1
|
Calzadilla PI, Song J, Gallois P, Johnson GN. Proximity to Photosystem II is necessary for activation of Plastid Terminal Oxidase (PTOX) for photoprotection. Nat Commun 2024; 15:287. [PMID: 38177155 PMCID: PMC10767095 DOI: 10.1038/s41467-023-44454-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024] Open
Abstract
The Plastid Terminal Oxidase (PTOX) is a chloroplast localized plastoquinone oxygen oxidoreductase suggested to have the potential to act as a photoprotective safety valve for photosynthesis. However, PTOX overexpression in plants has been unsuccessful at inducing photoprotection, and the factors that control its activity remain elusive. Here, we show that significant PTOX activity is induced in response to high light in the model species Eutrema salsugineum and Arabidopsis thaliana. This activation correlates with structural reorganization of the thylakoid membrane. Over-expression of PTOX in mutants of Arabidopsis thaliana perturbed in thylakoid stacking also results in such activity, in contrast to wild type plants with normal granal structure. Further, PTOX activation protects against photoinhibition of Photosystem II and reduces reactive oxygen production under stress conditions. We conclude that structural re-arrangements of the thylakoid membranes, bringing Photosystem II and PTOX into proximity, are both required and sufficient for PTOX to act as a Photosystem II sink and play a role in photoprotection.
Collapse
Affiliation(s)
- Pablo Ignacio Calzadilla
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Junliang Song
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Patrick Gallois
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Giles Nicholas Johnson
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom.
| |
Collapse
|
2
|
Wei H, He W, Li Z, Ge L, Zhang J, Liu T. Salt-tolerant endophytic bacterium Enterobacter ludwigii B30 enhance bermudagrass growth under salt stress by modulating plant physiology and changing rhizosphere and root bacterial community. FRONTIERS IN PLANT SCIENCE 2022; 13:959427. [PMID: 35982708 PMCID: PMC9380843 DOI: 10.3389/fpls.2022.959427] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Osmotic and ionic induced salt stress suppresses plant growth. In a previous study, Enterobacter ludwigii B30, isolated from Paspalum vaginatum, improved seed germination, root length, and seedling length of bermudagrass (Cynodon dactylon) under salt stress. In this study, E. ludwigii B30 application improved fresh weight and dry weight, carotenoid and chlorophyll levels, catalase and superoxide dismutase activities, indole acetic acid content and K+ concentration. Without E. ludwigii B30 treatment, bermudagrass under salt stress decreased malondialdehyde and proline content, Y(NO) and Y(NPQ), Na+ concentration, 1-aminocyclopropane-1-carboxylate, and abscisic acid content. After E. ludwigii B30 inoculation, bacterial community richness and diversity in the rhizosphere increased compared with the rhizosphere adjacent to roots under salt stress. Turf quality and carotenoid content were positively correlated with the incidence of the phyla Chloroflexi and Fibrobacteres in rhizosphere soil, and indole acetic acid (IAA) level was positively correlated with the phyla Actinobacteria and Chloroflexi in the roots. Our results suggest that E. ludwigii B30 can improve the ability of bermudagrass to accumulate biomass, adjust osmosis, improve photosynthetic efficiency and selectively absorb ions for reducing salt stress-induced injury, while changing the bacterial community structure of the rhizosphere and bermudagrass roots. They also provide a foundation for understanding how the bermudagrass rhizosphere and root microorganisms respond to endophyte inoculation.
Collapse
Affiliation(s)
- Hongjian Wei
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, China
| | - Wenyuan He
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Ziji Li
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, China
| | - Liangfa Ge
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, China
| | - Juming Zhang
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, China
| | - Tianzeng Liu
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Engineering Research Center for Grassland Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
3
|
Wasilewska-Dębowska W, Zienkiewicz M, Drozak A. How Light Reactions of Photosynthesis in C4 Plants Are Optimized and Protected under High Light Conditions. Int J Mol Sci 2022; 23:ijms23073626. [PMID: 35408985 PMCID: PMC8998801 DOI: 10.3390/ijms23073626] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Most C4 plants that naturally occur in tropical or subtropical climates, in high light environments, had to evolve a series of adaptations of photosynthesis that allowed them to grow under these conditions. In this review, we summarize mechanisms that ensure the balancing of energy distribution, counteract photoinhibition, and allow the dissipation of excess light energy. They secure effective electron transport in light reactions of photosynthesis, which will lead to the production of NADPH and ATP. Furthermore, a higher content of the cyclic electron transport components and an increase in ATP production are observed, which is necessary for the metabolism of C4 for effective assimilation of CO2. Most of the data are provided by studies of the genus Flaveria, where species belonging to different metabolic subtypes and intermediate forms between C3 and C4 are present. All described mechanisms that function in mesophyll and bundle sheath chloroplasts, into which photosynthetic reactions are divided, may differ in metabolic subtypes as a result of the different organization of thylakoid membranes, as well as the different demand for ATP and NADPH. This indicates that C4 plants have plasticity in the utilization of pathways in which efficient use and dissipation of excitation energy are realized.
Collapse
|
4
|
Walter J, Kromdijk J. Here comes the sun: How optimization of photosynthetic light reactions can boost crop yields. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:564-591. [PMID: 34962073 PMCID: PMC9302994 DOI: 10.1111/jipb.13206] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/22/2021] [Indexed: 05/22/2023]
Abstract
Photosynthesis started to evolve some 3.5 billion years ago CO2 is the substrate for photosynthesis and in the past 200-250 years, atmospheric levels have approximately doubled due to human industrial activities. However, this time span is not sufficient for adaptation mechanisms of photosynthesis to be evolutionarily manifested. Steep increases in human population, shortage of arable land and food, and climate change call for actions, now. Thanks to substantial research efforts and advances in the last century, basic knowledge of photosynthetic and primary metabolic processes can now be translated into strategies to optimize photosynthesis to its full potential in order to improve crop yields and food supply for the future. Many different approaches have been proposed in recent years, some of which have already proven successful in different crop species. Here, we summarize recent advances on modifications of the complex network of photosynthetic light reactions. These are the starting point of all biomass production and supply the energy equivalents necessary for downstream processes as well as the oxygen we breathe.
Collapse
Affiliation(s)
- Julia Walter
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Johannes Kromdijk
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois Urbana‐ChampaignUrbanaIllinois61801USA
| |
Collapse
|
5
|
Essemine J, Qu M, Lyu MJA, Song Q, Khan N, Chen G, Wang P, Zhu XG. Photosynthetic and transcriptomic responses of two C 4 grass species with different NaCl tolerance. JOURNAL OF PLANT PHYSIOLOGY 2020; 253:153244. [PMID: 32818766 DOI: 10.1016/j.jplph.2020.153244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 05/15/2023]
Abstract
This report reveals the effects of salt on the photosynthetic electron transport and transcriptome of the glycophyte Setaria viridis (S. viridis) and its salt-tolerant close relative halophyte Spartina alterniflora (S. alterniflora). S. viridis was unable to survive exposed to sodium chloride (NaCl) levels higher than 100 mM, in contrast, S. alterniflora could tolerate NaCl up to 550 mM, with negligible effect on gas exchange related parameters and conductance of electrons transport chain (gETC). Under salt, the prompt fluorescence (OJIP-curves) exhibits an increase in the O- and J-steps in S. viridis and much less for S. alterniflora. Flowing NaCl stress, a dramatic decline in the photosystem II (PSII) primary photochemistry was observed for S. viridis, as reflected by the drastic drop in Fv/Fm, Fv/Fo and ΦPSII; however, no substantial change was recorded for these parameters in S. alterniflora. Interestingly, we found an increase in the primary PSII photochemistry (ΦPSII) for S. alterniflora with increasing either NaCl concentration or NaCl treatment duration. The NPQ magnitude was strongly enhanced for S. viridis even at a low NaCl (50 mM); however, it remains unchangeable or slightly increased for S. alterniflora at NaCl levels above 400 mM. After NaCl treatment, we found an increase in both the proportion of oxidized P700 and the amount of active P700 in S. viridis and almost no change for S. alterniflora. Under salt, the net photosynthetic rate (A) and stomatal conductance (gs) measurements demonstrate that A decreases earlier in S. viridis, even after one week exposure to only 50 mM NaCl; in contrast, in S. alterniflora, the effect of NaCl on A and gs was minor even after exposure for two weeks to high NaCl levels. For S. viridis exposed to 50 mM NaCl for 12 d, carbon dioxide (CO2) at a concentration of 2000 μL L-1 could not fully restore A to the control (Ctrl) level. Conversely, in S. alterniflora, high CO2 can fully restore A for all NaCl treatments except at 550 mM. RNA-seq data shows a major impact of NaCl on metabolic pathways in S. viridis and we found a number of transcription factors potentially related to NaCl responses. For S. alterniflora, no major changes in the transcriptomic levels were recorded under NaCl stress. To confirm our data analysis of RNA-seq, we performed quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis for randomly selected four genes for each species (8 genes in total) and we found that our results (up- and/or down-regulated genes) are fully consistent and match well our RNA-seq data. Overall, this study showed drastically different photosynthetic and transcriptomic responses of a salt-tolerant C4 grass species and one salt-sensitive C4 grass species to NaCl stress, which suggests that S. alterniflora could be used as a promising model species to study salt tolerance in C4 or monocot species.
Collapse
Affiliation(s)
- Jemaa Essemine
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Mingnan Qu
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Ming-Ju Amy Lyu
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Qingfeng Song
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Naveed Khan
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Genyun Chen
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Peng Wang
- CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China
| | - Xin-Guang Zhu
- National Key Laboratory of Plant Molecular Genetics, CAS-Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, China.
| |
Collapse
|