, Bergmann Campus\, Ben-Gurion University of the Negev\, Beer-Sheva 8441901\, Israel\nbened@p ost.bgu.ac.il\nCellular stress responses involve extensive metabolic repro gramming. While alterations in amino acid concentrations under stress have been widely documented\, the potential role of amino acid chirality in st ress adaptation remains poorly understood.\nUsing 15N NMR spectroscopy\, s tress-dependent changes in amino acid profiles were investigated in aquati c plant systems\, *Landoltia punctata*. These studies revealed the appeara nce of D-alanine under defined stress conditions (Monselise et al.\, 2015) \, providing evidence for stress-associated D-alanine accumulation in duck weed and suggesting that stereochemical remodeling may represent a compone nt of the plant stress response.\nSubsequent studies in *Escherichia coli* demonstrated stress-associated production and extracellular release of D- glutamate (Monselise\, 2019\; Monselise 2024). The release of D-glutamate into the surrounding medium suggests that stress-induced D-amino acids may function beyond intracellular metabolism and participate in intercellular biochemical communication.\nTaken together\, these observations from both plant and bacterial systems raise the possibility that D-amino acids cons titute conserved elements of stress-response networks across biological ki ngdoms. These findings support a broader conceptual framework in which str ess-induced stereochemical changes contribute to cellular adaptation and s ignaling.\nThe presentation will discuss the evolution of this research\, from duckweed stress physiology to broader questions concerning the role o f D-amino acids in cellular stress responses and their possible relevance to the early stages of cellular dysfunction.\n\nhttps://indico.unina.it/ev ent/117/contributions/2892/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2892/ END:VEVENT BEGIN:VEVENT SUMMARY:Trophic Diversity in Duckweed: Mixotrophy\, More Than the Sum of i ts Extremes DTSTART;VALUE=DATE-TIME:20260929T070000Z DTEND;VALUE=DATE-TIME:20260929T071500Z DTSTAMP;VALUE=DATE-TIME:20260916T051101Z UID:indico-contribution-427-2891@cern.ch DESCRIPTION:Speakers: Hongwei Hou (Shenzhen University of Advanced Technol ogy\, Shenzhen\, China)\nDuckweeds (Lemnaceae) are ideal model plants and valuable biotech resources with diverse trophic strategies\, including mix otrophy. This study investigates the mechanisms and value of mixotrophy in Spirodela polyrhiza 7498. It demonstrates that mixotrophy endows duckweed with significant phenotypic and metabolic flexibility. Under mixotrophic conditions\, duckweed enhances intracellular CO₂ supply through respirat ion\, alleviating photosynthetic limitations and reducing oxidative damage .\nCrucially\, mixotrophy achieves synergistic growth\, with biomass yield significantly exceeding the sum of photoautotrophic and heterotrophic gro wth alone. Experiments confirmed that multiple carbon sources support this growth\, with the mixotrophic growth rate reaching 6.22 and 4.98 times th at of photoautotrophic and heterotrophic modes\, respectively. Besides sup erior biomass\, mixotrophy also promotes protein synthesis and effective n utrient removal from water. Notably\, heterotrophic cultivation favors sta rch accumulation (2.06 times higher than mixotrophy)\, suggesting a combin ed strategy for starch-rich biomass production. This work reveals the syne rgistic advantages of duckweed mixotrophy\, providing a theoretical basis for optimizing biomass production\, high-value product synthesis\, and org anic wastewater remediation.\n\nhttps://indico.unina.it/event/117/contribu tions/2891/ LOCATION:Department of Agricultural Sciences of the University of Napoli F ederico II\, Portici\, Italy Sala Cinese URL:https://indico.unina.it/event/117/contributions/2891/ END:VEVENT END:VCALENDAR