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Gilbert M, Bährs H, Steinberg CEW, Wilhelm C. The artificial humic substance HS1500 does not inhibit photosynthesis of the green alga Desmodesmus armatus in vivo but interacts with the photosynthetic apparatus of isolated spinach thylakoids in vitro. PHOTOSYNTHESIS RESEARCH 2018; 137:403-420. [PMID: 29777430 DOI: 10.1007/s11120-018-0513-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Humic substances (HSs) can influence the growth and composition of freshwater phytoplankton assemblage. Since HSs contain many phenolic and quinonic moieties and cause growth reductions in eco-physiological field experiments, HSs are considered photosystem II herbicides. To test this specific mode of action in vivo and in vitro, respectively, we used intact cells of the green alga Desmodesmus armatus, as well as thylakoids isolated from spinach (Spinacia oleracea) as a model system for the green algal chloroplast. Photosynthetic electron transport was measured as oxygen evolution and variable chlorophyll fluorescence. The in vivo effect of the artificial humic substance HS1500 on algae consisted of no impact on photosynthesis-irradiance curves of intact green algae compared to untreated controls. In contrast, addition of HS1500 to isolated thylakoids resulted in light-induced oxygen consumption (Mehler reaction) as an in vitro effect. Fluorescence induction kinetics of HS-treated thylakoids revealed a large static quenching effect of HS1500, but no inhibitory effect on electron transport. For the case of intact algal cells, we conclude that the highly hydrophilic and rather large molecules of HS1500 are not taken up in effective quantities and, therefore, cannot interfere with photosynthesis. The in vitro tests show that HS1500 has no inhibitory effect on photosystem II but operates as a weak, oxygen-consuming Hill acceptor at photosystem I. Hence, the results indicate that eco-physiological field experiments should focus more strongly on effects of HSs on extracellular features, such as reducing and red-shifting the underwater light field or influencing nutrient availability by cation exchange within the plankton network.
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Affiliation(s)
- Matthias Gilbert
- Institute of Biology, Department of Plant Physiology, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany.
| | - Hanno Bährs
- Aquacopa GmbH, Koppelbergstr. 4, 17166, Teterow, Germany
| | - Christian E W Steinberg
- Department of Biology, Freshwater and Stress Ecology, Humboldt-University Berlin, Arboretum, Späthstraße 80/81, 12437, Berlin, Germany
| | - Christian Wilhelm
- Institute of Biology, Department of Plant Physiology, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany.
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Li Y, Zheng G, Jia Y, Yu X, Zhang X, Yu B, Wang D, Zheng Y, Tian X, Li W. Acyl chain length of phosphatidylserine is correlated with plant lifespan. PLoS One 2014; 9:e103227. [PMID: 25058060 PMCID: PMC4110022 DOI: 10.1371/journal.pone.0103227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 06/30/2014] [Indexed: 01/13/2023] Open
Abstract
Plant lifespan is affected by factors with genetic and environmental bases. The laws governing these two factors and how they affect plant lifespan are unclear. Here we show that the acyl chain length (ACL) of phosphatidylserine (PS) is correlated with plant lifespan. Among the detected eight head-group classes of membrane lipids with lipidomics based on triple quadrupole tandem mass spectrometry, the ACL of PS showed high diversity, in contrast to the ACLs of the other seven classes, which were highly conserved over all stages of development in all plant species and organs and under all conditions that we studied. Further investigation found that acyl chains of PS lengthened during development, senescence, and under environmental stresses and that increasing length was accelerated by promoted- senescence. The acyl chains of PS were limited to a certain carbon number and ceased to increase in length when plants were close to death. These findings suggest that the ACL of PS can count plant lifespan and could be a molecular scale ruler for measuring plant development and senescence.
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Affiliation(s)
- Yan Li
- Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Guowei Zheng
- Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yanxia Jia
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xiaomei Yu
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xudong Zhang
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Buzhu Yu
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Dandan Wang
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yanling Zheng
- Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xuejun Tian
- Department of Biology, Honghe University, Mengzi, Yunnan, China
| | - Weiqi Li
- Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- * E-mail:
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Chen Y, Cothren JT, Chen D, Ibrahim AMH, Lombardini L. Effect of 1-MCP on Cotton Plants under Abiotic Stress Caused by Ethephon. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ajps.2014.520317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Alós E, Roca M, Iglesias DJ, Mínguez-Mosquera MI, Damasceno CMB, Thannhauser TW, Rose JKC, Talón M, Cercós M. An evaluation of the basis and consequences of a stay-green mutation in the navel negra citrus mutant using transcriptomic and proteomic profiling and metabolite analysis. PLANT PHYSIOLOGY 2008; 147:1300-15. [PMID: 18467459 PMCID: PMC2442528 DOI: 10.1104/pp.108.119917] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 05/05/2008] [Indexed: 05/20/2023]
Abstract
A Citrus sinensis spontaneous mutant, navel negra (nan), produces fruit with an abnormal brown-colored flavedo during ripening. Analysis of pigment composition in the wild-type and nan flavedo suggested that typical ripening-related chlorophyll (Chl) degradation, but not carotenoid biosynthesis, was impaired in the mutant, identifying nan as a type C stay-green mutant. nan exhibited normal expression of Chl biosynthetic and catabolic genes and chlorophyllase activity but no accumulation of dephytylated Chl compounds during ripening, suggesting that the mutation is not related to a lesion in any of the principal enzymatic steps in Chl catabolism. Transcript profiling using a citrus microarray indicated that a citrus ortholog of a number of SGR (for STAY-GREEN) genes was expressed at substantially lower levels in nan, both prior to and during ripening. However, the pattern of catabolite accumulation and SGR sequence analysis suggested that the nan mutation is distinct from those in previously described stay-green mutants and is associated with an upstream regulatory step, rather than directly influencing a specific component of Chl catabolism. Transcriptomic and comparative proteomic profiling further indicated that the nan mutation resulted in the suppressed expression of numerous photosynthesis-related genes and in the induction of genes that are associated with oxidative stress. These data, along with metabolite analyses, suggest that nan fruit employ a number of molecular mechanisms to compensate for the elevated Chl levels and associated photooxidative stress.
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Affiliation(s)
- Enriqueta Alós
- Instituto Valenciano de Investigaciones Agrarias, Centro de Genómica, 46113 Moncada, Valencia, Spain
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Vera P, Conejero V. Effect of Ethephon on Protein Degradation and the Accumulation of ;Pathogenesis-Related' (PR) Proteins in Tomato Leaf Discs. PLANT PHYSIOLOGY 1990; 92:227-33. [PMID: 16667251 PMCID: PMC1062274 DOI: 10.1104/pp.92.1.227] [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 effect of ethephon (2-chloroetylphosphonic acid) on the degradation of proteins and on the induction of Lycopersicon esculentum pathogenesis-related (PR) proteins was studied in tomato leaf discs. The rate of ribulose, -1,5-bisphosphate carboxylase/oxygenase (Rubisco) degradation was maximal in discs after 48 hours of incubation with 1 millimolar ethephon, leading to complete disappearance of Rubisco after 96 hours. This effect was correlated with an increase in PR protein synthesis and the induction of the previously reported alkaline proteolytic enzyme PR-P69 (P Vera, V Conejero [1988] Plant Physiol 87: 58-63). In vivo pulse-chase experiments demonstrated that ethephon not only affected Rubisco content but that of many other (35)S-labeled proteins as well, indicating that ethylene activates a general and nonspecific mechanism of protein degradation. This effect was partially inhibited in vivo by the action of pCMB, a selective inhibitor of cysteine-proteinases such as P69. These data reinforce the hypothesis that P69 and perhaps other PR proteins are involved in the mechanism of accelerated protein degradation activated by ethylene.
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Affiliation(s)
- P Vera
- Departamento de Biotecnologia, Universidad Politécnica de Valencia, 46021-Valencia, Spain
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Blswal U, Biswal B. Ultrastructural Modifications and Biochemical Changes during Senescence of Chloroplasts. INTERNATIONAL REVIEW OF CYTOLOGY 1988. [DOI: 10.1016/s0074-7696(08)60851-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Taylor GE, Gunderson CA. Physiological Site of Ethylene Effects on Carbon Dioxide Assimilation in Glycine max L. Merr. PLANT PHYSIOLOGY 1988; 86:85-92. [PMID: 16665899 PMCID: PMC1054433 DOI: 10.1104/pp.86.1.85] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The physiological site of ethylene action on CO(2) assimilation was investigated in intact plants of Glycine max L., using a whole-plant, open exposure system equipped witha remotely operated single-leaf cuvette. The objective of the study was met by investigating in control and ethylene-treated plants the (a) synchrony in response of CO(2) assimilation, stomatal conductance to water vapor, and substomatal CO(2) partial pressure; (b) response of CO(2) assimilation as a function of a range of substomatal CO(2) partial pressures; and (c) response of CO(2) assimilation as a function of a range of photon flux densities. After exposure to 410 micromoles per cubic meter of ethylene for 2.0 hours, CO(2) assimilation and stomatal conductance declined in synchrony, while substomatal CO(2) partial pressure remained unchanged until exposure times equaled and exceeded 3.0 hours. Because incipient changes in CO(2) assimilation occurred without a change in the CO(2) partial pressure in the leaf interior, it is concluded that both stomatal physiology and the chloroplast's CO(2) assimilatory capacity were initial sites of ethylene action. After 3.5 hours the effect of ethylene on stomatal conductance and CO(2) assimilation exhibited saturation kinetics, and the effect was substantially more pronounced for stomatal conductance than for CO(2) assimilation. Based on the response of CO(2) assimilation to a range of substomatal CO(2) partial pressures, ethylene did not affect either the CO(2) compensation point or carboxylation efficiency at subsaturating CO(2) partial pressures. Above-ambient supplies of CO(2) did not alleviate the diminished rates of CO(2) assimilation. In partitioning the limitations imposed on CO(2) assimilation in control and ethylene-treated plants, the stomatal component accounted for only 16 and 4%, respectively. The response of CO(2) assimilation to a range of photon flux densities suggests that ethylene reduced apparent quantum yield by nearly 50%. Thus, the pronounced decline in net photosynthetic CO(2) assimilation in the presence of ethylene was due more to a loss in the mesophyll tissue's intrinsic capacity to assimilate CO(2) than to a reduction in stomatal conductance.
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Affiliation(s)
- G E Taylor
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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