1
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Tanigawa K, Yuchen Q, Katsuhama N, Sakoda K, Wakabayashi Y, Tanaka Y, Sage R, Lawson T, Yamori W. C 4 monocots and C 4 dicots exhibit rapid photosynthetic induction response in contrast to C 3 plants. PHYSIOLOGIA PLANTARUM 2024; 176:e14431. [PMID: 39041649 DOI: 10.1111/ppl.14431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/10/2024] [Accepted: 07/01/2024] [Indexed: 07/24/2024]
Abstract
Considering the prevalence of ever-changing conditions in the natural world, investigation of photosynthetic responses in C4 plants under fluctuating light is needed. Here, we studied the effect of dynamic illumination on photosynthesis in totally 10 C3, C3-C4 intermediate, C4-like and C4 dicots and monocots at CO2 concentrations of 400 and 800 μmol mol-1. C4 and C4-like plants had faster photosynthetic induction and light-induced stomatal dynamics than C3 plants at 400 μmol mol-1, but not at 800 μmol mol-1 CO2, at which the CO2 supply rarely limits photosynthesis. C4 and C4-like plants had a higher water use efficiency than C3 plants at both CO2 concentrations. There were positive correlations between photosynthetic induction and light-induced stomatal response, together with CO2 compensation point, which was a parameter of the CO2-concentrating mechanism of C4 photosynthesis. These results clearly show that C4 photosynthesis in both monocots and dicots adapts to fluctuating light conditions more efficiently than C3 photosynthesis. The rapid photosynthetic induction response in C4 plants can be attributed to the rapid stomatal dynamics, the CO2-concentrating mechanism or both.
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Affiliation(s)
- Keiichiro Tanigawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Qu Yuchen
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoya Katsuhama
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazuma Sakoda
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Tokyo, Japan
| | - Yu Wakabayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yu Tanaka
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama, Japan
| | - Rowan Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK
| | - Wataru Yamori
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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2
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Zhang Y, Kaiser E, Dutta S, Sharkey TD, Marcelis LFM, Li T. Short-term salt stress reduces photosynthetic oscillations under triose phosphate utilization limitation in tomato. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2994-3008. [PMID: 38436737 DOI: 10.1093/jxb/erae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/02/2024] [Indexed: 03/05/2024]
Abstract
Triose phosphate utilization (TPU) limitation is one of the three biochemical limitations of photosynthetic CO2 assimilation rate in C3 plants. Under TPU limitation, abrupt and large transitions in light intensity cause damped oscillations in photosynthesis. When plants are salt-stressed, photosynthesis is often down-regulated particularly under dynamic light intensity, but how salt stress affects TPU-related dynamic photosynthesis is still unknown. To elucidate this, tomato (Solanum lycopersicum) was grown with and without sodium chloride (NaCl, 100 mM) stress for 13 d. Under high CO2 partial pressure, rapid increases in light intensity caused profound photosynthetic oscillations. Salt stress reduced photosynthetic oscillations in leaves initially under both low- and high-light conditions and reduced the duration of oscillations by about 2 min. Besides, salt stress increased the threshold for CO2 partial pressure at which oscillations occurred. Salt stress increased TPU capacity without affecting Rubisco carboxylation and electron transport capacity, indicating the up-regulation of end-product synthesis capacity in photosynthesis. Thus salt stress may reduce photosynthetic oscillations by decreasing leaf internal CO2 partial pressure and/or increasing TPU capacity. Our results provide new insights into how salt stress modulates dynamic photosynthesis as controlled by CO2 availability and end-product synthesis.
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Affiliation(s)
- Yuqi Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Elias Kaiser
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University, Wageningen, the Netherlands
| | - Satadal Dutta
- Department of Precision and Microsystems Engineering, Faculty of 3ME, TU Delft, Delft, the Netherlands
| | - Thomas D Sharkey
- MSU-DOE Plant Research Laboratory, East Lansing, MI 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA
| | - Leo F M Marcelis
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University, Wageningen, the Netherlands
| | - Tao Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
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3
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Ermakova M, Woodford R, Taylor Z, Furbank RT, Belide S, von Caemmerer S. Faster induction of photosynthesis increases biomass and grain yield in glasshouse-grown transgenic Sorghum bicolor overexpressing Rieske FeS. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:1206-1216. [PMID: 36789455 DOI: 10.1111/pbi.14030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 02/08/2023] [Indexed: 05/27/2023]
Abstract
Sorghum is one of the most important crops providing food and feed in many of the world's harsher environments. Sorghum utilizes the C4 pathway of photosynthesis in which a biochemical carbon-concentrating mechanism results in high CO2 assimilation rates. Overexpressing the Rieske FeS subunit of the Cytochrome b6 f complex was previously shown to increase the rate of photosynthetic electron transport and stimulate CO2 assimilation in the model C4 plant Setaria viridis. To test whether productivity of C4 crops could be improved by Rieske overexpression, we created transgenic Sorghum bicolor Tx430 plants with increased Rieske content. The transgenic plants showed no marked changes in abundances of other photosynthetic proteins or chlorophyll content. The steady-state rates of electron transport and CO2 assimilation did not differ between the plants with increased Rieske abundance and control plants, suggesting that Cytochrome b6 f is not the only factor limiting electron transport in sorghum at high light and high CO2 . However, faster responses of non-photochemical quenching as well as an elevated quantum yield of Photosystem II and an increased CO2 assimilation rate were observed from the plants overexpressing Rieske during the photosynthetic induction, a process of activation of photosynthesis upon the dark-light transition. As a consequence, sorghum with increased Rieske content produced more biomass and grain when grown in glasshouse conditions. Our results indicate that increasing Rieske content has potential to boost productivity of sorghum and other C4 crops by improving the efficiency of light utilization and conversion to biomass through the faster induction of photosynthesis.
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Affiliation(s)
- Maria Ermakova
- Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, ACT, Australia
- School of Biological Sciences, Monash University, Melbourne, Vic, Australia
| | - Russell Woodford
- Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Zachary Taylor
- Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, ACT, Australia
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Brandenburg, Germany
| | - Robert T Furbank
- Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | | | - Susanne von Caemmerer
- Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, ACT, Australia
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4
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Zheng T, Yu Y, Kang H. Short-term elevated temperature and CO 2 promote photosynthetic induction in the C 3 plant Glycine max, but not in the C 4 plant Amaranthus tricolor. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:995-1007. [PMID: 35908799 DOI: 10.1071/fp21363] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
The continuous increases of atmospheric temperature and CO2 concentration will impact global photosynthesis. However, there are few studies considering the interaction of elevated temperature (eT) and elevated CO2 (eCO2 ) on dynamic photosynthesis, particularly for C4 species. We examine dynamic photosynthesis under four different temperature and [CO2 ] treatments: (1) 400ppm×28°C (CT); (2) 400ppm×33°C (CT+); (3) 800ppm×28°C (C+T); and (4) 800ppm×33°C (C+T+). In Glycine max L., the time required to reach 50% (T 50%A ) and 90% (T 90%A ) of full photosynthetic induction was smaller under the CT+, C+T, and C+T+ treatments than those under the CT treatment. In Amaranthus tricolor L., however, neither T 50%A nor T 90%A was not significantly affected by eT or eCO2 . In comparison with the CT treatment, the achieved carbon gain was increased by 58.3% (CT+), 112% (C+T), and 136.6% (C+T+) in G. max and was increased by 17.1% (CT+), 2.6% (C+T) and 56.9% (C+T+) in A. tricolor . The increases of achieved carbon gain in G. max were attributable to both improved photosynthetic induction efficiency (IE) and enhanced steady-state photosynthesis, whereas those in A. tricolor were attributable to enhanced steady-state photosynthesis.
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Affiliation(s)
- Tianyu Zheng
- Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
| | - Yuan Yu
- Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
| | - Huixing Kang
- Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
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5
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Wang Y, Chan KX, Long SP. Towards a dynamic photosynthesis model to guide yield improvement in C4 crops. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:343-359. [PMID: 34087011 PMCID: PMC9291162 DOI: 10.1111/tpj.15365] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 05/22/2023]
Abstract
The most productive C4 food and biofuel crops, such as Saccharum officinarum (sugarcane), Sorghum bicolor (sorghum) and Zea mays (maize), all use NADP-ME-type C4 photosynthesis. Despite high productivities, these crops fall well short of the theoretical maximum solar conversion efficiency of 6%. Understanding the basis of these inefficiencies is key for bioengineering and breeding strategies to increase the sustainable productivity of these major C4 crops. Photosynthesis is studied predominantly at steady state in saturating light. In field stands of these crops light is continually changing, and often with rapid fluctuations. Although light may change in a second, the adjustment of photosynthesis may take many minutes, leading to inefficiencies. We measured the rates of CO2 uptake and stomatal conductance of maize, sorghum and sugarcane under fluctuating light regimes. The gas exchange results were combined with a new dynamic photosynthesis model to infer the limiting factors under non-steady-state conditions. The dynamic photosynthesis model was developed from an existing C4 metabolic model for maize and extended to include: (i) post-translational regulation of key photosynthetic enzymes and their temperature responses; (ii) dynamic stomatal conductance; and (iii) leaf energy balance. Testing the model outputs against measured rates of leaf CO2 uptake and stomatal conductance in the three C4 crops indicated that Rubisco activase, the pyruvate phosphate dikinase regulatory protein and stomatal conductance are the major limitations to the efficiency of NADP-ME-type C4 photosynthesis during dark-to-high light transitions. We propose that the level of influence of these limiting factors make them targets for bioengineering the improved photosynthetic efficiency of these key crops.
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Affiliation(s)
- Yu Wang
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Kher Xing Chan
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Stephen P. Long
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Departments of Plant Biology and of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Lancaster Environment CentreLancaster UniversityLancasterLA1 4YQUK
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6
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Zhang MM, Fan DY, Murakami K, Badger MR, Sun GY, Chow WS. Partially Dissecting Electron Fluxes in Both Photosystems in Spinach Leaf Disks during Photosynthetic Induction. PLANT & CELL PHYSIOLOGY 2019; 60:2206-2219. [PMID: 31271439 DOI: 10.1093/pcp/pcz114] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 05/29/2019] [Indexed: 06/09/2023]
Abstract
Photosynthetic induction, a gradual increase in photosynthetic rate on a transition from darkness or low light to high light, has ecological significance, impact on biomass accumulation in fluctuating light and relevance to photoprotection in strong light. However, the experimental quantification of the component electron fluxes in and around both photosystems during induction has been rare. Combining optimized chlorophyll fluorescence, the redox kinetics of P700 [primary electron donor in Photosystem I (PSI)] and membrane inlet mass spectrometry in the absence/presence of inhibitors/mediator, we partially estimated the components of electron fluxes in spinach leaf disks on transition from darkness to 1,000 �mol photons�m-2�s-1 for up to 10 min, obtaining the following findings: (i) the partitioning of energy between both photosystems did not change noticeably; (ii) in Photosystem II (PSII), the combined cyclic electron flow (CEF2) and charge recombination (CR2) to the ground state decreased gradually toward 0 in steady state; (iii) oxygen reduction by electrons from PSII, partly bypassing PSI, was small but measurable; (iv) cyclic electron flow around PSI (CEF1) peaked before becoming somewhat steady; (v) peak magnitudes of some of the electron fluxes, all probably photoprotective, were in the descending order: CEF1 > CEF2 + CR2 > chloroplast O2 uptake; and (vi) the chloroplast NADH dehydrogenase-like complex appeared to aid the antimycin A-sensitive CEF1. The results are important for fine-tuning in silico simulation of in vivo photosynthetic electron transport processes; such simulation is, in turn, necessary to probe partial processes in a complex network of interactions in response to environmental changes.
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Affiliation(s)
- Meng-Meng Zhang
- Department of Plant Physiology, College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Da-Yong Fan
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
- College of Forestry, Beijing Forestry University, Beijing, China
| | - Keach Murakami
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
- National Agriculture and Food Research Organization (NARO), Hokkaido Agricultural Research Center (HARC), Hitsujigaoka 1, Toyohira, Sapporo, Japan
| | - Murray R Badger
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Guang-Yu Sun
- Department of Plant Physiology, College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Wah Soon Chow
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Acton, ACT, Australia
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7
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Kubásek J, Urban O, Šantrůček J. C4 plants use fluctuating light less efficiently than do C3 plants: a study of growth, photosynthesis and carbon isotope discrimination. PHYSIOLOGIA PLANTARUM 2013; 149:528-39. [PMID: 23550566 DOI: 10.1111/ppl.12057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/21/2013] [Accepted: 03/24/2013] [Indexed: 05/12/2023]
Abstract
Plants in the field are commonly exposed to fluctuating light intensity, caused by variable cloud cover, self-shading of leaves in the canopy and/or leaf movement due to turbulence. In contrast to C3 plant species, only little is known about the effects of dynamic light (DL) on photosynthesis and growth in C4 plants. Two C4 and two C3 monocot and eudicot species were grown under steady light or DL conditions with equal sum of daily incident photon flux. We measured leaf gas exchange, plant growth and dry matter carbon isotope discrimination to infer CO2 bundle sheath leakiness in C4 plants. The growth of all species was reduced by DL, despite only small changes in steady-state gas exchange characteristics, and this effect was more pronounced in C4 than C3 species due to lower assimilation at light transitions. This was partially attributed to increased bundle sheath leakiness in C4 plants under the simulated lightfleck conditions. We hypothesize that DL leads to imbalances in the coordination of C4 and C3 cycles and increasing leakiness, thereby decreasing the quantum efficiency of photosynthesis. In addition to their other constraints, the inability of C4 plants to efficiently utilize fluctuating light likely contributes to their absence in such environments as forest understoreys.
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Affiliation(s)
- Jiří Kubásek
- Global Change Research Centre, Academy of Sciences of the Czech Republic, Brno, Czech Republic
- The University of South Bohemia, Faculty of Science, CZ-370 05, České Budějovice, Czech Republic
| | - Otmar Urban
- Global Change Research Centre, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Jiří Šantrůček
- The University of South Bohemia, Faculty of Science, CZ-370 05, České Budějovice, Czech Republic
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, CZ-370 05, České Budějovice, Czech Republic
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8
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Driever SM, Baker NR. The water-water cycle in leaves is not a major alternative electron sink for dissipation of excess excitation energy when CO(2) assimilation is restricted. PLANT, CELL & ENVIRONMENT 2011; 34:837-46. [PMID: 21332508 DOI: 10.1111/j.1365-3040.2011.02288.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Electron flux from water via photosystem II (PSII) and PSI to oxygen (water-water cycle) may provide a mechanism for dissipation of excess excitation energy in leaves when CO(2) assimilation is restricted. Mass spectrometry was used to measure O(2) uptake and evolution together with CO(2) uptake in leaves of French bean and maize at CO(2) concentrations saturating for photosynthesis and the CO(2) compensation point. In French bean at high CO(2) and low O(2) concentrations no significant water-water cycle activity was observed. At the CO(2) compensation point and 3% O(2) a low rate of water-water cycle activity was observed, which accounted for 30% of the linear electron flux from water. In maize leaves negligible water-water cycle activity was detected at the compensation point. During induction of photosynthesis in maize linear electron flux was considerably greater than CO(2) assimilation, but no significant water-water cycle activity was detected. Miscanthus × giganteus grown at chilling temperature also exhibited rates of linear electron transport considerably in excess of CO(2) assimilation; however, no significant water-water cycle activity was detected. Clearly the water-water cycle can operate in leaves under some conditions, but it does not act as a major sink for excess excitation energy when CO(2) assimilation is restricted.
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Affiliation(s)
- Steven M Driever
- Department of Biological Sciences, University of Essex, Essex, Colchester CO4 3SQ, UK
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9
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Stamatakis K, Tsimilli-Michael M, Papageorgiou GC. Fluorescence induction in the phycobilisome-containing cyanobacterium Synechococcus sp PCC 7942: Analysis of the slow fluorescence transient. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:766-72. [PMID: 17448439 DOI: 10.1016/j.bbabio.2007.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 02/02/2007] [Accepted: 02/07/2007] [Indexed: 11/22/2022]
Abstract
At room temperature, the chlorophyll (Chl) a fluorescence induction (FI) kinetics of plants, algae and cyanobacteria go through two maxima, P at approximately 0.2-1 and M at approximately 100-500 s, with a minimum S at approximately 2-10 s in between. Thus, the whole FI kinetic pattern comprises a fast OPS transient (with O denoting origin) and a slower SMT transient (with T denoting terminal state). Here, we examined the phenomenology and the etiology of the SMT transient of the phycobilisome (PBS)-containing cyanobacterium Synechococcus sp PCC 7942 by modifying PBS-->Photosystem (PS) II excitation transfer indirectly, either by blocking or by maximizing the PBS-->PS I excitation transfer. Blocking the PBS-->PS I excitation transfer route with N-ethyl-maleimide [NEM; A. N. Glazer, Y. Gindt, C. F. Chan, and K.Sauer, Photosynth. Research 40 (1994) 167-173] increases both the PBS excitation share of PS II and Chl a fluorescence. Maximizing it, on the other hand, by suspending cyanobacterial cells in hyper-osmotic media [G. C. Papageorgiou, A. Alygizaki-Zorba, Biochim. Biophys. Acta 1335 (1997) 1-4] diminishes both the PBS excitation share of PS II and Chl a fluorescence. Here, we show for the first time that, in either case, the slow SMT transient of FI disappears and is replaced by continuous P-->T fluorescence decay, reminiscent of the typical P-->T fluorescence decay of higher plants and algae. A similar P-->T decay was also displayed by DCMU-treated Synechococcus cells at 2 degrees C. To interpret this phenomenology, we assume that after dark adaptation cyanobacteria exist in a low fluorescence state (state 2) and transit to a high fluorescence state (state 1) when, upon light acclimation, PS I is forced to run faster than PS II. In these organisms, a state 2-->1 fluorescence increase plus electron transport-dependent dequenching processes dominate the SM rise and maximal fluorescence output is at M which lies above the P maximum of the fast FI transient. In contrast, dark-adapted plants and algae exist in state 1 and upon illumination they display an extended P-->T decay that sometimes is interrupted by a shallow SMT transient, with M below P. This decay is dominated by a state 1-->2 fluorescence lowering, as well as by electron transport-dependent quenching processes. When the regulation of the PBS-->PS I electronic excitation transfer is eliminated (as for example in hyper-osmotic suspensions, after NEM treatment and at low temperature), the FI pattern of Synechococcus becomes plant-like.
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biology, NCSR Demokritos, Aghia Paraskevi, Attikis 15310, Greece.
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10
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Measurements of the quantum yield of carbon assimilation and chlorophyll fluorescence for assessment of photosynthetic performance of crops in the field. ACTA ACUST UNITED AC 1997. [DOI: 10.1098/rstb.1989.0011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An apparatus is described for the rapid measurement in the field of the quantum yield of CO
2
assimilation, ø, and chlorophyll fluorescence kinetics from attached leaves exposed to ambient CO
2
concentrations. This apparatus was used to measure ø and the ratio of variable to maximal fluorescence, F
v
/F
M
, of fully expanded leaves of a maize crop in northeast Essex at monthly intervals throughout the growing season. The quantum yield of CO
2
assimilation and F
v
/F
M
increased from May to August and then decreased in September. A linear correlation between ø and F
v
/F
M
was observed for the leaves. The relations between light, temperature, the quantum yield of CO
2
assimilation and fluorescence emission kinetics of leaves of a maize crop during the early growing season were also examined. Decreases in ø associated with chilling temperatures and high light were observed and identified from analyses of fluorescence kinetics as being attributable to photoinhibitory damage of the photosynthetic apparatus. The possibility of using measurements of ø and fluorescence kinetics for screening the photosynthetic performance of crops is considered. Studies with winter rape demonstrated that changes in ø during the growing season were correlated with changes in the efficiency of light-energy conversion to dry matter by the crop.
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11
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Dietz KJ, Foyer C. The relationship between phosphate status and photosynthesis in leaves : Reversibility of the effects of phosphate deficiency on photosynthesis. PLANTA 1986; 167:376-81. [PMID: 24240307 DOI: 10.1007/bf00391342] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/1985] [Accepted: 10/28/1985] [Indexed: 05/28/2023]
Abstract
Spinach (Spinacia oleracea L.) and barley (Hordeum vulgare L.) were grown in hydroponic culture with varying levels of orthophosphate (Pi). When leaves were fed with 20 mmol·l(-1) Pi at low CO2 concentrations, a temporary increase of CO2 uptake was observed in Pi-deficient leaves but not in those from plants grown at 1 mmol·l(-1) Pi. At high concentrations of CO2 (at 21% or 2% O2) the Pi-induced stimulation of CO2 uptake was pronounced in the Pi-deficient leaves. The contents of phosphorylated metabolites in the leaves decreased as a result of Pi deficiency but were restored by Pi feeding. These results demonstrate that there is an appreciable capacity for rapid Pi uptake by leaf mesophyll cells and show that the effects of long-term phosphate deficiency on photosynthesis may be reversed (at least temporarily) within minutes by feeding with Pi.
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Affiliation(s)
- K J Dietz
- Institut für Botanik, Universität Würzburg, Lehrstuhl Botanik 1, Mittlerer Dallenbergweg 64, D-8700, Würzburg, Federal Republic of Germany
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12
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Furbank RT, Leegood RC. Carbon metabolism and gas exchange in leaves of Zea mays L. : Interaction between the C3 and C 4 pathways during photosynthetic induction. PLANTA 1984; 162:450-6. [PMID: 24253228 DOI: 10.1007/bf00393458] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/1984] [Accepted: 05/25/1984] [Indexed: 05/07/2023]
Abstract
The aim of this work was to investigate the mechanism of formation of triose phosphates and 3-phosphoglycerate during photosynthetic induction in leaves of Zea mays. Simultaneous measurements of gas exchange, chlorophyll a fluorescence and metabolite contents of maize leaves were made. Leaves illuminated in the absence of CO2 showed a build-up of triose phosphates during the first 2 min of illumination which was comparable to the build-up observed in the presence of CO2. Isolated mesophyll protoplasts, which lack the Calvin cycle, also showed a build-up of triose phosphates upon illumination. Leaves contained amounts of phosphoglycerate mutase and enolase adequate to account for the formation of triose phosphates and 3-phosphoglycerate from intermediates of the C4 cycle and their precursors.
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Affiliation(s)
- R T Furbank
- Research Institute for Photosynthesis, Department of Botany, University of Sheffield, S10 2TN, Sheffield, UK
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