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Biology subjects

Taylor, J. S.

Publications and source records attributed to Taylor, J. S..

4 recordsLinked to original sources

An Integrated Spatially Resolved Mechanistic Model of Hierarchical Auxin-Cytokinin-Ethylene Crosstalk Underlying Root Growth Inhibition in Arabidopsis

Decoding how plants integrate multiple hormone signals to coordinate growth requires tools capable of resolving pathway interactions at cellular resolution in living tissue. Here we present ACE (Auxin-Cytokinin-Ethylene) and ACE2, proof-of-concept single-locus reporters to simultaneously capture activity of multiple hormones. Deploying ACE alongside well-established reporters, exogenous hormone treatments, and reverse-genetic perturbations of hormone biosynthesis, signaling, and transport in three-day-old etiolated Arabidopsis seedlings, we dissect the spatiotemporal hierarchy governing primary root elongation and root apical meristem (RAM) size. We demonstrate that both ethylene- and cytokinin-triggered root growth inhibition involve a boost of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1)-mediated auxin biosynthesis and AUXIN RESISTANT1 (AUX1)-dependent auxin redistribution. Two spatially distinct auxin responses underlie the respective root growth effects: ethylene expands TAA1-dependent auxin biosynthesis from the root vasculature into the epidermis and promotes AUX1-mediated auxin import into the transition and elongation zones to inhibit cell elongation, while cytokinin confines ethylene-dependent TAA1-boosted activity to the vasculature and drives auxin accumulation in lateral root cap cells to reduce RAM size. Together, these data establish a reciprocal regulatory loop between these hormones, positioning ethylene as a convergence node in auxin-cytokinin crosstalk, and cytokinin as a modulator of the ethylene-auxin interaction. Critically, the changes in cross-activated reporter patterns described for different genetic backgrounds, alongside quantitative assessment of hormone-specific inhibition of the mutants growth, were consistent with the multi-hormone network established over two decades of research, and added cell-type-resolved spatial detail and a proposed hierarchy for the etiolated seedling root. Finally, a second-generation reporter, ACE2, overcomes key technical limitations of ACE, expanding the platforms capacity toward a higher-order multi-hormone monitoring system. These resources expand the Arabidopsis genetic toolkit and provide a generalizable framework instrumental for dissecting multi-hormone signaling hierarchies at the cellular level.

plant biology↗

Glow with the Flow: Reproducible Analysis of Transiently Transformed Protoplasts Using Dual Fluorescent Reporters in R

Transient transformation assays using protoplasts have become a widely employed technique in plant research. Positive fluorescent selection was subsequently developed to assess the effect of transient effector gene expression in only successfully transfected cells using flow cytometry. This process, though effective, often requires considerable manual effort and subjective judgment to quantify reporter gene expression in the intended cell populations. To address this, we introduce a new, open-source workflow based on the R programming language. This method enhances the reproducibility and scalability of such experiments, which enable rapid study of gene regulation and signal transduction in plants. This workflow is available at https://github.com/PlantSynBioLab/positive-fluorescence-selection.

plant biology↗

Identification of potential Auxin Response Candidate genes for soybean rapid canopy coverage through comparative evolution and expression analysis

Glycine max, soybean, is an abundantly cultivated crop worldwide. Efforts have been made over the past decades to improve soybean production in traditional and organic agriculture, driven by growing demand for soybean-based products. Rapid canopy cover development (RCC) increases soybean yields and suppresses early-season weeds. Genome-wide association studies have found natural variants associated with RCC, however causal mechanisms are unclear. Auxin modulates plant growth and development and has been implicated in RCC traits. Therefore, modulation of auxin regulatory genes may enhance RCC. Here, we focus on the use of genomic tools and existing datasets to identify auxin signaling pathway RCC candidate genes, using a comparative phylogenetics and expression analysis approach. We identified genes encoding 14 TIR1/AFB auxin receptors, 61 Aux/IAA auxin co-receptors and transcriptional co-repressors, and 55 ARF auxin response factors in the soybean genome. We used Bayesian phylogenetic inference to identify soybean orthologs of Arabidopsis thaliana genes, and defined an ortholog naming system for these genes. To further define potential auxin signaling candidate genes for RCC, we examined tissue-level expression of these genes in existing datasets and identified highly expressed auxin signaling genes in apical tissues early in development. We identified at least 4 TIR1/AFB, 8 Aux/IAA, and 8 ARF genes with highly specific expression in one or more RCC-associated tissues. We hypothesize that modulating the function of these genes through gene editing or traditional breeding will have the highest likelihood of affecting RCC while minimizing pleiotropic effects.

bioinformatics↗

Light induced changes in starry flounder (Platichthys stellatus) opsin expression and its influence on vision estimated from a camouflage-based behavioural assay.

Correlations between variation in opsin expression and variation in vision are often assumed but rarely tested. We exposed starry flounder (Platichthys stellatus) to either broad spectrum sunlight or green-filtered light in outdoor aquaria for seven weeks and then combined digital-PCR and camouflage experiments to test two hypotheses: i) short-wavelength sensitive opsin expression decreases in a green light environment, and ii) if observed, this change in opsin expression influences colour vision as estimated using a camouflage-based behavioural assay. Of the eight visual opsins measured, Sws1 (UV sensitive) and Sws2B (blue sensitive) expression was significantly lower in fish exposed to green light. However, opsin expression in fish transferred to an arena illuminated with white LED light for three hours after the green light treatment did not differ from broad spectrum controls. Changes in opsin expression in response to artificial light environments have been reported before, but rapid changes over three hours rather than days or weeks is unprecedented. We did not observe a significant difference in a flounders camouflage response based on light environment, although broad spectrum fish increased and green-filter fish decreased the pattern contrast when on the blue-green substrate, and this difference approached significance. This pattern is intriguing considering green-filter fish expressed fewer UV and blue opsins and we recommend increased statistical power for future experiments. Together, our results show that starry flounder opsin expression changes rapidly in response to changes in light environment, however, there is no apparent effect on their visually mediated camouflage.

molecular biology↗