Biology subjects

Brodsky, V.

Publications and source records attributed to Brodsky, V..

4 recordsLinked to original sources

bioRxiv2026

Subcellular carbohydrate compartmentation and organic acid signatures reveal natural variation in cold acclimation of Arabidopsis thaliana

Plant cold acclimation emerges from coordinated adjustments in photosynthesis, primary metabolism, and intracellular carbon allocation. Yet, the regulatory role of subcellular metabolite compartmentation in natural variation of cold acclimation remains insufficiently understood. Here, we investigated four Arabidopsis thaliana accessions grown either individually or in bulk to determine how growth configuration and genotype shape the metabolism of sugars and organic acids during cold exposure. Using non-aqueous fractionation, we quantified plastidial, cytosolic, and vacuolar sugar pools alongside whole-cell carbohydrates, organic acids, enzyme activities, photosynthetic parameters, and stress markers. A neural-network classifier revealed that subcellular sugar distribution together with sugar amounts and organic acids provided the strongest discriminatory power among accessions, surpassing photosynthetic traits and enzyme activities. Our findings demonstrate that natural variation in cold acclimation is strongly determined by genotype-specific subcellular metabolite architectures, and that the cultivation strategy modulates these intracellular signatures. We conclude that subcellular compartmentation of metabolites represents a cellular control layer for natural variation of cold acclimation and resilience in Arabidopsis thaliana.

plant biology↗

bioRxiv2025

Acclimation of carbon metabolism to a changing environment across a leaf rosette of Arabidopsis thaliana

O_LIPlants need to efficiently and quickly stabilize photosynthesis and carbon metabolism under changing environmental conditions to prevent irreversible tissue damage C_LIO_LIDifferently developed leaves of Arabidopsis thaliana rosettes are typically homogenized for metabolic analyses which might result in significant over- or underestimation of metabolite dynamics. C_LIO_LIHere, photosynthesis and carbon metabolism were analysed in mature and immature leaves of rosettes of natural Arabidopsis accessions originating from southern and northern Europe. Ambient growth condition at 22 {degrees}C was compared to a combined low temperature/elevated light treatment. C_LIO_LIGradients of Fv/Fm and CO2 assimilation rates across leaf rosettes hinted towards tissue-specific acclimation capacities of photosynthesis and carbon metabolism. C_LIO_LIDynamics of carbohydrates and carboxylic acids were integrated with photosynthetic parameters in a quantitative carbon balance model. Model simulations suggested that mature leaf tissue stabilizes acclimation of carbon metabolism in immature leaf tissue and/or other sink tissue. C_LIO_LIIn conclusion, acclimation capacities of photosynthesis to low temperature and elevated light significantly differ within one leaf rosette of Arabidopsis. This directly affects carbon metabolism which shapes the metabolic acclimation capacity of the whole plant. C_LIO_LIIt is suggested to consider such tissue-specific effects which might otherwise be hidden behind a high variance of experimental data. C_LI

plant biology↗

bioRxiv2023

Temperature acclimation of photosynthesis and carbohydrate metabolism are related to the geographical origin of Arabidopsis thaliana

Acclimation is a multigenic trait by which plants adjust photosynthesis and metabolism to cope with a changing environment. Here, natural variation of photosynthetic and metabolic acclimation was analyzed in response to low and elevated temperature. For this, 18 natural accessions of Arabidopsis thaliana, originating from Africa and Europe, were grown at 22{degrees}C before being exposed to 4{degrees}C and 34{degrees}C for cold and heat acclimation, respectively. Amounts of carbohydrates were quantified together with their subcellular distribution across plastids, cytosol and vacuole. Linear electron transport rates (ETRs) were determined together with maximum quantum efficiency of photosystem II (Fv/Fm) for all growth conditions and under temperature fluctuation. Under elevated temperature, residuals of ETR under increasing photosynthetic photon flux densities were found to significantly correlate with the longitudinal gradient of the geographic origin of accessions indicating a naturally occurring east-west gradient of photosynthetic acclimation capacities. Further, in heat acclimated plants, vacuolar fructose amount was found to positively correlate with longitude while plastidial and cytosolic amounts were found to be negatively correlated. Plastidial sucrose concentrations were found to positively correlate with maximal ETRs under fluctuating temperature indicating a stabilizing role within the chloroplast. In summary, our findings revealed specific subcellular carbohydrate distributions which contribute differentially to photosynthetic efficiencies of natural Arabidopsis thaliana accessions across a longitudinal gradient. This sheds light on the relevance of subcellular metabolic regulation for photosynthetic performance in a fluctuating environment and supports the physiological interpretation of naturally occurring genetic variation of temperature tolerance and acclimation.

plant biology↗

bioRxiv2021

Integration of plant carbohydrate dynamics by Fourier polynomials

Quantification of system dynamics is a central aim of mathematical modelling in biology. Defining experimentally supported functional relationships between molecular entities by mathematical terms enables the application of computational routines to simulate and analyse the underlying molecular system. In many fields of natural sciences and engineering, trigonometric functions are applied to describe oscillatory processes. As biochemical oscillations occur in many aspects of biochemistry and biophysics, Fourier analysis of metabolic functions promises to quantify, describe and analyse metabolism and its reaction towards environmental fluctuations. Here, Fourier polynomials were developed from experimental time-series data and combined with block diagram simulation of plant metabolism to study heat shock response of photosynthetic CO2 assimilation and carbohydrate metabolism. Findings suggest that increased capacities of starch biosynthesis stabilize photosynthetic CO2 assimilation under transient heat exposure. Among soluble sugars, fructose concentrations were observed to fluctuate least under heat exposure which might be the consequence of high respiration rates under elevated temperature. Finally, Col-0 and two mutants of Arabidopsis thaliana with deficiencies in starch and sucrose metabolism were discriminated by fundamental frequencies of Fourier polynomials across different experiments. This suggests balance modelling based on Fourier polynomials as a suitable approach for mathematical analysis of dynamic plant-environment interactions. HighlightA balance equation model is developed to quantify effects of transient heat exposure on plant carbon assimilation. The model is based on Fourier polynomials for quantitative assessment of system dynamics.

plant biology↗