Biology subjects

Kunz, H.-H.

Publications and source records attributed to Kunz, H.-H..

17 recordsLinked to original sources

bioRxiv2026

Experimental and computational analyses of KEA3-dependent photosynthetic responses uncover species-specific molecular variation

- NPQ relaxation is thought to limit crop biomass and yield under natural, fluctuating light. The thylakoid K/H exchanger KEA3 accelerates NPQ relaxation by lowering the lumen proton concentration and thus should affect biomass and yield under frequent light fluctuations. - To investigate the impact of KEA3-dependent NPQ relaxation on Solanum lycopersicum (tomato), we generated knock-out and over-expression lines and measured NPQ, gas exchange, biomass and yield. We constructed a mathematical model to compare species-specific NPQ relaxation dynamics in tomato and the model plant Arabidopsis thaliana. - In polytunnel and controlled fluctuating-light conditions, KEA3-mediated NPQ relaxation did not translate into consistent differences in tomato biomass or yield. Although KEA3 levels strongly affected NPQ relaxation, more so than in A.thaliana, the resulting effects on CO2 assimilation were minor. Modeling results indicated that, besides minor changes in KEA3 regulation, the activity of PsbS, the primary NPQ trigger, largely determines the species-specific differences in NPQ relaxation. Structural models from both species predict sequence variation with impact on PsbS activation. - Manipulating KEA3 levels in tomato did not link NPQ relaxation with productivity. However, the results support robust cross-species mathematical model that accurately predicts the molecular interactions governing NPQ dynamics.

plant biology↗

bioRxiv2026

The Conserved N-Terminal Extension of AtKEA1 Is Largely Dispensable for Plastid Function but Contributes to Potassium Homeostasis

Members of the K efflux antiporter (KEA) family fulfill key roles in plastids and the endomembrane system. Plants and green algae possess at least one KEA mediating K/H exchange across the plastid inner envelope (IE) membrane. Recently, IE KEAs were shown to be essential for plastid gene expression (PGE), chloroplast development, and photosynthesis. Plants lacking these antiporters exhibit reduced stromal protein synthesis and accumulation of unprocessed rRNA precursors. KEA proteins comprise a conserved monovalent cation/proton antiporter 2 (CPA2) domain and a regulatory K transport and NAD-binding (KTN) domain. IE KEAs are distinguished by an additional [~]500-amino-acid N-terminal extension containing a coiled-coil (CC) domain embedded within a largely intrinsically disordered region (IDR). Intrigued by this unusual architecture, we performed phylogenetic analyses, revealing that this N-terminal fusion arose early and has been conserved throughout the green lineage. We then investigated the oligomeric state, native distribution, and function of the N-terminal domain. Using Arabidopsis thaliana, we found that IE KEAs localize to discrete clusters within the inner envelope membrane and assemble into complexes of approximately 600 kDa. Finally, complementary approaches using a functional KEA1 variant lacking the core N-terminal domains (KEA1{Delta}N) indicate that this extension plays a regulatory rather than an essential role. Our findings uncover an evolutionarily ancient regulatory module that shapes the molecular organization and function of IE KEAs, advancing our understanding of plastid ion and pH homeostasis and plastid ribosome integrity. One-sentence summaryPlastid KEA1/2 proteins feature a unique N-terminal extension that modulates potassium transport activity in a yet unknown manner but is not essential for normal plant growth under ambient conditions.

plant biology↗

bioRxiv2026

pamiR: INVESTIGATING PLANT CELLS ONE ORGANELLE AT A TIME

Functional genetic redundancy (FGR) within gene families limits the discovery of gene function in plants because single-gene perturbations often fail to produce informative phenotypes. Artificial microRNAs (amiRNAs) provide a strategy to silence multiple related genes simultaneously. However, the existing amiRNA-based libraries used for genetic gene function discovery in plants do not account for the subcellular localization of gene products, which can lead to pleiotropic or difficult-to-interpret phenotypes. Plastids are essential plant cell organelles that integrate central metabolic and signaling processes, including photosynthesis, hormone biosynthesis, and environmental responses. Here we introduce pamiR, a plastid-targeted amiRNA library designed to enable organelle-specific gene function discovery in Arabidopsis thaliana. Using plastid proteomic datasets, we identified high-confidence plastid-localized proteins and designed amiRNAs to target their gene(s) (families) minimizing FGR. This amiRNA library was introduced in a vector with fluorescence-accumulating seed technology enabling rapid, herbicide-free selection and screening in the first generation. Validation by next-generation sequencing, confirmed high representation and uniform distribution of amiRNAs within pamiR. Proof-of-concept screens recovered mutants affecting known and additional candidate genes involved in photosynthesis and abscisic acid biosynthesis. Therefore, the pamiR library provides a fast platform for plastid-focused genetic screens that is compatible with existing mutant collections. One-sentence summaryThe plastid amiRNA (pamiR) library enables organelle-specific forward genetics without functional genetic redundancy.

plant biology↗

bioRxiv2025

Conserved and Lineage-Specific Roles of KEA-Mediated Ion Homeostasis in Chlamydomonas

In Arabidopsis thaliana, seamless plastid gene expression and development depend on finely balanced ion homeostasis across the inner envelope (IE) membrane, maintained by the K/H antiporters AtKEA1/2. To assess whether these functions are retained across mono- and polyplastidic representatives of the green lineage, we studied CrKEA1, the sole IE KEA homolog in the unicellular alga Chlamydomonas reinhardtii. Using CRISPR/Cas9, we generated a Cr-kea1 knockout mutant that exhibits impaired photoautotrophic growth, chloroplast deformation, and photoinhibition. Transcriptomics revealed strong induction of ribosome biogenesis genes and reduced abundance of transcripts associated with cell and plastid division. Further RNA analyses confirmed defects in stromal rRNA maturation of Cr-kea1, paralleling observations from Arabidopsis kea1kea2 mutants. Expression of CrKEA1 in Arabidopsis rescued growth and rRNA maturation in At-kea1kea2, demonstrating functional continuity after the ancient divergence between the two lineages. Cross-species transcriptomic comparisons further revealed that IE KEA loss elicits both shared and species-specific transcriptional responses: PhANG repression was conserved between algae and plants, whereas activation of the chloroplast unfolded protein response (cpUPR) and reduced expression of genes tied to cell-cycle and plastid fission occurred only in Chlamydomonas. Single-cell time-lapse imaging confirmed that Cr-kea1 exhibits an increased frequency of aberrant cytokinesis, unequal division, and division failure. Our findings demonstrate that while IE KEA transporters fulfill conserved roles in maintaining the conditions for plastid gene expression, their integration into broader cellular networks has diverged between unicellular chlorophytes and embryophytes (land plants). This underscores a lineage-dependent tuning of plastid-nucleus communication shaped by organismal complexity and plastid number. One-sentence summaryDisruption of KEA-mediated chloroplast ion homeostasis in Chlamydomonas reinhardtii reveals conserved and lineage-specific control of plastid rRNA processing and cell cycle progression.

plant biology↗

bioRxiv2025

Cell wall integrity and elicitor peptide signaling modulate antimicrobial defense in Arabidopsis via jasmonic acid

Plant cell walls constitute dynamic barriers that are essential for defense against pathogens. The receptor kinase THESEUS1 (THE1) monitors cell wall integrity (CWI) and contributes to pathogen resistance in Arabidopsis, but the underlying mechanisms remain unclear. Here we show that THE1-dependent CWI signaling induces accumulation of the antimicrobial metabolite camalexin upon cell wall damage (CWD) caused by cellulose biosynthesis inhibition or fungal infection. CWD alters THE1 plasma membrane nanodomain organization and involves calcium signaling components that modulate camalexin production. Induction of camalexin requires jasmonic acid (JA)-dependent expression of the transcription factors MYB47 and MYB95. In line with its antagonistic function on CWI signaling, the plant elicitor peptide Pep3 suppresses camalexin biosynthesis downstream of THE1 by inhibiting JA-dependent pathways. Our findings reveal a regulatory network where CWI and Pep3 signaling modulate antimicrobial defense via JA-mediated camalexin production. This network requires independent CWD-induced pathways, providing insights into how plants balance defense activation and suppression in response to cell wall stress.

plant biology↗

bioRxiv2025

The chloroplast ionome shines new light on organellar Fe homeostasis

Annually, chloroplasts fix 258 billion tons of CO2 through photosynthesis. Photosynthesis and other biochemical pathways require specific amounts of metal ions in the organelle. Transport proteins in the plastid inner envelope maintain the organellar ion homeostasis. Despite substantial progress over the last decades, many genes encoding for plastid ion channels and ion carriers or their regulators remain unknown. To fill this knowledge gap, detailed information on the elemental composition of chloroplasts i.e., a plastid ionome, is needed. This will allow to compare mutants of transporter candidates with wild-types. Here, we provide quantitative descriptions of chloroplast ionomes from Arabidopsis thaliana, the metal hyperaccumulator Arabidopsis halleri, Pisum sativum, and Nicotiana benthamiana and analyze similarities and distinctions. Using A. thaliana, we show that plastid ionomes can be genetically manipulated. Chloroplasts of oligopeptide transporter3 (opt3)-deficient mutants contain 14-fold more iron, which they deposit into stromal FERRITIN. The removal of FERRITIN in opt3 mutants leads to a substantial decrease in plastid and leaf iron pointing to important signaling linked to the chloroplast ionome. Our study reveals that chloroplasts can be turned into large iron storages. Since crop biofortification to fight hidden hunger has become a global mission, this research provides groundwork to reach this goal.

plant biology↗

bioRxiv2025

Role of Chloroplast Lipid-Remodelling Protein 23 During Cold Acclimation in Arabidopsis thaliana

Cold acclimation is a crucial physiological process that enables plants to adapt to low temperatures. A key aspect of this adaptation is lipid remodeling, which preserves membrane fluidity and integrity under cold stress. Proteins of the chloroplast envelope membranes are increasingly recognized for their role in acclimation to changing environmental conditions. While lipid synthesis occurs at the inner envelope membrane, little is known about specific proteins involved in lipid remodeling during cold acclimation. In this study, we investigate the role of Chloroplast Lipid Remodeling Protein 23 (CLRP23) as a component of the inner chloroplast envelope membrane. Subcellular fractionation combined with protease protection assays provided evidence for its orientation toward the intermembrane space. To explore its function, we analyzed the physiological performance and lipid composition in CLRP23-deficient mutant plants. Under cold stress, we observed significant impairments in photosynthesis and exaggerations in galactolipid response, suggesting CLRP23 is involved in lipid remodeling. Lipid overlay assays, supported by in silico docking analyses, demonstrate that CLRP23 can directly interact with chloroplast lipids, including galactolipids. Complementary transcriptomic and proteomic analyses reveal broader effects on cold-responsive pathways, supporting the view that CLRP23 contributes to the integration of membrane and metabolic responses during acclimation. These findings expand our understanding of protein-mediated processes during cold acclimation.

plant biology↗

bioRxiv2025

The evolutionary history of plastid outer envelope proteins - a structure-sequence comparison

Plant metabolism heavily relies on chloroplasts, derived from once free-living organisms. However, how two distinct organisms merged into one remains currently only partially understood. Protein-mediated metabolite exchange across the double-membrane chloroplast envelope is essential for plant cell function. Here, we investigate the evolutionary origins of outer envelope proteins (OEPs) involved in these transport processes. The mosaic nature of the nuclear genome and the deep evolutionary distance since plastid acquisition are major challenges. To address them, we combine sequence-based analyses with emerging structure-based tools, which together enable more sensitive evolutionary comparisons than traditional methods alone. To uncover distinct evolutionary trajectories, we focused on five OEP families: four {beta}-barrel proteins involved in metabolite transport and JASSY, the first published OPDA transporter. We found that the {beta}-barrel proteins were recruited in a stepwise manner and structural homologs of some OEPs point to early recruitment via endosymbiotic gene transfer (EGT). Notably, OEP40 shows a recent structural rearrangement, lacking clear structural homologs in plants other than Arabidopsis, yet retaining sequence conservation across all major land-plant lineages. The JASSY-like family is found across plastid-bearing species, while true JASSY orthologs emerged in embryophytes likely via a stable recruitment of the characteristic lipid-binding domain. Overall, our findings highlight the dynamic nature of the chloroplast outer envelope and show how new functions evolved through structural reshaping and novel domain recruitment. Structure-based approaches thus powerfully complement sequence data, offering more in-depth insight into the evolution of plastid transport systems.

evolutionary biology↗

bioRxiv2025

Advanced illumination-imaging reveals photosynthesis-triggered pH, ATP and NAD redox signatures across plant cell compartments

Photosynthesis provides energy and organic substrates to most life. In plants, photosynthesis dominates chloroplast physiology but represents only a fraction of the tightly interconnected metabolic network that spans the entire cell. Here, we explore how photosynthetic activity affects energy physiology within and beyond the chloroplast. We developed a new standard for the live-monitoring of subcellular energy physiology by combining confocal imaging of genetically encoded fluorescent protein biosensors with advanced on-stage illumination technology to investigate pH, MgATP2- and NADH/NAD+ dynamics at dark-light transitions in Arabidopsis mesophyll cells. Our findings reveal a stromal alkalinization signature induced by photosynthetic proton pumping, extending to the cytosol and mitochondria as an alkalinization wave. Photosynthesis leads to increased MgATP2- levels in both the stroma and cytosol. Additionally, we observed reduction of the NAD pool driven by photosynthesis-derived electron export. Arabidopsis lines defective in chloroplast NADP- and mitochondrial NAD-dependent malate dehydrogenases show more reduced cytosolic NAD redox status even in darkness, highlighting the involvement of chloroplasts and mitochondria in shaping cytosolic redox metabolism via malate metabolism. Our study sets a novel methodological standard for precision live-monitoring of photosynthetic cell physiology. Applying this technology reveals signatures of photosynthetic physiology within and beyond the chloroplast with unprecedented resolution. Those signatures link photosynthetic activity and the fundamental biochemical functions of phototrophic cells. Significance statementBy applying novel live microscopy monitoring using fluorescent protein biosensors in plant cells, we reveal that dark-light transitions trigger profound re-orchestration of subcellular pH, ATP and NAD redox physiology not limited to chloroplasts but extending into the cytosol and the mitochondria.

plant biology↗

bioRxiv2025

Catch & Release - rapid cost-effective protein purification from plants using a DIY GFP-Trap-protease approach

The purification of proteins is the foundation to study their structure, function, biochemical properties, and interaction partners. In plant research, unique challenges arise from the complexity of plant tissues, interference of secondary metabolites, and sometimes the low abundance of target proteins. Many conventional plant protein purification methods rely on expensive reagents, multi-step procedures, and labor-intensive workflows, limiting their feasibility for many applications. Here, we present the "Catch & Release" system, a cost-effective, fast and reliable one-step purification workflow for the isolation of soluble and membrane-bound proteins from plant tissues. The Catch & Release toolbox includes a vector set, a homemade GFP-trap and homemade proteases. Catch & Release vectors streamline cloning and transgenic plant selection through the Fluorescence-Accumulating Seed Technology (FAST), which marks positive transformants with a strongly fluorescing seed coat. Each plasmid consists of four, easy to exchange, modules: a plant promoter, a cloning dropout marker, protease cleavage sites, and seven different epitope tags, including an innovative dual-fluorescent tag, providing flexibility for diverse experimental needs. The in vivo functionality of all modules has been confirmed. Besides enabling standard molecular biological experimentation, our vector set in combination with homemade GFP-trap and proteases enables efficient and rapid isolation of soluble and high molecular weight membrane proteins directly from plants. By following our detailed reagent preparation instructions, purification costs can be decreased hundred-fold compared to the commercially available options.

plant biology↗

bioRxiv2025

Expression levels of the Band-7 protein FLOTILLIN modulate salt tolerance, growth and development in the moss Physcomitrium patens

The Band-7 proteins, known as FLOTILLINs (FLOT), are present at the plasma membranes of most land plants. They function in clathrin-independent endocytosis and contribute to nodule formation following symbiotic infections. This study reveals that the single FLOT variant in Physcomitrium patens is located at the thylakoid membranes in chloroplasts, serving an unanticipated function. Phenotypic analysis of knockout and overexpression lines demonstrates that PpFLOT overexpression significantly impairs the high salinity tolerance of P. patens. Additionally, liquid protonema cultures of PpFLOT-OEX lines exhibited a distinct color change due to necrotic events and developed brachycyte-like cells. These changes correlate with the strength of PpFLOT expression and do not occur when these lines are cultivated on solid medium. Our study found that PpFLOT-OEX lines display increased chlorophyll and H2O2 production. We also discovered that PpFLOT is regulated by ABA and light, and its high expression can potentially affect retrograde signaling. Metabolomics and proteomics analyses revealed changes in the pigment and lipid composition as well as differentially accumulated proteins in PpFLOT mutant lines. We also observed changes in the expression of ion-transport related genes, accumulation of lipids crucial during pathogen defense, and differentially accumulated proteins taking part in multiple metabolomic pathways. Consequently, our study suggests a novel role for chloroplastic PpFLOT in plant terrestrialization, as it is putatively involved in Ca2+ and reactive oxygen species (ROS) signaling in response to abiotic and biotic stress, along with the light-dependent regulation of chlorophyll biosynthesis.

plant biology↗

bioRxiv2025

Plant cells tolerate high rates of organellar mistranslation

Bacteria can trigger protein mistranslation to survive stress conditions 1. Mitochondria and plastids evolved from bacteria and therefore also use prokaryotic-type expression machineries to synthesize proteins. However, fungi and animal mitochondria are highly sensitive to mistranslation, which for instance manifests in lethal mitochondrial cardiomyopathy disorder 2. The response in plant cells is unknown. Glutaminyl-transferRNAs (Gln-tRNAGln) of bacteria, mitochondria, and plastids are synthesized indirectly 3,4. Initially, tRNAGln gets charged with glutamate. Subsequently, Gln is produced through trans-amidation by the aminoacyl-tRNA amido-transferase complex GatCAB. Consequentially, affected GatCAB activity results in pools of misloaded Glu-tRNAGln. Here we show that Arabidopsis mutants with decreased GatCAB level provide global insights into organellar mistranslation in plants. Proteomics revealed Gln-to-Glu misincorporation in plastid- and mitochondrially-expressed protein complexes with only modest abundance changes in mutant plants. Plastids appear more lenient to mistranslation as they exhibit much higher Gln-to-Glu misincorporation. Through efficient compensatory mechanisms, mutant plants display surprisingly subtle phenotypes. However, their acclimation to temperature stress differs. Interestingly, wild-type plants under similar stress also have altered Gln-to- Glu misincorporation. Our study shows that the response towards organellar mistranslation varies among eukaryotes. In plants, this knowledge can be used to improve stress tolerance.

plant biology↗

bioRxiv2024

Anatomics MLT, an AI tool for large scale quantification of ultrastructural traits

The ever increasing breadth of biological knowledge has led to recent efforts to combine information from various fields into cell- or tissue atlases. Anatomical features are the structural basis for such efforts, but unfortunately large scale analysis of subcellular anatomical traits is currently a missing feature. Similarly, small phenotypic alterations of organelle- or cell-specific anatomical traits, such as an increase of the total volume or the number of mitochondria in response to certain stimuli, are currently hard to quantify. To provide tools to extract quantitative information from available 3D microscopic datasets generated with methods such as serial block face scanning electron microscopy we a) developed much improved fixation and embedding protocols for plants to drastically reduce processing artifacts and b) generated an easy-to-use AI tool for quantitative analysis and visualization of large-scale data sets. We make this tool available as open source.

cell biology↗

bioRxiv2023

Degradation of Fatty Acid Export Protein1 by Rhomboid-Like Protease11 Contributes to Cold Tolerance in Arabidopsis

Plants need to adapt to different stresses to optimize growth under unfavorable conditions. The abundance of the chloroplast envelope located Fatty Acid Export Protein1 (FAX1) decreases after the onset of low temperatures. However, it was unclear how FAX1 degradation occurs and whether altered FAX1 abundance contributes to cold tolerance in plants. The rapid cold-induced increase in rhomboid-like protease11 (RBL11) transcript, the physical interaction of RBL11 with FAX1, the specific FAX1 degradation after RBL11 expression, and the absence of cold-induced FAX1 degradation in rbl11 loss-of-function mutants suggest that this enzyme is responsible for FAX1 degradation. Proteomic analyses showed that rbl11 mutants have higher levels of FAX1 and other proteins involved in membrane lipid homeostasis, suggesting that RBL11 is a key element in the remodeling of membrane properties during cold. Consequently, in the cold, rbl11 mutants show a shift in lipid biosynthesis towards the eukaryotic pathway, which coincides with impaired cold tolerance. To demonstrate that cold sensitivity is due to increased FAX1 levels, FAX1 overexpressors were analyzed. rbl11 and FAX1 overexpressor mutants show superimposable phenotypic defects upon exposure to cold temperatures. Our results show that the cold-induced degradation of FAX1 by RBL11 is critical for Arabidopsis to survive cold and freezing periods. One sentence summaryDegradation of the inner envelope protein Fatty Acid Export1 via Rhomboid Like Protease11 represents a critical process to achieve cold and frost tolerance in Arabidopsis

plant biology↗

bioRxiv2023

Probing the in-situ volumes of Arabidopsis leaf plastids using 3D confocal and scanning electron microscopy

Leaf plastids harbor a plethora of biochemical reactions including photosynthesis, one of the most important metabolic pathways on earth. Scientists are eager to unveil the physiological processes within the organelle but also their interconnection with the rest of the plant cell. An increasingly important feature of this venture is to use experimental data in the design of metabolic models. A remaining obstacle has been the limited in situ volume information of plastids and other cell organelles. To fill this gap for chloroplasts, we established three microscopy protocols delivering in situ volumes based on: 1) chlorophyll fluorescence emerging from the thylakoid membrane, 2) a CFP marker embedded in the envelope, and 3) calculations from serial block-face scanning electron microscopy (SBFSEM). The obtained data were corroborated by comparing wild-type data with two mutant lines affected in the plastid division machinery known to produce small and large mesophyll chloroplasts, respectively. Furthermore, we also determined the volume of the much smaller guard cell plastids. Interestingly, their volume is not governed by the same components of the division machinery which defines mesophyll plastid size. Based on our three approaches the average volume of a mature Col-0 wild-type mesophyll chloroplasts is 93 {micro}m3. Wild-type guard cell plastids are approximately 18 {micro}m3. Lastly, our comparative analysis shows that the chlorophyll fluorescence analysis can accurately determine chloroplast volumes, providing an important tool to research groups without access to transgenic marker lines expressing genetically encoded fluorescence proteins or costly SBFSEM equipment. Significance statement -sentence summaryThis work describes and compares three different strategies to obtain accurate volumes of leaf plastids from Arabidopsis, the most widely used model plant. We hope our contribution will support quantitative metabolic flux modeling and spark other projects aimed at a more metric-driven plant cell biology.

plant biology↗

bioRxiv2023

Probing the physiological role of the plastid outer-envelope membrane using the oemiR plasmid collection

Plastids are the site of complex biochemical pathways, most prominently photosynthesis. The organelle evolved through endosymbiosis with a cyanobacterium, which is exemplified by the outer envelope (OE) membrane that harbors more than 40 proteins in Arabidopsis. Their evolutionary conservation indicates high significance for plant cell function. While a few proteins are well-studied as part of the protein translocon complex the majority of OE protein (OEP) functions is unclear. Gaining a deeper functional understanding has been complicated by the lack of observable loss-of-function mutant phenotypes, which is often rooted in functional genetic redundancy. Therefore, we designed OE-specific artificial micro RNAs (oemiRs) capable of downregulating transcripts from several loci simultaneously. We successfully tested oemiR function by performing a proof-of-concept screen for pale and cold-sensitive mutants. An in-depth analysis of pale mutant alleles deficient in the translocon component TOC75 using proteomics provided new insights into putative compensatory import pathways. The cold stress screen not only recapitulated three previously known phenotypes of cold-sensitive mutants, but also identified four mutants of additional oemiR OE loci. Altogether our study revealed a role of the OE to tolerate cold conditions and showcasts the power of the oemiR collection to research the significance of OEPs.

plant biology↗

bioRxiv2019

Dynamic light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

BackgroundOver the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field. ResultsWe show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup. ConclusionsWith material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

plant biology↗