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Saha S, Purkayastha S, K N, Ganguly S, Das S, Ganguly S, Sinha Mahapatra N, Bhattacharya K, Das D, Saha AK, Biswas T, Bhattacharyya PK, Bhattacharyya S. Rice ( Oryza sativa) alleviates photosynthesis and yield loss by limiting specific leaf weight under low light intensity. FUNCTIONAL PLANT BIOLOGY : FPB 2023; 50:267-276. [PMID: 36624487 DOI: 10.1071/fp22241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
The physiological mechanisms of shade tolerance and trait plasticity variations under shade remain poorly understood in rice (Oryza sativa L.). Twenty-five genotypes of rice were evaluated under open and shade conditions. Various parameters to identify variations in the plasticity of these traits in growth irradiance were measured. We found wide variations in specific leaf weight (SLW) and net assimilation rate measured at 400µmolm-2 s-1 photosynthetic photon flux density (PPFD; referred to as A 400 ) among the genotypes. Under shade, tolerant genotypes maintained a high rate of net photosynthesis by limiting specific leaf weight accompanied by increased intercellular CO2 concentration (C i ) compared with open-grown plants. On average, net photosynthesis was enhanced by 20% under shade, with a range of 2-30%. Increased accumulation of biomass under shade was observed, but it showed no correlation with photosynthetic plasticity. Chlorophyll a /b ratio also showed no association with photosynthetic rate and yield. Analysis of variance showed that 11%, 16%, and 37% of the total variance of A 400 , SLW, and C i were explained due to differences in growth irradiance. SLW and A 400 plasticity in growth irradiance was associated with yield loss alleviation with R 2 values of 0.37 and 0.16, respectively. Biomass accumulation was associated with yield loss alleviation under shade, but no correlation was observed between A 400 and leaf-N concentration. Thus, limiting specific leaf weight accompanied by increased C i rather than leaf nitrogen concentration might have allowed rice genotypes to maintain a high net photosynthesis rate per unit leaf area and high yield under shade.
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Affiliation(s)
- Shoumik Saha
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Shampa Purkayastha
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Nimitha K
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Sebantee Ganguly
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Subhadeep Das
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Shamba Ganguly
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Nilanjan Sinha Mahapatra
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Kriti Bhattacharya
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Dibakar Das
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Arup K Saha
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Tirthankar Biswas
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Prabir K Bhattacharyya
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
| | - Somnath Bhattacharyya
- Department of Genetics and Plant Breeding, Crop Research Unit, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, PIN 741252, West Bengal, India
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Sun Y, Huang F, Dykes GF, Liu LN. Diurnal Regulation of In Vivo Localization and CO 2-Fixing Activity of Carboxysomes in Synechococcus elongatus PCC 7942. Life (Basel) 2020; 10:E169. [PMID: 32872408 PMCID: PMC7555275 DOI: 10.3390/life10090169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
Carboxysomes are the specific CO2-fixing microcompartments in all cyanobacteria. Although it is known that the organization and subcellular localization of carboxysomes are dependent on external light conditions and are highly relevant to their functions, how carboxysome organization and function are actively orchestrated in natural diurnal cycles has remained elusive. Here, we explore the dynamic regulation of carboxysome positioning and carbon fixation in the model cyanobacterium Synechococcus elongatus PCC 7942 in response to diurnal light-dark cycles, using live-cell confocal imaging and Rubisco assays. We found that carboxysomes are prone to locate close to the central line along the short axis of the cell and exhibit a greater preference of polar distribution in the dark phase, coupled with a reduction in carbon fixation. Moreover, we show that deleting the gene encoding the circadian clock protein KaiA could lead to an increase in carboxysome numbers per cell and reduced portions of pole-located carboxysomes. Our study provides insight into the diurnal regulation of carbon fixation in cyanobacteria and the general cellular strategies of cyanobacteria living in natural habitat for environmental acclimation.
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Affiliation(s)
| | | | | | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; (Y.S.); (F.H.); (G.F.D.)
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Zhang Q, Peng S, Li Y. Increase rate of light-induced stomatal conductance is related to stomatal size in the genus Oryza. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5259-5269. [PMID: 31145797 PMCID: PMC6793446 DOI: 10.1093/jxb/erz267] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/22/2019] [Indexed: 05/02/2023]
Abstract
The rapid response of stomatal conductance (gs) to fluctuating irradiance is of great importance to maximize carbon assimilation while minimizing water loss. Smaller stomata have been proven to have a faster response rate than larger ones, but most of these studies have been conducted with forest trees. In the present study, the effects of stomatal anatomy on the kinetics of gs and photosynthesis were investigated in 16 Oryza genotypes. Light-induced stomatal opening includes an initial time lag (λ) followed by an exponential increase. Smaller stomata had a larger maximum stomatal conductance increase rate (Slmax) during the exponential increase phase, but showed a longer time lag and a lower initial stomatal conductance (gs,initial) at low light. Stomatal size was, surprisingly, negatively correlated with the time required to reach 50% of maximum gs and photosynthesis (T50%gs and T50%A), which was shown to be positively correlated with λ and negatively correlated with gs,initial. With a lower gs,initial and a larger λ, small stomata showed a faster decrease of intercellular CO2 concentration (Ci) during the induction process, which may have led to a slower apparent Rubisco activation rate. Therefore, smaller stomata do not always benefit photosynthesis as reported before; the influence of stomatal size on dynamic photosynthesis is also correlated with λ and gs,initial.
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Affiliation(s)
- Qiangqiang Zhang
- National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shaobing Peng
- National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
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Kaiser E, Morales A, Harbinson J. Fluctuating Light Takes Crop Photosynthesis on a Rollercoaster Ride. PLANT PHYSIOLOGY 2018; 176:977-989. [PMID: 29046421 PMCID: PMC5813579 DOI: 10.1104/pp.17.01250] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/16/2017] [Indexed: 05/18/2023]
Abstract
Crops are regularly exposed to frequent irradiance fluctuations, which decrease their integrated CO2 assimilation and affect their phenotype.
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Affiliation(s)
- Elias Kaiser
- Horticulture and Product Physiology Group, Wageningen University, 6700 AA Wageningen, The Netherlands
| | - Alejandro Morales
- Centre for Crop Systems Analysis, Wageningen University, 6700 AK Wageningen, The Netherlands
| | - Jeremy Harbinson
- Horticulture and Product Physiology Group, Wageningen University, 6700 AA Wageningen, The Netherlands
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Kaiser E, Morales A, Harbinson J, Heuvelink E, Prinzenberg AE, Marcelis LFM. Metabolic and diffusional limitations of photosynthesis in fluctuating irradiance in Arabidopsis thaliana. Sci Rep 2016; 6:31252. [PMID: 27502328 PMCID: PMC4977489 DOI: 10.1038/srep31252] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/11/2016] [Indexed: 11/09/2022] Open
Abstract
A better understanding of the metabolic and diffusional limitations of photosynthesis in fluctuating irradiance can help identify targets for improving crop yields. We used different genotypes of Arabidopsis thaliana to characterise the importance of Rubisco activase (Rca), stomatal conductance (gs), non-photochemical quenching of chlorophyll fluorescence (NPQ) and sucrose phosphate synthase (SPS) on photosynthesis in fluctuating irradiance. Leaf gas exchange and chlorophyll fluorescence were measured in leaves exposed to stepwise increases and decreases in irradiance. rwt43, which has a constitutively active Rubisco enzyme in different irradiance intensities (except in darkness), showed faster increases than the wildtype, Colombia-0, in photosynthesis rates after step increases in irradiance. rca-2, having decreased Rca concentration, showed lower rates of increase. In aba2-1, high gs increased the rate of change after stepwise irradiance increases, while in C24, low gs tended to decrease it. Differences in rates of change between Colombia-0 and plants with low levels of NPQ (npq1-2, npq4-1) or SPS (spsa1) were negligible. In Colombia-0, the regulation of Rubisco activation and of gs were therefore limiting for photosynthesis in fluctuating irradiance, while levels of NPQ or SPS were not. This suggests Rca and gs as targets for improvement of photosynthesis of plants in fluctuating irradiance.
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Affiliation(s)
- Elias Kaiser
- Horticulture and Product Physiology Group, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Alejandro Morales
- Centre for Crop Systems Analysis, Department of Plant Sciences, Wageningen University, PO Box 430, 6700 AK Wageningen, The Netherlands
| | - Jeremy Harbinson
- Horticulture and Product Physiology Group, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Ep Heuvelink
- Horticulture and Product Physiology Group, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Aina E Prinzenberg
- Horticulture and Product Physiology Group, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands.,Laboratory of Genetics, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Leo F M Marcelis
- Horticulture and Product Physiology Group, Department of Plant Sciences, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
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Scales JC, Parry MAJ, Salvucci ME. A non-radioactive method for measuring Rubisco activase activity in the presence of variable ATP: ADP ratios, including modifications for measuring the activity and activation state of Rubisco. PHOTOSYNTHESIS RESEARCH 2014; 119:355-65. [PMID: 24390640 PMCID: PMC3923112 DOI: 10.1007/s11120-013-9964-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/19/2013] [Indexed: 05/19/2023]
Abstract
Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyzes carboxylation of ribulose-1,5-bisphosphate, the first in a series of reactions leading to the incorporation of atmospheric CO₂ into biomass. Rubisco requires Rubisco activase (RCA), an AAA+ ATPase that reactivates Rubisco by remodelling the conformation of inhibitor-bound sites. RCA is regulated by the ratio of ADP:ATP, with the precise response potentiated by redox regulation of the alpha-isoform. Measuring the effects of ADP on the activation of Rubisco by RCA using the well-established photometric assay is problematic because of the adenine nucleotide requirement of 3-phosphoglycerate (3-PGA) kinase. Described here is a novel assay for measuring RCA activity in the presence of variable ratios of ADP:ATP. The assay couples the formation of 3-PGA from ribulose 1,5-bisphosphate and CO₂ to NADH oxidation through cofactor-dependent phosphoglycerate mutase, enolase, PEP carboxylase and malate dehydrogenase. The assay was used to determine the effects of Rubisco and RCA concentration and ADP:ATP ratio on RCA activity, and to measure the activation of a modified Rubisco by RCA. Variations of the basic assay were used to measure the activation state of Rubisco in leaf extracts and the activity of purified Rubisco. The assay can be automated for high-throughput processing by conducting the reactions in two stages.
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Affiliation(s)
- Joanna C. Scales
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Martin A. J. Parry
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Michael E. Salvucci
- Arid-Land Agricultural Research Center, U.S. Department of Agriculture-Agricultural Research Service, 21881 N. Cardon Lane, Maricopa, AZ 85138 USA
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Carmo-Silva AE, Salvucci ME. The activity of Rubisco's molecular chaperone, Rubisco activase, in leaf extracts. PHOTOSYNTHESIS RESEARCH 2011; 108:143-55. [PMID: 21728079 DOI: 10.1007/s11120-011-9667-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 06/18/2011] [Indexed: 05/19/2023]
Abstract
Rubisco frequently undergoes unproductive interactions with its sugar-phosphate substrate that stabilize active sites in an inactive conformation. Restoring catalytic competence to these sites requires the "molecular chiropractic" activity of Rubisco activase (activase). To make the study of activase more routine and physiologically relevant, an assay was devised for measuring activase activity in leaf extracts based on the ATP-dependent activation of inactive Rubisco. Control experiments with an Arabidopsis activase-deficient mutant confirmed that the rate of Rubisco activation was dependent on the concentration of activase in the extracts. Activase catalyzed Rubisco activation at rates equivalent to 9-14% catalytic sites per min in desalted extracts of Arabidopsis, camelina, tobacco, cotton, and wheat. Faster rates were observed in a transgenic line of Arabidopsis that expresses only the β-isoform of activase, whereas no activity was detected in a line that expresses only the α-isoform. Activase activity was also low or undetectable in rice, maize, and Chlamydomonas, revealing differences in the stability of the enzyme in different species. These differences are discussed in terms of the ability of activase subunits to remain associated or to reassociate into active oligomers when the stromal milieu is diluted by extraction. Finally, the temperature response of activase activity in leaf extracts differed for Arabidopsis, camelina, tobacco, and cotton, corresponding to the respective temperature responses of photosynthesis for each species. These results confirmed the exceptional thermal lability of activase at physiological ratios of activase to Rubisco.
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Affiliation(s)
- A Elizabete Carmo-Silva
- U.S. Department of Agriculture, Agricultural Research Service, Arid-Land Agricultural Research Center, 21881 N Cardon Lane, Maricopa, AZ 85138, USA.
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Jung KH, Dardick C, Bartley LE, Cao P, Phetsom J, Canlas P, Seo YS, Shultz M, Ouyang S, Yuan Q, Frank BC, Ly E, Zheng L, Jia Y, Hsia AP, An K, Chou HH, Rocke D, Lee GC, Schnable PS, An G, Buell CR, Ronald PC. Refinement of light-responsive transcript lists using rice oligonucleotide arrays: evaluation of gene-redundancy. PLoS One 2008; 3:e3337. [PMID: 18836531 PMCID: PMC2556097 DOI: 10.1371/journal.pone.0003337] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 09/11/2008] [Indexed: 01/04/2023] Open
Abstract
Studies of gene function are often hampered by gene-redundancy, especially in organisms with large genomes such as rice (Oryza sativa). We present an approach for using transcriptomics data to focus functional studies and address redundancy. To this end, we have constructed and validated an inexpensive and publicly available rice oligonucleotide near-whole genome array, called the rice NSF45K array. We generated expression profiles for light- vs. dark-grown rice leaf tissue and validated the biological significance of the data by analyzing sources of variation and confirming expression trends with reverse transcription polymerase chain reaction. We examined trends in the data by evaluating enrichment of gene ontology terms at multiple false discovery rate thresholds. To compare data generated with the NSF45K array with published results, we developed publicly available, web-based tools (www.ricearray.org). The Oligo and EST Anatomy Viewer enables visualization of EST-based expression profiling data for all genes on the array. The Rice Multi-platform Microarray Search Tool facilitates comparison of gene expression profiles across multiple rice microarray platforms. Finally, we incorporated gene expression and biochemical pathway data to reduce the number of candidate gene products putatively participating in the eight steps of the photorespiration pathway from 52 to 10, based on expression levels of putatively functionally redundant genes. We confirmed the efficacy of this method to cope with redundancy by correctly predicting participation in photorespiration of a gene with five paralogs. Applying these methods will accelerate rice functional genomics.
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Affiliation(s)
- Ki-Hong Jung
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Christopher Dardick
- Appalachian Fruit Research Station, USDA-ARS, Kearneysville, West Virginia, United States of America
| | - Laura E. Bartley
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Peijian Cao
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Jirapa Phetsom
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Patrick Canlas
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Young-Su Seo
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Michael Shultz
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Shu Ouyang
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Qiaoping Yuan
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Bryan C. Frank
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Eugene Ly
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Li Zheng
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Yi Jia
- Center for Plant Genomics, Iowa State University, Ames, Iowa, United States of America
| | - An-Ping Hsia
- Center for Plant Genomics, Iowa State University, Ames, Iowa, United States of America
| | - Kyungsook An
- Functional Genomic Center, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hui-Hsien Chou
- Center for Plant Genomics, Iowa State University, Ames, Iowa, United States of America
| | - David Rocke
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
| | - Geun Cheol Lee
- College of Business Administration, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Patrick S. Schnable
- Center for Plant Genomics, Iowa State University, Ames, Iowa, United States of America
| | - Gynheung An
- Functional Genomic Center, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - C. Robin Buell
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Pamela C. Ronald
- Department of Plant Pathology, University of California Davis, Davis, California, United States of America
- * E-mail:
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Zhang N, Kallis RP, Ewy RG, Portis AR. Light modulation of Rubisco in Arabidopsis requires a capacity for redox regulation of the larger Rubisco activase isoform. Proc Natl Acad Sci U S A 2002; 99:3330-4. [PMID: 11854454 PMCID: PMC122518 DOI: 10.1073/pnas.042529999] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The light activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in vivo requires the presence of Rubisco activase, a nuclear-encoded chloroplast protein that consists of two isoforms arising from alternative splicing in most plants. We examined the function of each isoform by characterizing Rubisco activation in transgenic Arabidopsis plants that express only one or both isoforms, as compared with the wild type. In plants expressing only the shorter isoform, Rubisco activity was as high as in the wild type under saturating light, but the activity was not down-regulated at intensities limiting for photosynthesis. In contrast, in plants expressing only the longer isoform, Rubisco activity was down-regulated at limiting light, but the activity was slightly lower and increased much more slowly at saturating light intensities as compared with the wild type. Light regulation of Rubisco similar to that in the wild-type plants was observed in the progeny of a genetic cross of these two transformants in which both isoforms were again present. When the capacity to redox regulate the activity of the larger activase isoform was eliminated by replacement of the critical cysteine residues in the carboxyl-terminal extension unique to this isoform, Rubisco activity in saturating light was similar to the wild type, but the ability of the larger isoform to down-regulate Rubisco activity at limiting light intensities in transgenic plants was almost abolished. These results indicate that the light modulation of Rubisco under limiting light is mainly due to the ability to regulate the activity of Rubisco activase by redox changes in the stroma.
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Affiliation(s)
- Ning Zhang
- Program in Physiological and Molecular Plant Biology, Department of Plant Biology, United States Department of Agriculture, Agricultural Research Service, 190 Madigan Laboratories, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Sage RF, Cen YP, Li M. The activation state of Rubisco directly limits photosynthesis at low CO(2) and low O(2) partial pressures. PHOTOSYNTHESIS RESEARCH 2002; 71:241-50. [PMID: 16228135 DOI: 10.1023/a:1015510005536] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Using gas exchange, enzyme assays, and theoretical modeling of photosynthetic responses to light and CO(2), we investigated whether decarbamylation of the active site of Rubisco at low CO(2) and low light leads to a condition where the activation state of Rubisco directly limits the rate of net CO(2) assimilation. Photosynthetic limitation by a reduction in the activation state of Rubisco would be indicated as a decline in the initial slope of the photosynthetic CO(2) response relative to what is predicted using theoretical models. In bean (Phaseolus vulgaris) and oat (Avena sativa), we saw no discrepancy between predicted and observed initial slope values at 200 and 400 mbar O(2), indicating no limitation by the carbamylation state of Rubisco. At 30 mbar O(2) and light saturation, we also saw no discrepancy between predicted and observed initial slope values; however, at subsaturating light intensity, our observed initial slope values were less than the modeled initial slope values that corresponded to an RuBP regeneration limitation. Moreover, significant reduction of the Rubisco activation state occurred in both species at 30 mbar O(2) and 30 mubar CO(2). When the model was reprogrammed to account for observed levels of Rubisco deactivation, the predicted and measured initial slope values at low O(2) and low PPFD were similar, indicating the reduction in carbamylation state accounted for the discrepancy. We interpret this as evidence for a direct limitation of the carbamylation state of Rubisco, probably because of a CO(2) limitation for carbamate formation. This limitation was only observed at intercellular CO(2) levels below what is encountered in vivo. At physiologically relevant CO(2) levels in situ, the leaves maintained sufficient Rubisco activity to avoid cabamylation state limitations in the steady state.
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Affiliation(s)
- Rowan F Sage
- Department of Botany, University of Toronto, Toronto, Ontario, M5S 3B2, Canada,
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Meng Q, Siebke K, Lippert P, Baur B, Mukherjee U, Weis E. Sink-source transition in tobacco leaves visualized using chlorophyll fluorescence imaging. THE NEW PHYTOLOGIST 2001; 151:585-595. [PMID: 33853257 DOI: 10.1046/j.0028-646x.2001.00224.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
• The sink-source transition of developing Nicotiana tabacum (tobacco) leaves was studied here using chlorophyll fluorescence imaging. • In accordance with leaf development, the quantum efficiency of PSII, showed a steep gradient across the leaf with increasing values towards the tip. • The linear electron transport rate (ETR) saturated at higher CO2 concentrations in the younger, than in the mature, part of the leaf, probably due to a lower Rubisco activity or a higher CO2 diffusion resistance. • The induction of ETR at CO2 concentrations near the compensation point after long-term dark adaptation of the young leaf, showed distinct responses; ETR rose rapidly in the basal but more slowly in the apical regions. There was a correlation between fast induction and carbohydrate import, as measured by 14 C-translocation. In the basal regions, larger pools of metabolic intermediates are expected due to imported carbohydrates. These might be used in the Calvin cycle directly after dark-light transition providing the electron acceptors for the faster induction of ETR. Additionally, a higher mitochondrial respiration can provide CO2 for the Calvin cycle in these regions.
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Affiliation(s)
- Qingwei Meng
- Institut für Botanik, Universität Münster Schlossgarten 3, D-48149 Münster, Germany; Present address: College of Life Science, Shandong Agricultural University, Taian, Shandong Province, 271018, PR China
| | | | - Peter Lippert
- Institut für Botanik, Universität Münster Schlossgarten 3, D-48149 Münster, Germany; Present address: College of Life Science, Shandong Agricultural University, Taian, Shandong Province, 271018, PR China
| | - Bernhard Baur
- Institut für Botanik, Universität Münster Schlossgarten 3, D-48149 Münster, Germany; Present address: College of Life Science, Shandong Agricultural University, Taian, Shandong Province, 271018, PR China
| | - Ute Mukherjee
- Institut für Botanik, Universität Münster Schlossgarten 3, D-48149 Münster, Germany; Present address: College of Life Science, Shandong Agricultural University, Taian, Shandong Province, 271018, PR China
| | - Engelbert Weis
- Institut für Botanik, Universität Münster Schlossgarten 3, D-48149 Münster, Germany; Present address: College of Life Science, Shandong Agricultural University, Taian, Shandong Province, 271018, PR China
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Salvucci ME, Ogren WL. The mechanism of Rubisco activase: Insights from studies of the properties and structure of the enzyme. PHOTOSYNTHESIS RESEARCH 1996; 47:1-11. [PMID: 24301702 DOI: 10.1007/bf00017748] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/1995] [Accepted: 10/27/1995] [Indexed: 06/02/2023]
Abstract
Rubisco, the primary carboxylating enzyme in photosynthesis, must be activated to catalyze CO2 fixation. The concept of an 'activase', a specific protein for activating Rubisco, was first introduced in 1985 based largely on biochemical and genetic studies of a high CO2-requiring mutant of Arabidopsis (Salvucci et al. (1985) Photosynth Res 7: 193-201). Over the past ten years, details about the occurrence, structure, and properties of Rubisco activase have been elucidated. However, the mechanism of action of Rubisco activase remains elusive. This review discusses the need for and function of Rubisco activase and summarizes information about the properties and structure of Rubisco activase. The information is evaluated in the context of the mechanism of Rubisco activase.
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Affiliation(s)
- M E Salvucci
- Western Cotton Research Laboratory, United States Department of Agriculture-Agricultural Research Service, 4135 E. Broadway Road, 85040-8830, Phoenix, AZ
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Sassenrath-Cole GF, Pearcy RW. Regulation of Photosynthetic Induction State by the Magnitude and Duration of Low Light Exposure. PLANT PHYSIOLOGY 1994; 105:1115-1123. [PMID: 12232269 PMCID: PMC159439 DOI: 10.1104/pp.105.4.1115] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This study was undertaken to examine the dependence of the regulatory enzymes of photosynthetic induction on photon flux density (PFD) exposure in soybean (Glycine max L.). The induction state varies as a function of both the magnitude and duration of the PFD levels experienced prior to an increase in PFD. The photosynthetic induction state results from the combined activity of separate processes that each in turn depend on prior PFD environment in different ways. Direct measurement of enzyme activities coupled with determination of in situ metabolite pool sizes indicated that the fast-induction component was associated with the activation state of stromal fructose-1,6-bisphosphatase (FBPase, EC 3.1.3.11) and showed rapid deactivation in the dark and at low PFD. The fast-induction component was activated at low PFD levels, around 70 [mu]mol photons m-2 s-1. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 2.7.1.19) deactivated very slowly in the dark and required higher PFD for activation. Both enzymes saturated at lower PFD than did photosynthesis, around 400 [mu]mol photons m-2 s-1. Ribulose-5-phosphate kinase (EC 2.7.1.19) appeared never to be limiting to photosynthesis, and saturated at much lower PFD than either FBPase or Rubisco. Determination of photosynthetic metabolite pool sizes from leaves at different positions within a soybean canopy showed a limitation to carbon uptake at the stromal FBPase and possibly the sedoheptulose-1,7-bisphosphatase (EC 3.1.3.37) in shade leaves upon initial illumination at saturating PFD levels.
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Masle J, Hudson GS, Badger MR. Effects of Ambient CO2 Concentration on Growth and Nitrogen Use in Tobacco (Nicotiana tabacum) Plants Transformed with an Antisense Gene to the Small Subunit of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase. PLANT PHYSIOLOGY 1993; 103:1075-1088. [PMID: 12232002 PMCID: PMC159092 DOI: 10.1104/pp.103.4.1075] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Growth of the R1 progeny of a tobacco plant (Nicotiana tabacum) transformed with an antisense gene to the small subunit of ribulose-1,5-carboxylase/oxygenase (Rubisco) was analyzed under 330 and 930 [mu]bar of CO2, at an irradiance of 1000 [mu]mol quanta m-2 s-1. Rubisco activity was reduced to 30 to 50% and 13 to 18% of that in the wild type when one and two copies of the antisense gene, respectively, were present in the genome, whereas null plants and wild-type plants had similar phenotypes. At 330 [mu]bar of CO2 all antisense plants were smaller than the wild type. There was no indication that Rubisco is present in excess in the wild type with respect to growth under high light. Raising ambient CO2 pressure to 930 [mu]bar caused plants with one copy of the DNA transferred from plasmid to plant genome to achieve the same size as the wild type at 330 [mu]bar, but plants with two copies remained smaller. Differences in final size were due mostly to early differences in relative rate of leaf area expansion (m2 m-2 d-1) or of biomass accumulation (g g-1 d-1): within less than 2 weeks after germination relative growth rates reached a steady-state value similar for all plants. Plants with greater carboxylation rates were characterized by a higher ratio of leaf carbon to leaf area, and at later stages, they were characterized also by a relatively greater allocation of structural and nonstructural carbon to roots versus leaves. However, these changes per se did not appear to be causing the long-term insensitivity of relative growth rates to variations in carboxylation rate. Nor was this insensitivity due to feedback inhibition of photosynthesis in leaves grown at high partial pressure of CO2 in the air (pa) or with high Rubisco activity, even when the amount of starch approached 40% of leaf dry weight. We propose that other intrinsic rate-limiting processes that are independent of carbohydrate supply were involved. Under plentiful nitrogen supply, reduction in the amount of nitrogen invested in Rubisco was more than compensated for by an increase in leaf nitrate. Nitrogen content of organic matter, excluding Rubisco, was unaffected by the antisense gene. In contrast, it was systematically lower at elevated pa than at normal pa. Combined with the positive effects of pa on growth, this resulted in the single-dose antisense plants growing as fast at 930 [mu]bar of CO2 as the wild-type plants at 330 [mu]bar of CO2 but at a lower organic nitrogen cost.
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Affiliation(s)
- J. Masle
- Plant Environmental Biology Group and Cooperative Research Centre for Plant Science, Research School of Biological Sciences, Institute of Advanced Studies, Australian National University, GPO Box 475, Canberra, ACT 2601, Australia
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Pilgrim ML, McClung CR. Differential Involvement of the Circadian Clock in the Expression of Genes Required for Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Synthesis, Assembly, and Activation in Arabidopsis thaliana. PLANT PHYSIOLOGY 1993; 103:553-564. [PMID: 12231961 PMCID: PMC159015 DOI: 10.1104/pp.103.2.553] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We have investigated the role of the circadian clock in the regulation of expression of genes required for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) synthesis, assembly, and activation. Circadian oscillations in RCA (the gene encoding Rubisco activase) and RBCS (the gene encoding Rubisco small subunit) mRNA accumulation, with peak abundance occurring soon after dawn, occur in Arabidopsis thaliana grown in a light-dark (LD) photoperiod. These oscillations persist in plants that have been transferred from LD to either continuous darkness (DD) or continuous light (LL). In contrast, CPN60[alpha] (the gene encoding [alpha]-chaperonin) and CPN60[beta] (the gene encoding [beta]-chaperonin) mRNA abundance oscillates in a diurnal, but not in a circadian, fashion. Although rapid damping of the circadian oscillation in RCA mRNA abundance is observed in Arabidopsis that have been grown in LD and then transferred to DD for 2 d, the circadian oscillations in RCA and RBCS mRNA abundance persist for at least five continuous cycles in LL, demonstrating the robustness of the circadian oscillator.
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Affiliation(s)
- M. L. Pilgrim
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755-3576
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Mott KA, Woodrow IE. Effects of O2 and CO2 on Nonsteady-State Photosynthesis (Further Evidence for Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Limitation). PLANT PHYSIOLOGY 1993; 102:859-866. [PMID: 12231872 PMCID: PMC158857 DOI: 10.1104/pp.102.3.859] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The effects of CO2 and O2 on nonsteady-state photosynthesis following an increase in photosynthetic photon flux density (PPFD) were examined in Spinacia oleracea to investigate the hypotheses that (a) a slow exponential phase (the ribulose-1,5-bisphosphate carboxylase/oxygenase [Rubisco] phase) of nonsteady-state photosynthesis is primarily limited by Rubisco activity and (b) Rubisco activation involves two sequential, light-dependent processes as described in a previous study (I.E. Woodrow, K.A. Mott [1992] Plant Physiol 99: 298-303). Photosynthesis was found to be sensitive to O2 during the Rubisco phase in the approach of photosynthesis to steady state. Analyses of this sensitivity to O2 showed that the control coefficient for Rubisco was approximately equal to 1 during this phase, suggesting that Rubisco was the primary limitation to photosynthesis. O2 had almost no effect on the kinetics (described using a relaxation time, [tau] of the Rubisco phase for leaves starting in darkness or for leaves starting in low PPFD, but [tau] was substantially higher in the former case. CO2 was found to affect both the rate of photosynthesis and the magnitude of [tau] for the Rubisco phase. The [tau] value for the Rubisco phase was found to be negatively correlated with intercellular CO2 concentration (ci), and leaves starting in darkness had higher values of [tau] at any ci than leaves starting in low PPFD. The effects of CO2 and O2 on the Rubisco phase are consistent with the existence of two sequential, light-dependent processes in the activation of Rubisco if neither process is sensitive to O2 and only the second process is sensitive to CO2. The implications of the data for the mechanism of Rubisco activation and for the effects of stomatal conductance on nonsteady-state photosynthesis are discussed.
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Affiliation(s)
- K. A. Mott
- Biology Department, Utah State University, Logan, Utah 84322-5303 (K.A.M.)
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Woodrow IE, Mott KA. Biphasic Activation of Ribulose Bisphosphate Carboxylase in Spinach Leaves as Determined from Nonsteady-State CO(2) Exchange. PLANT PHYSIOLOGY 1992; 99:298-303. [PMID: 16668865 PMCID: PMC1080439 DOI: 10.1104/pp.99.1.298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The activation kinetics of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) following an increase in photon flux density (PFD) were studied by analyzing CO(2) assimilation time courses in spinach leaves (Spinacia oleracea). When leaves were exposed to 45 minutes of darkness before illumination at 690 micromoles per square meter per second, Rubisco activation followed apparent first-order kinetics with a relaxation time of about 3.8 minutes. But when leaves were illuminated for 45 minutes at 160 micromoles per square meter per second prior to illumination at 690 micromoles per square meter per second the relaxation time for Rubisco activation was only 2.1 minutes. The kinetics of this change in relaxation times were investigated by exposing dark-adapted leaves to 160 micromoles per square meter per second for different periods before increasing the PFD to 690 micromoles per square meter per second. It was found that the apparent relaxation time for Rubisco activation changed from 3.8 to 2.1 minutes slowly, requiring at least 8 minutes for completion. This result indicates that at least two sequential, slow processes are involved in light-mediated activation of Rubisco in spinach leaves and that the relaxation times characterizing these two processes are about 4 and 2 minutes, respectively. The kinetics of the first process in the reverse direction and the dependence of the relaxation time for the second process on the magnitude of the increase in PFD were also determined. Evidence that the first slow process is activation of the enzyme Rubisco activase and that the second slow process is the catalytic activation of Rubisco by activase is discussed.
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Affiliation(s)
- I E Woodrow
- Botany Department, James Cook University of North Queensland, Townsville, Queensland 4811, Australia
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