Estimation of linear and cyclic electron flows in photosynthesis based on 13C-metabolic flux analysis

Yamamoto, Chiaki; Toyoshima, Manabu; Kitamura, Sayaka; Ueno, Yoshifumi; Akimoto, Seiji; Toya, Yoshihiro; Shimizu, Hiroshi

doi:10.1016/j.jbiosc.2020.11.002

Cited by 8 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These simulations indicate that the optimal light intensity could be lower for synthesis reactions requiring more ATP. It has also been suggested that the ATP:NADPH ratio is increased under blue light due to higher CET activity [69, 70]. However, our model did not show a benefit of more chlorophyll-absorbed light on the reactions involving ATP.…”

Section: Resultscontrasting

confidence: 66%

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

Pfennig,

Kullmann,

Zavřel

et al. 2023

Preprint

View full text Add to dashboard Cite

Cyanobacteria hold great potential to revolutionize conventional industries and farming practices with their light-driven chemical production. To fully exploit their photosynthetic capacity and enhance product yield, it is crucial to investigate their intricate interplay with the environment, in a particular light. Mathematical models provide valuable insights for optimising strategies in this pursuit. In this study, we present an ordinary differential equation-based model for cyanobacterium Synechocystis sp. PCC 6803 to assess its performance under various light sources, including monochromatic light. Our model accurately predicts the partitioning of electrons through four main pathways, O2 evolution, and the rate of carbon fixation. Additionally, it successfully captures chlorophyll fluorescence signals, enabling valuable information extraction. We explore state transition mechanisms, favouring PSII quenching over PBS detachment based on theoretical evidence. Moreover, we evaluate metabolic control for biotechnological production under diverse light colours and irradiances. By offering a comprehensive computational model of cyanobacterial photosynthesis, our work enhances understanding of light-dependent cyanobacterial behaviour and supports optimising their metabolism for industrial applications.

show abstract

Section: Resultscontrasting

confidence: 66%

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

Pfennig,

Kullmann,

Zavřel

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…21,22 Based on the mass balances of cofactors between metabolism and photosynthesis, ATP and NADPH production rates in the photosystem can be estimated using the determined flux distributions. [23][24][25] In this study, Synechocystis was cultured under continuous light (CL), fluctuating light (FL), and low-light (LL) conditions (Figure 1). The total number of photons was equal for the CL and FL conditions, and the FL condition consisted of a high-light (HL) phase and LL phase (Figure 1a and b).…”

Section: Introductionmentioning

confidence: 99%

“…In Synechocystis , the central metabolism has been analyzed under various conditions 21,22 . Based on the mass balances of cofactors between metabolism and photosynthesis, ATP and NADPH production rates in the photosystem can be estimated using the determined flux distributions 23–25 …”

Section: Introductionmentioning

confidence: 99%

Effect of light fluctuations on photosynthesis and metabolic flux in Synechocystis sp. PCC 6803

Imada

Yamamoto

Toyoshima

et al. 2023

Biotechnology Progress

Self Cite

View full text Add to dashboard Cite

In nature, photosynthetic organisms are exposed to fluctuating light, and their physiological systems must adapt to this fluctuation. To maintain homeostasis, these organisms have a light fluctuation photoprotective mechanism, which functions in both photosystems and metabolism. Although the photoprotective mechanisms functioning in the photosystem have been studied, it is unclear how metabolism responds to light fluctuations within a few seconds. In the present study, we investigated the metabolic response of Synechocystis sp. PCC 6803 to light fluctuations using 13C‐metabolic flux analysis. The light intensity and duty ratio were adjusted such that the total number of photons or the light intensity during the low‐light phase was equal. Light fluctuations affected cell growth and photosynthetic activity under the experimental conditions. However, metabolic flux distributions and cofactor production rates were not affected by the light fluctuations. Furthermore, the estimated ATP and NADPH production rates in the photosystems suggest that NADPH‐consuming electron dissipation occurs under fluctuating light conditions. Although we focused on the water–water cycle as the electron dissipation path, no growth effect was observed in an flv3‐disrupted strain under fluctuating light, suggesting that another path contributes to electron dissipation under these conditions.

show abstract

“…Photoprotection of diatoms are elevated through NPQ during N starvation ( Liefer et al, 2018 ; Li Z. et al, 2021 ). Photosynthetic electron transport [linear electron flow (LEF) and cyclic electron flow (CEF)] in the thylakoid membrane is very important for photoprotection in plants grown under N stress ( Shikanai, 2007 ; Yamamoto et al, 2021 ). CEF and LEF are essential for balancing the production ratio of ATP/NADPH and for protecting photosystems from impairment by over-reduction of chloroplast stroma ( Lu et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Responses of Linear and Cyclic Electron Flow to Nitrogen Stress in an N-Sensitive Species Panax notoginseng

Zhang

Shuang

et al. 2022

Front. Plant Sci.

View full text Add to dashboard Cite

Nitrogen (N) is a primary factor limiting leaf photosynthesis. However, the mechanism of N-stress-driven photoinhibition of the photosystem I (PSI) and photosystem II (PSII) is still unclear in the N-sensitive species such as Panax notoginseng, and thus the role of electron transport in PSII and PSI photoinhibition needs to be further understood. We comparatively analyzed photosystem activity, photosynthetic rate, excitation energy distribution, electron transport, OJIP kinetic curve, P700 dark reduction, and antioxidant enzyme activities in low N (LN), moderate N (MN), and high N (HN) leaves treated with linear electron flow (LEF) inhibitor [3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU)] and cyclic electron flow (CEF) inhibitor (methyl viologen, MV). The results showed that the increased application of N fertilizer significantly enhance leaf N contents and specific leaf N (SLN). Net photosynthetic rate (Pn) was lower in HN and LN plants than in MN ones. Maximum photochemistry efficiency of PSII (Fv/Fm), maximum photo-oxidation P700+ (Pm), electron transport rate of PSI (ETRI), electron transport rate of PSII (ETRII), and plastoquinone (PQ) pool size were lower in the LN plants. More importantly, K phase and CEF were higher in the LN plants. Additionally, there was not a significant difference in the activity of antioxidant enzyme between the MV- and H2O-treated plants. The results obtained suggest that the lower LEF leads to the hindrance of the formation of ΔpH and ATP in LN plants, thereby damaging the donor side of the PSII oxygen-evolving complex (OEC). The over-reduction of PSI acceptor side is the main cause of PSI photoinhibition under LN condition. Higher CEF and antioxidant enzyme activity not only protected PSI from photodamage but also slowed down the damage rate of PSII in P. notoginseng grown under LN.

show abstract

Estimation of linear and cyclic electron flows in photosynthesis based on 13C-metabolic flux analysis

Cited by 8 publications

References 23 publications

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

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

Effect of light fluctuations on photosynthesis and metabolic flux in Synechocystis sp. PCC 6803

Responses of Linear and Cyclic Electron Flow to Nitrogen Stress in an N-Sensitive Species Panax notoginseng

Contact Info

Product

Resources

About