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Yang QY, Wang XQ, Yang YJ, Huang W. Fluctuating light induces a significant photoinhibition of photosystem I in maize. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108426. [PMID: 38340689 DOI: 10.1016/j.plaphy.2024.108426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/19/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
In nature, light intensity usually fluctuates and a sudden shade-sun transition can induce photodamage to photosystem I (PSI) in many angiosperms. Photosynthetic regulation in fluctuating light (FL) has been studied extensively in C3 plants; however, little is known about how C4 plants cope FL to prevent PSI photoinhibition. We here compared photosynthetic responses to FL between maize (Zea mays, C4) and tomato (Solanum lycopersicum, C3) grown under full sunlight. Maize leaves had significantly higher cyclic electron flow (CEF) activity and lower photorespiration activity than tomato. Upon a sudden shade-sun transition, maize showed a significant stronger transient PSI over-reduction than tomato, resulting in a significant greater PSI photoinhibition in maize after FL treatment. During the first seconds upon shade-sun transition, CEF was stimulated in maize at a much higher extent than tomato, favoring the rapid formation of trans-thylakoid proton gradient (ΔpH), which was helped by a transient down-regulation of chloroplast ATP synthase activity. Therefore, modulation of ΔpH by regulation of CEF and chloroplast ATP synthase adjusted PSI redox state at donor side, which partially compensated for the deficiency of photorespiration. We propose that C4 plants use different photosynthetic strategies for coping with FL as compared with C3 plants.
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Affiliation(s)
- Qiu-Yan Yang
- School of Life Sciences, Shannxi Normal University, Xi'an, 710119, China; Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Xiao-Qian Wang
- School of Life Sciences, Shannxi Normal University, Xi'an, 710119, China
| | - Ying-Jie Yang
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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Schiphorst C, Koeman C, Caracciolo L, Staring K, Theeuwen TPJM, Driever SM, Harbinson J, Wientjes E. The effects of different daily irradiance profiles on Arabidopsis growth, with special attention to the role of PsbS. FRONTIERS IN PLANT SCIENCE 2023; 14:1070218. [PMID: 36968375 PMCID: PMC10035889 DOI: 10.3389/fpls.2023.1070218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
In nature, light is never constant, while in the controlled environments used for vertical farming, in vitro propagation, or plant production for scientific research, light intensity is often kept constant during the photoperiod. To investigate the effects on plant growth of varying irradiance during the photoperiod, we grew Arabidopsis thaliana under three irradiance profiles: a square-wave profile, a parabolic profile with gradually increasing and subsequently decreasing irradiance, and a regime comprised of rapid fluctuations in irradiance. The daily integral of irradiance was the same for all three treatments. Leaf area, plant growth rate, and biomass at time of harvest were compared. Plants grown under the parabolic profile had the highest growth rate and biomass. This could be explained by a higher average light-use efficiency for carbon dioxide fixation. Furthermore, we compared the growth of wild type plants with that of the PsbS-deficient mutant npq4. PsbS triggers the fast non-photochemical quenching process (qE) that protects PSII from photodamage during sudden increases in irradiance. Based mainly on field and greenhouse experiments, the current consensus is that npq4 mutants grow more slowly in fluctuating light. However, our data show that this is not the case for several forms of fluctuating light conditions under otherwise identical controlled-climate room conditions.
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Affiliation(s)
- Christo Schiphorst
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
| | - Cas Koeman
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
| | - Ludovico Caracciolo
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
| | - Koen Staring
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
| | | | - Steven M. Driever
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, Netherlands
| | - Jeremy Harbinson
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, Netherlands
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Photoinhibition of Photosystem I Induced by Different Intensities of Fluctuating Light Is Determined by the Kinetics of ∆pH Formation Rather Than Linear Electron Flow. Antioxidants (Basel) 2022; 11:antiox11122325. [PMID: 36552532 PMCID: PMC9774317 DOI: 10.3390/antiox11122325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 11/25/2022] Open
Abstract
Fluctuating light (FL) can cause the selective photoinhibition of photosystem I (PSI) in angiosperms. In nature, leaves usually experience FL conditions with the same low light and different high light intensities, but the effects of different FL conditions on PSI redox state and PSI photoinhibition are not well known. In this study, we found that PSI was highly reduced within the first 10 s after transition from 59 to 1809 μmol photons m-2 s-1 in tomato (Solanum lycopersicum). However, such transient PSI over-reduction was not observed by transitioning from 59 to 501 or 923 μmol photons m-2 s-1. Consequently, FL (59-1809) induced a significantly stronger PSI photoinhibition than FL (59-501) and FL (59-923). Compared with the proton gradient (∆pH) level after transition to high light for 60 s, tomato leaves almost formed a sufficient ∆pH after light transition for 10 s in FL (59-501) but did not in FL (59-923) or FL (59-1809). The difference in ∆pH between 10 s and 60 s was tightly correlated to the extent of PSI over-reduction and PSI photoinhibition induced by FL. Furthermore, the difference in PSI photoinhibition between (59-923) and FL (59-1809) was accompanied by the same level of linear electron flow. Therefore, PSI photoinhibition induced by different intensities of FL is more related to the kinetics of ∆pH formation rather than linear electron flow.
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Regulation of Chloroplast ATP Synthase Modulates Photoprotection in the CAM Plant Vanilla planifolia. Cells 2022; 11:cells11101647. [PMID: 35626684 PMCID: PMC9139848 DOI: 10.3390/cells11101647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/27/2022] Open
Abstract
Generally, regulation of cyclic electron flow (CEF) and chloroplast ATP synthase play key roles in photoprotection for photosystems I and II (PSI and PSII) in C3 and C4 plants, especially when CO2 assimilation is restricted. However, how CAM plants protect PSI and PSII when CO2 assimilation is restricted is largely known. In the present study, we measured PSI, PSII, and electrochromic shift signals in the CAM plant Vanilla planifolia. The quantum yields of PSI and PSII photochemistry largely decreased in the afternoon compared to in the morning, indicating that CO2 assimilation was strongly restricted in the afternoon. Meanwhile, non-photochemical quenching (NPQ) in PSII and the donor side limitation of PSI (Y(ND)) significantly increased to protect PSI and PSII. Under such conditions, proton gradient (∆pH) across the thylakoid membranes largely increased and CEF was slightly stimulated, indicating that the increased ∆pH was not caused by the regulation of CEF. In contrast, the activity of chloroplast ATP synthase (gH+) largely decreased in the afternoon. At a given proton flux, the decreasing gH+ increased ∆pH and thus contributed to the enhancement of NPQ and Y(ND). Therefore, in the CAM plant V. planifolia, the ∆pH-dependent photoprotective mechanism is mainly regulated by the regulation of gH+ rather than CEF when CO2 assimilation is restricted.
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Wang H, Wang XQ, Zeng ZL, Yu H, Huang W. Photosynthesis under fluctuating light in the CAM plant Vanilla planifolia. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 317:111207. [PMID: 35193751 DOI: 10.1016/j.plantsci.2022.111207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Photosynthetic induction after a sudden increase in illumination affects carbon gain. Photosynthetic dynamics under fluctuating light (FL) have been widely investigated in C3 and C4 plants but are little known in CAM plants. In our present study, the chlorophyll fluorescence, P700 redox state and electrochromic shift signals were measured to examine photosynthetic characteristics under FL in the CAM orchid Vanilla planifolia. The light use efficiency was maximized in the morning but was restricted in the afternoon, indicating that the pool of malic acid dried down in the afternoon. During photosynthetic induction in the morning, electron flow through photosystem I rapidly reached the 95% of the maximum value in 4-6 min, indicating that V. planifolia showed a fast photosynthetic induction when compared with C3 and C4 plants reported previously. Upon a sudden transition from dark to actinic light, a rapid re-oxidation of P700 was observed in V. planifolia, indicating the fast outflow of electrons from PSI to alternative electron acceptors, which was attributed to the O2 photo-reduction mediated by water-water cycle. The functioning of water-water cycle prevented photosystem I over-reduction after transitioning from low to high light and thus protected PSI under FL. In the afternoon, cyclic electron flow was stimulated under FL to fine-tune photosynthetic apparatus when photosynthetic CO2 was restricted. Therefore, water-water cycle cooperates with cyclic electron flow to regulate the photosynthesis under FL in the CAM orchid V. planifolia.
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Affiliation(s)
- Hui Wang
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, China
| | - Xiao-Qian Wang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Zhi-Lan Zeng
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huan Yu
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
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Zeng ZL, Sun H, Wang XQ, Zhang SB, Huang W. Regulation of Leaf Angle Protects Photosystem I under Fluctuating Light in Tobacco Young Leaves. Cells 2022; 11:252. [PMID: 35053368 PMCID: PMC8773500 DOI: 10.3390/cells11020252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 12/31/2021] [Accepted: 01/04/2022] [Indexed: 02/05/2023] Open
Abstract
Fluctuating light is a typical light condition in nature and can cause selective photodamage to photosystem I (PSI). The sensitivity of PSI to fluctuating light is influenced by the amplitude of low/high light intensity. Tobacco mature leaves are tended to be horizontal to maximize the light absorption and photosynthesis, but young leaves are usually vertical to diminish the light absorption. Therefore, we tested the hypothesis that such regulation of the leaf angle in young leaves might protect PSI against photoinhibition under fluctuating light. We found that, upon a sudden increase in illumination, PSI was over-reduced in extreme young leaves but was oxidized in mature leaves. After fluctuating light treatment, such PSI over-reduction aggravated PSI photoinhibition in young leaves. Furthermore, the leaf angle was tightly correlated to the extent of PSI photoinhibition induced by fluctuating light. Therefore, vertical young leaves are more susceptible to PSI photoinhibition than horizontal mature leaves when exposed to the same fluctuating light. In young leaves, the vertical leaf angle decreased the light absorption and thus lowered the amplitude of low/high light intensity. Therefore, the regulation of the leaf angle was found for the first time as an important strategy used by young leaves to protect PSI against photoinhibition under fluctuating light. To our knowledge, we show here new insight into the photoprotection for PSI under fluctuating light in nature.
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Affiliation(s)
- Zhi-Lan Zeng
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Qian Wang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
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Shi Q, Sun H, Timm S, Zhang S, Huang W. Photorespiration Alleviates Photoinhibition of Photosystem I under Fluctuating Light in Tomato. PLANTS 2022; 11:plants11020195. [PMID: 35050082 PMCID: PMC8780929 DOI: 10.3390/plants11020195] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/12/2022]
Abstract
Fluctuating light (FL) is a typical natural light stress that can cause photodamage to photosystem I (PSI). However, the effect of growth light on FL-induced PSI photoinhibition remains controversial. Plants grown under high light enhance photorespiration to sustain photosynthesis, but the contribution of photorespiration to PSI photoprotection under FL is largely unknown. In this study, we examined the photosynthetic performance under FL in tomato (Lycopersicon esculentum) plants grown under high light (HL-plants) and moderate light (ML-plants). After an abrupt increase in illumination, the over-reduction of PSI was lowered in HL-plants, resulting in a lower FL-induced PSI photoinhibition. HL-plants displayed higher capacities for CO2 fixation and photorespiration than ML-plants. Within the first 60 s after transition from low to high light, PSII electron transport was much higher in HL-plants, but the gross CO2 assimilation rate showed no significant difference between them. Therefore, upon a sudden increase in illumination, the difference in PSII electron transport between HL- and ML-plants was not attributed to the Calvin–Benson cycle but was caused by the change in photorespiration. These results indicated that the higher photorespiration in HL-plants enhanced the PSI electron sink downstream under FL, which mitigated the over-reduction of PSI and thus alleviated PSI photoinhibition under FL. Taking together, we here for the first time propose that photorespiration acts as a safety valve for PSI photoprotection under FL.
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Affiliation(s)
- Qi Shi
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Q.S.); (H.S.); (S.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Q.S.); (H.S.); (S.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Stefan Timm
- Plant Physiology Department, University of Rostock, D-18051 Rostock, Germany;
| | - Shibao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Q.S.); (H.S.); (S.Z.)
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Q.S.); (H.S.); (S.Z.)
- Correspondence:
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Diurnal Response of Photosystem I to Fluctuating Light Is Affected by Stomatal Conductance. Cells 2021; 10:cells10113128. [PMID: 34831351 PMCID: PMC8621556 DOI: 10.3390/cells10113128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 11/17/2022] Open
Abstract
Upon a sudden transition from low to high light, electrons transported from photosystem II (PSII) to PSI should be rapidly consumed by downstream sinks to avoid the over-reduction of PSI. However, the over-reduction of PSI under fluctuating light might be accelerated if primary metabolism is restricted by low stomatal conductance. To test this hypothesis, we measured the effect of diurnal changes in stomatal conductance on photosynthetic regulation under fluctuating light in tomato (Solanum lycopersicum) and common mulberry (Morus alba). Under conditions of high stomatal conductance, we observed PSI over-reduction within the first 10 s after transition from low to high light. Lower stomatal conductance limited the activity of the Calvin–Benson–Bassham cycle and aggravated PSI over-reduction within 10 s after the light transition. We also observed PSI over-reduction after transition from low to high light for 30 s at the low stomatal conductance typical of the late afternoon, indicating that low stomatal conductance extends the period of PSI over-reduction under fluctuating light. Therefore, diurnal changes in stomatal conductance significantly affect the PSI redox state under fluctuating light. Moreover, our analysis revealed an unexpected inhibition of cyclic electron flow by the severe over-reduction of PSI seen at low stomatal conductance. In conclusion, stomatal conductance can have a large effect on thylakoid reactions under fluctuating light.
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