A thermoluminescence study of the effects of nitrite on photosystem II in spinach thylakoids

Sahay, Archna; Jajoo, Anjana; Bharti, Sudhakar

doi:10.1002/bio.898

Cited by 6 publications

(8 citation statements)

References 29 publications

(29 reference statements)

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“…6). Our TL data are consistent with the observation of Sahay et al (31) that nitrite inhibited the OEC on the donor side of PSII, as indicated by the suppression of the Q band and the upshift of the B band in nitrite-treated isolated chloroplasts. The increase in the stability of the S 2 state arises from the inactivation of the donor side (43).…”

Section: Discussionsupporting

confidence: 93%

“…Furthermore, the reaction center is a more sensitive target of nitrite stress than is the donor side of PSII. Our results therefore broaden the incomplete view that the donor side of PSII is the primary target of nitrite stress (31). measured at 100 ms after the fourth flash (ΔF 4 ϭ F 400 ms /F o Ϫ 1), which is controlled almost entirely by inactive centers.…”

Section: Discussionsupporting

confidence: 62%

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The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803

Zhang

Zhu

et al. 2017

Appl Environ Microbiol

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Nitrite, a common form of inorganic nitrogen (N), can be used as a nitrogen source through N assimilation. However, high levels of nitrite depress photosynthesis in various organisms. In this study, we investigated which components of the photosynthetic electron transfer chain are targeted by nitrite stress in Synechocystis sp. strain PCC 6803 cells. Measurements of whole-chain and photosystem II (PSII)-mediated electron transport activities revealed that high levels of nitrite primarily impair electron flow in PSII. Changes in PSII activity in response to nitrite stress occurred in two distinct phases. During the first phase, which occurred in the first 3 h of nitrite treatment, electron transfer from the primary quinone acceptor (Q A ) to the secondary quinone acceptor (Q B ) was retarded, as indicated by chlorophyll (Chl) a fluorescence induction, S-state distribution, and Q A Ϫ reoxidation tests. In the second phase, which occurred after 6 h of nitrite exposure, the reaction center was inactivated and the donor side of photosystem II was inhibited, as revealed by changes in Chl fluorescence parameters and thermoluminescence and by immunoblot analysis. Our data suggest that nitrite stress is highly damaging to PSII and disrupts PSII activity by a stepwise mechanism in which the acceptor side is the initial target. IMPORTANCE In our previous studies, an alga-based technology was proposed to fix the large amounts of nitrite that are released from NO X -rich flue gases and proved to be a promising industrial strategy for flue gas NO X bioremediation (W. Chen et al., Environ Sci Technol 50:1620 -1627, https://doi.org/10.1021/ acs.est.5b04696; X. Zhang et al., Environ Sci Technol 48:10497-10504, 2014, https:// doi.org/10.1021/es5013824). However, the toxic effects of high concentrations of nitrite on algal cells remain obscure. The analysis of growth rates, photochemistry, and protein profiles in our study provides important evidence that the inhibition by nitrite occurs in two phases: in the first phase, electron transfer between Q A Ϫ and Q B is retarded, whereas in the second, the donor side of PSII is affected. This is an excellent example of investigating the "early" inhibitory effects (i.e., within the first 6 h) on the PSII electron transfer chain in vivo. This paper provides novel insights into the mechanisms of nitrite inhibition of photosynthesis in an oxygenic phototrophic cyanobacterium.

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Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 62%

The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803

Zhang

Zhu

et al. 2017

Appl Environ Microbiol

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“…These results, thus, suggested that the effects of nitrite were mainly on the donor side of PS II. Our results are in good agreement with the earlier reports (Sahay et al 2006a, 2006b), which suggested that the effects of nitrite are on the donor side of PS II.…”

Section: Discussionsupporting

confidence: 94%

“…Further, Jajoo and Bharti (1993) showed that the presence of chloride lowers the amount of bicarbonate required to overcome the inhibition induced by nitrite or formate. Loss of S 2 state multiline signal (Jajoo et al 2005) and changes observed in the thermoluminescence studies (Sahay et al 2006b) in nitrite‐treated samples have shown that nitrite probably acts on the donor side of PS II.…”

Section: Introductionmentioning

confidence: 99%

Relation between the mode of binding of nitrite and the energy distribution between the two photosystems

Singh

Jajoo

Sahay

et al. 2007

Physiologia Plantarum

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The reversibility of nitrite‐induced inhibition in relation to energy distribution between the two photosystems was studied in spinach thylakoid membranes. Measurements of electron transfer rate catalyzed by photosystem I (PS I) and photosystem II (PS II), chlorophyll a (Chl a) fluorescence induction kinetics, S2 state multiline spectra, and room temperature electron paramagnetic resonance (EPR) signals indicated that nitrite anions bind PS II in two ways: dissociable (loose) and non‐dissociable (tight). The inhibition caused by the dissociable binding was reversible in washed (nitrite‐treated samples washed with nitrite‐free medium) samples, while the inhibition caused by the non‐dissociable binding was irreversible. At 77 K, an increase in absorption cross section of PS I (as inferred from the excitation spectra of Chl a fluorescence) and a decrease in absorption cross section of PS II in nitrite‐treated sample when compared with sample washed with nitrite‐free medium and control sample suggested that nitrite plays a role in regulating the distribution of absorbed excitation energy between the two photosystems. We propose, for the first time, that the removal of loosely bound nitrite leads to migration of light‐harvesting complex II back to the PS II, and thus the mode of binding of nitrite regulates the extent of migration of antenna molecules between the two photosystems.

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“…The simultaneous stepwise shift in the peak position of the B-band indicated, however, that S 3 Q B − charge recombination is more resistant to Cu (II). Nitrite, but not formate, fluoride or nitrate anions, inhibited PSII in spinach thylakoids, probably at the donor side (Sahay et al, 2006).…”

mentioning

confidence: 88%

Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

et al. 2015

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A thermoluminescence study of the effects of nitrite on photosystem II in spinach thylakoids

Cited by 6 publications

References 29 publications

The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803

The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803

Relation between the mode of binding of nitrite and the energy distribution between the two photosystems

Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

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