Reconstruction of the absorption spectrum of Synechocystis sp. PCC 6803 optical mutants from the in vivo signature of individual pigments

Abstract

D.F. and J.F.U. conceived the research; D.F. did the experiments; D.F. and J.V.O.-V. performed the simulations; D.F., D.L. and J.F.U. analyzed the data; D.F. wrote the manuscript with contributions from D.L., J.V.O.-V. and J.F.U. D.F. agrees to serve as the author responsible for contact and ensures communication. D.F. was supported by an internal grant of Palacký University Olomouc (no. IGA_PrF_2020_028) and D.L. by the ERDF project "Plants as a tool for sustainable global development" (no.

Structures of a phycobilisome in light-harvesting and photoprotected states

“…For bilins, the transition dipole moment of 13 D were used for the bilins in rod (CPC), and 15 D for bilins in the core (APC) pigments 54 . The spectral overlap J is calculated from the area-normalized spectra of donor and acceptor reported in literature 34,55,56 . Using the full matrix of the excitation transfer rates computed using (1), it is possible to write down a master equation describing the time evolution of probability of exciton residence on i-th chromophore, with a vector-valued y(t) = yi(t) (for i running from 1 to the number of pigments):…”

Shedding light on blue-green photosynthesis: A wavelength-dependent mathematical model of photosynthesis in Synechocystis sp. PCC 6803

“…S4) and compared to in vivo electron pathway fluxes and cellular fluorescence. The quantitative agreement with oxygen production rates supports our pigment-specific implementation of light absorption, which allows for a better assessment of the possible effect of photosystem imbalance [38, 59]. After parameterizing the model to reproduce the electron fluxes in the wild type, we used it to gain in-depth information on the system’s behavior using in-silico mutants.…”

“…To consider the influence of light spectrum on photosynthetic activity, our model takes light as input ( I ) with wavelengths ( λ ) in range between 400 and 700 nm. In this work we performed simulations using the solar spectrum, a fluorescent lamp, cold white LED, warm white LED, and “gaussian LEDs” simulated as Gauss curves with a set peak-wavelength and variance of 10 nm or 0.001 nm (“near monochromatic”) [59] (see Fig. 3a & Fig.…”

“…For calculation of absorbed light we further differentiate between the light absorbed by PSI, PSII, and PBS, based on their reported pigment composition [59] (Fig. 3a).…”

“…To consider the influence of light spectrum on photosynthetic activity, we integrated the estimation of pigment-based light absorption for PSI, PSII, and PBS [53]. This implementation enabled us to simulate various light-adapted cells by updating the parameters corresponding to measured pigment composition and photosystem ratio (e.g.…”