1
|
Osyczka P, Myśliwa-Kurdziel B. Do the expected heatwaves pose a threat to lichens?: Linkage between a passive decline in water content in thalli and response to heat stress. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38874284 DOI: 10.1111/pce.14999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 05/25/2024] [Accepted: 05/30/2024] [Indexed: 06/15/2024]
Abstract
Being poikilohydric, lichens are inherently exposed to alternating desiccation and hydration cycles. They can exhibit extraordinary resistance to extreme temperatures in a dehydrated state but thermal thresholds for hydrated lichens are lower. The ability of the lichen Cetraria aculeata to recovery after high temperature treatment (40°C, 60°C) at different air humidity levels (relative humidity [RH]: <15%, 25%, 50%, 75%, ≅100%) was examined to find a linkage between passive dehydration of the lichen and its physiological resistance to heat stress. The response to heating was determined by measuring parameters related to photosynthesis and respiration after 2- and 24-h recovery. A higher RH level resulted in a slower decline in relative water content (RWC) in hydrated thalli. In turn, the stress resistance of active thalli depended on the ambient humidity and associated RWC reduction. Elevated temperature had a negative impact on bioenergetic processes, but only an unnatural state of permanent full hydration during heat stress resulted in a lethal effect. Hydrated lichen thalli heated at 40°C and 50% relative humidity (RH) tended to be least susceptible to stress-induced damage. Although atypical climatic conditions may lead lichens to lethal thresholds, the actual likelihood of deadly threat to lichens due to heat events per se is debatable.
Collapse
Affiliation(s)
- Piotr Osyczka
- Institute of Botany, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Beata Myśliwa-Kurdziel
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| |
Collapse
|
2
|
Osyczka P, Kościelniak R, Stanek M. Old-growth forest versus generalist lichens: Sensitivity to prolonged desiccation stress and photosynthesis reactivation rate upon rehydration. Mycologia 2024; 116:31-43. [PMID: 38039398 DOI: 10.1080/00275514.2023.2275460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 10/23/2023] [Indexed: 12/03/2023]
Abstract
Most epiphytic lichens demonstrate high specificity to a habitat type, and sensitive hygrophilous species usually find shelter only in close-to-natural forest complexes. Some of them are considered as old-growth forest and/or long ecological continuity indicators. To evaluate general links between the narrow ecological range and physiological traits, two distinct sets of model lichens, i.e., old-growth forest (Cetrelia cetrarioides (Duby) W.L. Culb. & C.F. Culb., Lobaria pulmonaria (L.) Hoffm., Menegazzia terebrata (Hoffm.) A. Massal.), and generalist (Flavoparmelia caperata (L.) Hale, Hypogymnia physodes (L.) Nyl., Parmelia sulcata Taylor) ones, were examined in terms of sensitivity to long-term desiccation stress (1-, 2-, and 3-month) and photosynthesis activation rate upon rehydration. Desiccation tolerance and response rate to rehydration are specific to a given ecological set of lichens rather than to a particular species. Noticeable delayed and prompt recovery of high photosynthetic activity of photosystem II (PSII) characterize these sets, respectively. At the same time, although a decrease in the potential quantum yield of PSII in lichen thalli with a relative water content (RWC) at the level of 25% was observed, the efficiency remained at a very high level for all species, regardless of habitat preferences. Among the examined lichens, the fluorescence emission parameters for F. caperata were the fastest toward equilibrium upon rehydration, both after a shorter and a longer period of desiccation stress. In contrast to generalist lichens, retrieving of photosynthesis after 3-month desiccation failed in old-growth forest lichens. In the long term, prolonged rainless periods and unfavorable water balance in the environment predicted in the future may have a severely limiting effect on hygrophilous lichens during growing season (also in the sense of species associations) and, at the same time, promote the development of generalists.
Collapse
Affiliation(s)
- Piotr Osyczka
- Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 3, Kraków 30-387, Poland
| | - Robert Kościelniak
- Institute of Botany, Pedagogical University of Krakow, Podchorążych 2, Kraków 30-084, Poland
| | - Małgorzata Stanek
- Laboratory of Ecochemistry and Environmental Engineering, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, Kraków 31-512, Poland
| |
Collapse
|
3
|
Xu HF, Raanan H, Dai GZ, Oren N, Berkowicz S, Murik O, Kaplan A, Qiu BS. Reading and surviving the harsh conditions in desert biological soil crust: The cyanobacterial viewpoint. FEMS Microbiol Rev 2021; 45:6308820. [PMID: 34165541 DOI: 10.1093/femsre/fuab036] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/22/2021] [Indexed: 12/18/2022] Open
Abstract
Biological soil crusts (BSCs) are found in drylands, cover ∼12% of the Earth's surface in arid and semi-arid lands and their destruction is considered an important promoter of desertification. These crusts are formed by the adhesion of soil particles to polysaccharides excreted mostly by filamentous cyanobacteria, which are the pioneers and main primary producers in BSCs. Desert BSCs survive in one of the harshest environments on Earth, and are exposed to daily fluctuations of extreme conditions. The cyanobacteria inhabiting these habitats must precisely read the changing conditions and predict, for example, the forthcoming desiccation. Moreover, they evolved a comprehensive regulation of multiple adaptation strategies to enhance their stress tolerance. Here we focus on what distinguishes cyanobacteria able to revive after dehydration from those that cannot. While important progress has been made in our understanding of physiological, biochemical and omics aspects, clarification of the sensing, signal transduction and responses enabling desiccation tolerance are just emerging. We plot the trajectory of current research and open questions ranging from general strategies and regulatory adaptations in the hydration/desiccation cycle, to recent advances in our understanding of photosynthetic adaptation. The acquired knowledge provides new insights to mitigate desertification and improve plant productivity under drought conditions.
Collapse
Affiliation(s)
- Hai-Feng Xu
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, 430079 China
| | - Hagai Raanan
- Department of Plant Pathology and Weed Research, Gilat Research Center, Agricultural Research Organization, Mobile Post Negev 2, 8531100 Israel
| | - Guo-Zheng Dai
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, 430079 China
| | - Nadav Oren
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401 Israel
| | - Simon Berkowicz
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401 Israel.,Interuniversity Institute for Marine Sciences in Eilat, P.O.B 469, Eilat, 8810302 Israel
| | - Omer Murik
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401 Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401 Israel
| | - Bao-Sheng Qiu
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, 430079 China
| |
Collapse
|
4
|
Gasulla F, del Campo EM, Casano LM, Guéra A. Advances in Understanding of Desiccation Tolerance of Lichens and Lichen-Forming Algae. PLANTS (BASEL, SWITZERLAND) 2021; 10:807. [PMID: 33923980 PMCID: PMC8073698 DOI: 10.3390/plants10040807] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/11/2022]
Abstract
Lichens are symbiotic associations (holobionts) established between fungi (mycobionts) and certain groups of cyanobacteria or unicellular green algae (photobionts). This symbiotic association has been essential in the colonization of terrestrial dry habitats. Lichens possess key mechanisms involved in desiccation tolerance (DT) that are constitutively present such as high amounts of polyols, LEA proteins, HSPs, a powerful antioxidant system, thylakoidal oligogalactolipids, etc. This strategy allows them to be always ready to survive drastic changes in their water content. However, several studies indicate that at least some protective mechanisms require a minimal time to be induced, such as the induction of the antioxidant system, the activation of non-photochemical quenching including the de-epoxidation of violaxanthin to zeaxanthin, lipid membrane remodeling, changes in the proportions of polyols, ultrastructural changes, marked polysaccharide remodeling of the cell wall, etc. Although DT in lichens is achieved mainly through constitutive mechanisms, the induction of protection mechanisms might allow them to face desiccation stress in a better condition. The proportion and relevance of constitutive and inducible DT mechanisms seem to be related to the ecology at which lichens are adapted to.
Collapse
Affiliation(s)
- Francisco Gasulla
- Department of Life Sciences, Universidad de Alcalá, Alcalá de Henares, 28802 Madrid, Spain; (E.M.d.C.); (L.M.C.)
| | | | | | - Alfredo Guéra
- Department of Life Sciences, Universidad de Alcalá, Alcalá de Henares, 28802 Madrid, Spain; (E.M.d.C.); (L.M.C.)
| |
Collapse
|
5
|
Barták M, Hájek J, Orekhova A, Villagra J, Marín C, Palfner G, Casanova-Katny A. Inhibition of Primary Photosynthesis in Desiccating Antarctic Lichens Differing in Their Photobionts, Thallus Morphology, and Spectral Properties. Microorganisms 2021; 9:microorganisms9040818. [PMID: 33924436 PMCID: PMC8070113 DOI: 10.3390/microorganisms9040818] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Five macrolichens of different thallus morphology from Antarctica (King George Island) were used for this ecophysiological study. The effect of thallus desiccation on primary photosynthetic processes was examined. We investigated the lichens' responses to the relative water content (RWC) in their thalli during the transition from a wet (RWC of 100%) to a dry state (RWC of 0%). The slow Kautsky kinetics of chlorophyll fluorescence (ChlF) that was recorded during controlled dehydration (RWC decreased from 100 to 0%) and supplemented with a quenching analysis revealed a polyphasic species-specific response of variable fluorescence. The changes in ChlF at a steady state (Fs), potential and effective quantum yields of photosystem II (FV/FM, ΦPSII), and nonphotochemical quenching (NPQ) reflected a desiccation-induced inhibition of the photosynthetic processes. The dehydration-dependent fall in FV/FM and ΦPSII was species-specific, starting at an RWC range of 22-32%. The critical RWC for ΦPSII was below 5%. The changes indicated the involvement of protective mechanisms in the chloroplastic apparatus of lichen photobionts at RWCs of below 20%. In both the wet and dry states, the spectral reflectance curves (SRC) (wavelength 400-800 nm) and indices (NDVI, PRI) of the studied lichen species were measured. Black Himantormia lugubris showed no difference in the SRCs between wet and dry state. Other lichens showed a higher reflectance in the dry state compared to the wet state. The lichen morphology and anatomy data, together with the ChlF and spectral reflectance data, are discussed in relation to its potential for ecophysiological studies in Antarctic lichens.
Collapse
Affiliation(s)
- Miloš Barták
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Josef Hájek
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Alla Orekhova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Johana Villagra
- Laboratory of Plant Ecophysiology, Faculty of Natural Resources, Campus Luis Rivas del Canto, Catholic University of Temuco, Rudecindo Ortega #03694, 4780000 Temuco, Chile;
| | - Catalina Marín
- Laboratory of Mycology and Mycorrhiza, Faculty of Natural Sciences and Oceanography, Campus Concepción, Concepción University, 4030000 Concepción, Chile; (C.M.); (G.P.)
| | - Götz Palfner
- Laboratory of Mycology and Mycorrhiza, Faculty of Natural Sciences and Oceanography, Campus Concepción, Concepción University, 4030000 Concepción, Chile; (C.M.); (G.P.)
| | - Angélica Casanova-Katny
- Laboratory of Plant Ecophysiology, Faculty of Natural Resources, Campus Luis Rivas del Canto, Catholic University of Temuco, Rudecindo Ortega #03694, 4780000 Temuco, Chile;
- Correspondence: ; Tel.: +56-96-209-7709
| |
Collapse
|
6
|
Du W, Ruan C, Li J, Li H, Ding J, Zhao S, Jiang X. Quantitative proteomic analysis of Xanthoceras sorbifolium Bunge seedlings in response to drought and heat stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 160:8-17. [PMID: 33445043 DOI: 10.1016/j.plaphy.2021.01.002] [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: 10/13/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
Yellowhorn (Xanthoceras sorbifolium Bunge) is a woody oil species that is widely distributed in northwestern China. To investigate the molecular mechanisms underlying the drought and heat tolerance response of yellowhorn seedlings, changes in protein abundance were analyzed via comparative proteomics. Drought and heat treatment of seedlings was applied in growth chamber, and the leaves were harvested after 7 days of treatment. The total protein was extracted, and comparative proteomic analysis was performed via isobaric tag for relative and absolute quantitation (iTRAQ). The abundance of most of the proteins associated with oxidative phosphorylation, NADH dehydrogenase and superoxide dismutase (SOD) was reduced. The differential proteins associated with photosynthesis enzymes indicated that stress had different effects on photosystem I (PSI) and photosystem II (PSII). After comprehensively analyzing the results, we speculated that drought and heat stress could hinder the synthesis of riboflavin, reducing NADH dehydrogenase content, which might further have an impact on energy utilization. Yellowhorn seedlings relied on Fe-Mn SOD enzymes rather than Cu/Zn SOD enzymes to remove reactive oxygen species (ROS). In addition, heat-shock proteins (HSPs) had significant increase and played a key role in stress response, which could be divided into two categories according to their transcription and translation efficiency. Over all, the results can provide a basis for understanding the molecular mechanism underlying resistance to drought and heat stress in yellowhorn and for subsequent research of posttranslational modification-related omics of key proteins.
Collapse
Affiliation(s)
- Wei Du
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| | - Chengjiang Ruan
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China.
| | - Jingbin Li
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| | - He Li
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| | - Jian Ding
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| | - Siyang Zhao
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| | - Xin Jiang
- Institute of Plant Resources, Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Nationalities University, Dalian, 116600, China
| |
Collapse
|
7
|
Bhatti AF, Choubeh RR, Kirilovsky D, Wientjes E, van Amerongen H. State transitions in cyanobacteria studied with picosecond fluorescence at room temperature. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148255. [PMID: 32619427 DOI: 10.1016/j.bbabio.2020.148255] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 11/30/2022]
Abstract
Cyanobacteria can rapidly regulate the relative activity of their photosynthetic complexes photosystem I and II (PSI and PSII) in response to changes in the illumination conditions. This process is known as state transitions. If PSI is preferentially excited, they go to state I whereas state II is induced either after preferential excitation of PSII or after dark adaptation. Different underlying mechanisms have been proposed in literature, in particular i) reversible shuttling of the external antenna complexes, the phycobilisomes, between PSI and PSII, ii) reversible spillover of excitation energy from PSII to PSI, iii) a combination of both and, iv) increased excited-state quenching of the PSII core in state II. Here we investigated wild-type and mutant strains of Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 using time-resolved fluorescence spectroscopy at room temperature. Our observations support model iv, meaning that increased excited-state quenching of the PSII core occurs in state II thereby balancing the photochemistry of photosystems I and II.
Collapse
Affiliation(s)
- Ahmad Farhan Bhatti
- Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands
| | | | - Diana Kirilovsky
- Institute for Integrative Biology of the Cell (12BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, Wageningen, the Netherlands.
| |
Collapse
|
8
|
Cho SM, Lee H, Hong SG, Lee J. Study of Ecophysiological Responses of the Antarctic Fruticose Lichen Cladonia borealis Using the PAM Fluorescence System under Natural and Laboratory Conditions. PLANTS (BASEL, SWITZERLAND) 2020; 9:E85. [PMID: 31936612 PMCID: PMC7020452 DOI: 10.3390/plants9010085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/20/2019] [Accepted: 01/07/2020] [Indexed: 11/16/2022]
Abstract
Antarctic lichens have been used as indicators of climate change for decades, but only a few species have been studied. We assessed the photosynthetic performance of the fruticose lichen Cladonia borealis under natural and laboratory conditions using the PAM fluorescence system. Compared to that of sun-adapted Usnea sp., the photosynthetic performance of C. borealis exhibits shade-adapted lichen features, and its chlorophyll fluorescence does not occur during dry days without rain. To understand its desiccation-rehydration responses, we measured changes in the PSII photochemistry in C. borealis under the average light intensity of dawn light and daylight and the desiccating conditions of its natural microclimate. Interestingly, samples under daylight and rapid-desiccation conditions showed a delayed reduction in Fv'/Fm' and rETRmax, and an increase in Y(II) and Y(NPQ) levels. These results suggest that the photoprotective mechanism of C. borealis depends on sunlight and becomes more efficient with improved desiccation tolerance. Amplicon sequencing revealed that the major photobiont of C. borealis was Asterochloris irregularis, which has not been reported in Antarctica before. Collectively, these results from both field and laboratory could provide a better understanding of specific ecophysiological responses of shade-adapted lichens in the Antarctic region.
Collapse
Affiliation(s)
- Sung Mi Cho
- Unit of Research for Practical Application, Korea Polar Research Institute, Incheon 21990, Korea;
| | - Hyoungseok Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, Korea; (H.L.); (S.G.H.)
- Polar Sciences, University of Science and Technology, Daejeon 34114, Korea
| | - Soon Gyu Hong
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, Korea; (H.L.); (S.G.H.)
| | - Jungeun Lee
- Unit of Research for Practical Application, Korea Polar Research Institute, Incheon 21990, Korea;
| |
Collapse
|
9
|
Ranjbar Choubeh R, Bar-Eyal L, Paltiel Y, Keren N, Struik PC, van Amerongen H. Photosystem II core quenching in desiccated Leptolyngbya ohadii. PHOTOSYNTHESIS RESEARCH 2020; 143:13-18. [PMID: 31535258 PMCID: PMC6930311 DOI: 10.1007/s11120-019-00675-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 09/10/2019] [Indexed: 05/28/2023]
Abstract
Cyanobacteria living in the harsh environment of the desert have to protect themselves against high light intensity and prevent photodamage. These cyanobacteria are in a desiccated state during the largest part of the day when both temperature and light intensity are high. In the desiccated state, their photosynthetic activity is stopped, whereas upon rehydration the ability to perform photosynthesis is regained. Earlier reports indicate that light-induced excitations in Leptolyngbya ohadii are heavily quenched in the desiccated state, because of a loss of structural order of the light-harvesting phycobilisome structures (Bar Eyal et al. in Proc Natl Acad Sci 114:9481, 2017) and via the stably oxidized primary electron donor in photosystem I, namely P700+ (Bar Eyal et al. in Biochim Biophys Acta Bioenergy 1847:1267-1273, 2015). In this study, we use picosecond fluorescence experiments to demonstrate that a third protection mechanism exists, in which the core of photosystem II is quenched independently.
Collapse
Affiliation(s)
| | - Leeat Bar-Eyal
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yossi Paltiel
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nir Keren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Paul C Struik
- Centre for Crop Systems Analysis, Wageningen University, Wageningen, The Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands.
- MicroSpectroscopy Research Facility, Wageningen University, Wageningen, The Netherlands.
| |
Collapse
|
10
|
Vinyard DJ, Ananyev GM, Dismukes GC. Desiccation tolerant lichens facilitate in vivo H/D isotope effect measurements in oxygenic photosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1039-1044. [DOI: 10.1016/j.bbabio.2018.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/21/2018] [Accepted: 05/23/2018] [Indexed: 10/14/2022]
|
11
|
Wieners PC, Mudimu O, Bilger W. Survey of the occurrence of desiccation-induced quenching of basal fluorescence in 28 species of green microalgae. PLANTA 2018; 248:601-612. [PMID: 29846774 DOI: 10.1007/s00425-018-2925-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Desiccation-induced chlorophyll fluorescence quenching seems to be an indispensable part of desiccation resistance in the surveyed 28 green microalgal species. Lichens are desiccation tolerant meta-organisms. In the desiccated state photosynthesis is inhibited rendering the photobionts potentially sensitive to photoinhibition. As a photoprotective mechanism, strong non-radiative dissipation of absorbed light leading to quenching of chlorophyll fluorescence has been proposed. Desiccation-induced quenching affects not only variable fluorescence, but also the so-called basal fluorescence, F0. This phenomenon is well-known for intact lichens and some free living aero-terrestrial algae, but it was often absent in isolated lichen algae. Therefore, a thorough screening for the appearance of desiccation-induced quenching was undertaken with 13 different aero-terrestrial microalgal species and lichen photobionts. They were compared with 15 aquatic green microalgal species, among them also three marine species. We asked the following questions: Do isolated lichen algae show desiccation-induced quenching? Are aero-terrestrial algae different in this respect to aquatic algae and is the potential for desiccation-induced quenching coupled to desiccation tolerance? How variable is desiccation-induced quenching among species? Most of the aero-terrestrial algae, including all lichen photobionts, showed desiccation-induced quenching, although highly variable in extent, whereas most of the aquatic algae did not. All algae displaying quenching were also desiccation tolerant, whereas all algae unable to perform desiccation-induced quenching were desiccation intolerant. Desiccation-induced fluorescence quenching seems to be an indispensable part of desiccation resistance in the investigated species.
Collapse
Affiliation(s)
- Paul Christian Wieners
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany.
| | - Opayi Mudimu
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany
| | - Wolfgang Bilger
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany
| |
Collapse
|
12
|
Yamakawa H, van Stokkum IHM, Heber U, Itoh S. Mechanisms of drought-induced dissipation of excitation energy in sun- and shade-adapted drought-tolerant mosses studied by fluorescence yield change and global and target analysis of fluorescence decay kinetics. PHOTOSYNTHESIS RESEARCH 2018; 135:285-298. [PMID: 29151177 DOI: 10.1007/s11120-017-0465-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 11/08/2017] [Indexed: 06/07/2023]
Abstract
Some mosses stay green and survive long even under desiccation. Dissipation mechanisms of excess excitation energy were studied in two drought-tolerant moss species adapted to contrasting niches: shade-adapted Rhytidiadelphus squarrosus and sun-adapted Rhytidium rugosum in the same family. (1) Under wet conditions, a light-induced nonphotochemical quenching (NPQ) mechanism decreased the yield of photosystem II (PSII) fluorescence in both species. The NPQ extent saturated at a lower illumination intensity in R. squarrosus, suggesting a larger PSII antenna size. (2) Desiccation reduced the fluorescence intensities giving significantly lower F 0 levels and shortened the overall fluorescence lifetimes in both R. squarrosus and R. rugosum, at room temperature. (3) At 77 K, desiccation strongly reduced the PSII fluorescence intensity. This reduction was smaller in R. squarrosus than in R. rugosum. (4) Global and target analysis indicated two different mechanisms of energy dissipation in PSII under desiccation: the energy dissipation to a desiccation-formed strong fluorescence quencher in the PSII core in sun-adapted R. rugosum (type-A quenching) and (5) the moderate energy dissipation in the light-harvesting complex/PSII in shade-adapted R. squarrosus (type-B quenching). The two mechanisms are consistent with the different ecological niches of the two mosses.
Collapse
Affiliation(s)
- Hisanori Yamakawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Furocyo, Chikusa, Nagoya, 464-8602, Japan
| | - Ivo H M van Stokkum
- Faculty of Science, Institute for Lasers, Life and Biophotonics, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Ulrich Heber
- Julius von Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - Shigeru Itoh
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocyo, Chikusa, Nagoya, 464-8602, Japan.
| |
Collapse
|
13
|
Pierangelini M, Ryšánek D, Lang I, Adlassnig W, Holzinger A. Terrestrial adaptation of green algae Klebsormidium and Zygnema (Charophyta) involves diversity in photosynthetic traits but not in CO 2 acquisition. PLANTA 2017; 246:971-986. [PMID: 28721563 PMCID: PMC5633629 DOI: 10.1007/s00425-017-2741-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/09/2017] [Indexed: 05/20/2023]
Abstract
The basal streptophyte Klebsormidium and the advanced Zygnema show adaptation to terrestrialization. Differences are found in photoprotection and resistance to short-term light changes, but not in CO 2 acquisition. Streptophyte green algae colonized land about 450-500 million years ago giving origin to terrestrial plants. We aim to understand how their physiological adaptations are linked to the ecological conditions (light, water and CO2) characterizing modern terrestrial habitats. A new Klebsormidium isolate from a strongly acidic environment of a former copper mine (Schwarzwand, Austria) is investigated, in comparison to Klebsormidium cf. flaccidum and Zygnema sp. We show that these genera possess different photosynthetic traits and water requirements. Particularly, the Klebsormidium species displayed a higher photoprotection capacity, concluded from non-photochemical quenching (NPQ) and higher tolerance to high light intensity than Zygnema. However, Klebsormidium suffered from photoinhibition when the light intensity in the environment increased rapidly, indicating that NPQ is involved in photoprotection against strong and stable irradiance. Klebsormidium was also highly resistant to cellular water loss (dehydration) under low light. On the other hand, exposure to relatively high light intensity during dehydration caused a harmful over-reduction of the electron transport chain, leading to PSII damages and impairing the ability to recover after rehydration. Thus, we suggest that dehydration is a selective force shaping the adaptation of this species towards low light. Contrary to the photosynthetic characteristics, the inorganic carbon (C i ) acquisition was equivalent between Klebsormidium and Zygnema. Despite their different habitats and restriction to hydro-terrestrial environment, the three organisms showed similar use of CO2 and HCO3- as source of Ci for photosynthesis, pointing out a similar adaptation of their CO2-concentrating mechanisms to terrestrial life.
Collapse
Affiliation(s)
- Mattia Pierangelini
- Department of Botany, Functional Plant Biology, University of Innsbruck, 6020, Innsbruck, Austria
| | - David Ryšánek
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, 12801, Prague 2, Czech Republic
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, v. v. i., Průmyslová 595, 252 42, Vestec, Czech Republic
| | - Ingeborg Lang
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Wolfram Adlassnig
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Andreas Holzinger
- Department of Botany, Functional Plant Biology, University of Innsbruck, 6020, Innsbruck, Austria.
| |
Collapse
|
14
|
Miralles I, Jorge-Villar SE, van Wesemael B, Lázaro R. Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 171:40-51. [PMID: 27472170 DOI: 10.1016/j.saa.2016.07.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). "Species" was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed.
Collapse
Affiliation(s)
- I Miralles
- Earth and Life Institute, Université Catholique de Louvain, Louvain, -La-Neuve, Belgium; Experimental Station of Arid Zones (CSIC), Almería, Spain.
| | - S E Jorge-Villar
- Area de Geodinamica Interna, University of Burgos, Spain; National Center of Research in Human Evolution (CENIEH), Spain
| | - B van Wesemael
- Earth and Life Institute, Université Catholique de Louvain, Louvain, -La-Neuve, Belgium
| | - R Lázaro
- Experimental Station of Arid Zones (CSIC), Almería, Spain
| |
Collapse
|
15
|
Fesenko I, Seredina A, Arapidi G, Ptushenko V, Urban A, Butenko I, Kovalchuk S, Babalyan K, Knyazev A, Khazigaleeva R, Pushkova E, Anikanov N, Ivanov V, Govorun VM. The Physcomitrella patens Chloroplast Proteome Changes in Response to Protoplastation. FRONTIERS IN PLANT SCIENCE 2016; 7:1661. [PMID: 27867392 PMCID: PMC5095126 DOI: 10.3389/fpls.2016.01661] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/21/2016] [Indexed: 05/29/2023]
Abstract
Plant protoplasts are widely used for genetic manipulation and functional studies in transient expression systems. However, little is known about the molecular pathways involved in a cell response to the combined stress factors resulted from protoplast generation. Plants often face more than one type of stress at a time, and how plants respond to combined stress factors is therefore of great interest. Here, we used protoplasts of the moss Physcomitrella patens as a model to study the effects of short-term stress on the chloroplast proteome. Using label-free comparative quantitative proteomic analysis (SWATH-MS), we quantified 479 chloroplast proteins, 219 of which showed a more than 1.4-fold change in abundance in protoplasts. We additionally quantified 1451 chloroplast proteins using emPAI. We observed degradation of a significant portion of the chloroplast proteome following the first hour of stress imposed by the protoplast isolation process. Electron-transport chain (ETC) components underwent the heaviest degradation, resulting in the decline of photosynthetic activity. We also compared the proteome changes to those in the transcriptional level of nuclear-encoded chloroplast genes. Globally, the levels of the quantified proteins and their corresponding mRNAs showed limited correlation. Genes involved in the biosynthesis of chlorophyll and components of the outer chloroplast membrane showed decreases in both transcript and protein abundance. However, proteins like dehydroascorbate reductase 1 and 2-cys peroxiredoxin B responsible for ROS detoxification increased in abundance. Further, genes such as thylakoid ascorbate peroxidase were induced at the transcriptional level but down-regulated at the proteomic level. Together, our results demonstrate that the initial chloroplast reaction to stress is due changes at the proteomic level.
Collapse
Affiliation(s)
- Igor Fesenko
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Anna Seredina
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Georgij Arapidi
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Vasily Ptushenko
- Department of Bioenergetics, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State UniversityMoscow, Russia
- Department of Biocatalysis, Emanuel Institute of Biochemical Physics, Russian Academy of SciencesMoscow, Russia
| | - Anatoly Urban
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Ivan Butenko
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical MedicineMoscow, Russia
| | - Sergey Kovalchuk
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Konstantin Babalyan
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Andrey Knyazev
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Regina Khazigaleeva
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Elena Pushkova
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Nikolai Anikanov
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Vadim Ivanov
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
| | - Vadim M. Govorun
- Laboratory of Proteomics, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of SciencesMoscow, Russia
- Laboratory of the Proteomic Analysis, Research Institute for Physico-Chemical MedicineMoscow, Russia
| |
Collapse
|
16
|
Raanan H, Oren N, Treves H, Keren N, Ohad I, Berkowicz SM, Hagemann M, Koch M, Shotland Y, Kaplan A. Towards clarifying what distinguishes cyanobacteria able to resurrect after desiccation from those that cannot: The photosynthetic aspect. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:715-22. [DOI: 10.1016/j.bbabio.2016.02.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/26/2016] [Accepted: 02/13/2016] [Indexed: 11/24/2022]
|
17
|
Treves H, Raanan H, Kedem I, Murik O, Keren N, Zer H, Berkowicz SM, Giordano M, Norici A, Shotland Y, Ohad I, Kaplan A. The mechanisms whereby the green alga Chlorella ohadii, isolated from desert soil crust, exhibits unparalleled photodamage resistance. THE NEW PHYTOLOGIST 2016; 210:1229-43. [PMID: 26853530 DOI: 10.1111/nph.13870] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/16/2015] [Indexed: 05/24/2023]
Abstract
Excess illumination damages the photosynthetic apparatus with severe implications with regard to plant productivity. Unlike model organisms, the growth of Chlorella ohadii, isolated from desert soil crust, remains unchanged and photosynthetic O2 evolution increases, even when exposed to irradiation twice that of maximal sunlight. Spectroscopic, biochemical and molecular approaches were applied to uncover the mechanisms involved. D1 protein in photosystem II (PSII) is barely degraded, even when exposed to antibiotics that prevent its replenishment. Measurements of various PSII parameters indicate that this complex functions differently from that in model organisms and suggest that C. ohadii activates a nonradiative electron recombination route which minimizes singlet oxygen formation and the resulting photoinhibition. The light-harvesting antenna is very small and carotene composition is hardly affected by excess illumination. Instead of succumbing to photodamage, C. ohadii activates additional means to dissipate excess light energy. It undergoes major structural, compositional and physiological changes, leading to a large rise in photosynthetic rate, lipids and carbohydrate content and inorganic carbon cycling. The ability of C. ohadii to avoid photodamage relies on a modified function of PSII and the dissipation of excess reductants downstream of the photosynthetic reaction centers. The biotechnological potential as a gene source for crop plant improvement is self-evident.
Collapse
Affiliation(s)
- Haim Treves
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Hagai Raanan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Isaac Kedem
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Omer Murik
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Hagit Zer
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Simon M Berkowicz
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, 60131, Italy
| | - Alessandra Norici
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, 60131, Italy
| | - Yoram Shotland
- Department of Chemical Engineering, Shamoon College of Engineering, Beer Sheva, 84100, Israel
| | - Itzhak Ohad
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| |
Collapse
|
18
|
Guéra A, Gasulla F, Barreno E. Formation of photosystem II reaction centers that work as energy sinks in lichen symbiotic Trebouxiophyceae microalgae. PHOTOSYNTHESIS RESEARCH 2016; 128:15-33. [PMID: 26482588 DOI: 10.1007/s11120-015-0196-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
Lichens are poikilohydric symbiotic organisms that can survive in the absence of water. Photosynthesis must be highly regulated in these organisms, which live under continuous desiccation-rehydration cycles, to avoid photooxidative damage. Analysis of chlorophyll a fluorescence induction curves in the lichen microalgae of the Trebouxiophyceae Asterochloris erici and in Trebouxia jamesii (TR1) and Trebouxia sp. (TR9) phycobionts, isolated from the lichen Ramalina farinacea, shows differences with higher plants. In the presence of the photosynthetic electron transport inhibitor DCMU, the kinetics of Q(A) reduction is related to variable fluorescence by a sigmoidal function that approaches a horizontal asymptote. An excellent fit to these curves was obtained by applying a model based on the following assumptions: (1) after closure, the reaction centers (RCs) can be converted into "energy sink" centers (sRCs); (2) the probability of energy leaving the sRCs is very low or zero and (3) energy is not transferred from the antenna of PSII units with sRCs to other PSII units. The formation of sRCs units is also induced by repetitive light saturating pulses or at the transition from dark to light and probably requires the accumulation of reduced Q(A), as well as structural changes in the reaction centers of PSII. This type of energy sink would provide a very efficient way to protect symbiotic microalgae against abrupt changes in light intensity.
Collapse
Affiliation(s)
- Alfredo Guéra
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus externo, 28871, Alcalá de Henares, Madrid, Spain.
| | - Francisco Gasulla
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus externo, 28871, Alcalá de Henares, Madrid, Spain
- Botánica, ICBIBE, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, Valencia, Spain
| | - Eva Barreno
- Botánica, ICBIBE, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, Valencia, Spain
| |
Collapse
|
19
|
Flores-Bavestrello A, Król M, Ivanov AG, Hüner NPA, García-Plazaola JI, Corcuera LJ, Bravo LA. Two Hymenophyllaceae species from contrasting natural environments exhibit a homoiochlorophyllous strategy in response to desiccation stress. JOURNAL OF PLANT PHYSIOLOGY 2016; 191:82-94. [PMID: 26720213 DOI: 10.1016/j.jplph.2015.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/07/2015] [Accepted: 12/10/2015] [Indexed: 05/28/2023]
Abstract
Hymenophyllaceae is a desiccation tolerant family of Pteridophytes which are poikilohydric epiphytes. Their fronds are composed by a single layer of cells and lack true mesophyll cells and stomata. Although they are associated with humid and shady environments, their vertical distribution varies along the trunk of the host plant with some species inhabiting the drier sides with a higher irradiance. The aim of this work was to compare the structure and function of the photosynthetic apparatus during desiccation and rehydration in two species, Hymenophyllum dentatum and Hymenoglossum cruentum, isolated from a contrasting vertical distribution along the trunk of their hosts. Both species were subjected to desiccation and rehydration kinetics to analyze frond phenotypic plasticity, as well as the structure, composition and function of the photosynthetic apparatus. Minimal differences in photosynthetic pigments were observed upon dehydration. Measurements of ϕPSII (effective quantum yield of PSII), ϕNPQ (quantum yield of the regulated energy dissipation of PSII), ϕNO (quantum yield of non-regulated energy dissipation of PSII), and TL (thermoluminescence) indicate that both species convert a functional photochemical apparatus into a structure which exhibits maximum quenching capacity in the dehydrated state with minimal changes in photosynthetic pigments and polypeptide compositions. This dehydration-induced conversion in the photosynthetic apparatus is completely reversible upon rehydration. We conclude that H. dentatum and H. cruentum are homoiochlorophyllous with respect to desiccation stress and exhibited no correlation between inherent desiccation tolerance and the vertical distribution along the host tree trunk.
Collapse
Affiliation(s)
| | - Marianna Król
- Department of Biology and The Biotron Centre for Experimental Climate Change Research, Western University, London, Ontario, N6A 5B7, Canada.
| | - Alexander G Ivanov
- Department of Biology and The Biotron Centre for Experimental Climate Change Research, Western University, London, Ontario, N6A 5B7, Canada.
| | - Norman P A Hüner
- Department of Biology and The Biotron Centre for Experimental Climate Change Research, Western University, London, Ontario, N6A 5B7, Canada.
| | - José Ignacio García-Plazaola
- Departamento de Biología Vegetal y Ecología, Universidad del País Vasco (UPV/EHU), Aptdo. 644, E-48080 Bilbao, Spain.
| | - Luis J Corcuera
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Chile.
| | - León A Bravo
- Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agronómicas y Forestales, Universidad de La Frontera, Chile; Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Chile.
| |
Collapse
|
20
|
Raanan H, Oren N, Treves H, Berkowicz SM, Hagemann M, Pade N, Keren N, Kaplan A. Simulated soil crust conditions in a chamber system provide new insights on cyanobacterial acclimation to desiccation. Environ Microbiol 2015; 18:414-26. [PMID: 26234786 DOI: 10.1111/1462-2920.12998] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Environmental research often faces two major hurdles: (i) fluctuating spatial and temporal conditions and consequently large variability in the organisms' abundance and performance, and (ii) complex, costly logistics involved in field experiments. Measurements of physiological parameters or molecular analyses often represent single shot experiments. To study desiccation acclimation of filamentous cyanobacteria, the founders and main primary producers in desert biological soil crusts (BSC), we constructed an environmental chamber that can reproducibly and accurately simulate ambient conditions and measure microorganism performance. We show that recovery from desiccation of BSC cyanobacteria and Leptolyngbya ohadii isolated thereof are strongly affected by dehydration rate following morning dew. This effect is most pronounced in cells exposed to high light and temperature in the dry phase. Simultaneous measurements of water content, gas exchange and fluorescence were performed during dehydration. Photosynthetic performance measured by fluorescence begins declining when light intensity reaches values above 100 μmol photons m(-2) s(-1), even in fully hydrated cells. In contrast, photosynthetic rates measured using O2 evolution and CO2 uptake increased during rising irradiance to the point where the water content declined below ∼ 50%. Thus, fluorescence cannot serve as a reliable measure of photosynthesis in desert cyanobacteria. The effects of drying on gas exchange are discussed.
Collapse
Affiliation(s)
- Hagai Raanan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Nadav Oren
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Haim Treves
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Simon M Berkowicz
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.,Arid Ecosystems Research Center, Edmond J. Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Martin Hagemann
- Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, Rostock, D-18059, Germany
| | - Nadin Pade
- Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, Rostock, D-18059, Germany
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.,Arid Ecosystems Research Center, Edmond J. Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| |
Collapse
|
21
|
Candotto Carniel F, Zanelli D, Bertuzzi S, Tretiach M. Desiccation tolerance and lichenization: a case study with the aeroterrestrial microalga Trebouxia sp. (Chlorophyta). PLANTA 2015; 242:493-505. [PMID: 25998523 DOI: 10.1007/s00425-015-2319-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 05/04/2015] [Indexed: 06/04/2023]
Abstract
A comparative study of isolated vs. lichenized Trebouxia sp. showed that lichenization does not influence the survival capability of the alga to the photo-oxidative stress derived from prolonged desiccation. Coccoid algae in the Trebouxia genus are the most common photobionts of chlorolichens but are only sporadically found in soil or bark outside of a lichen. They all appear to be desiccation tolerant, i.e. they can survive drying to water contents of below 10%. However, little is known about their longevity in the dry state and to which extent lichenization can influence it. Here, we studied the longevity in the dry state of the lichenized alga (LT) Trebouxia sp. in the lichen Parmotrema perlatum, in comparison with axenically grown cultures (CT) isolated from the same lichen. We report on chlorophyll fluorescence emission and reactive oxygen species (ROS) production before desiccation, after 15-45 days in the dry state under different combinations of light and air humidity and after recovery for 1 or 3 days in fully hydrated conditions. Both the CT and the LT were able to withstand desiccation under high light (120 µmol photons m(-2) s(-1) for 14 h per day), but upon recovery after 45 days in the dry state the performance of the CT was better than that of the LT. By contrast, the quenching of excess light energy was more efficient in the LT, at high relative humidities especially. ROS production in the LT was influenced mostly by light exposure, whereas the CT showed an oxidative burst independent of the light conditions. Although lichenization provides benefits that are essential for the survival of the photobiont in high-light habitats, Trebouxia sp. can withstand protracted periods of photo-oxidative stress even outside of a lichen thallus.
Collapse
Affiliation(s)
- Fabio Candotto Carniel
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via L. Giorgieri, 10, 34127, Trieste, Italy,
| | | | | | | |
Collapse
|
22
|
Sadowsky A, Ott S. Symbiosis as a successful strategy in continental Antarctica: performance and protection of Trebouxia photosystem II in relation to lichen pigmentation. Polar Biol 2015. [DOI: 10.1007/s00300-015-1677-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
23
|
Slavov C, Reus M, Holzwarth AR. Two different mechanisms cooperate in the desiccation-induced excited state quenching in Parmelia lichen. J Phys Chem B 2013; 117:11326-36. [PMID: 23841476 DOI: 10.1021/jp402881f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The highly efficient desiccation-induced quenching in the poikilohydric lichen Parmelia sulcata has been studied by ultrafast fluorescence spectroscopy at room temperature (r.t.) and cryogenic temperatures in order to elucidate the quenching mechanism(s) and kinetic reaction models. Analysis of the r.t. data by kinetic target analysis reveals that two different quenching mechanisms contribute to the protection of photosystem II (PS II). The first mechanism is a direct quenching of the PS II antenna and is related to the characteristic F740 nm fluorescence band. Based on the temperature dependence of its spectra and the kinetics, this mechanism is proposed to reflect the formation of a fluorescent (F740) chlorophyll-chlorophyll charge-transfer state. It is discussed in relation to a similar fluorescence band and quenching mechanism observed in light-induced nonphotochemical quenching in higher plants. The second and more efficient quenching process (providing more than 70% of the total PS II quenching) is shown to involve an efficient spillover (energy transfer) from PS II to PS I which can be prevented by a short glutaraldehyde treatment. Desiccation causes a thylakoid-membrane rearrangement which brings into direct contact the PS II and PS I units. The energy transferred to PS I in the spillover process is then quenched highly efficiently in PS I due to the formation of a long-lived P700(+) state in the dried state in the light. As a consequence, both PS II and PS I are protected very efficiently against photodestruction. This dual quenching mechanism is supported by the low temperature kinetics data.
Collapse
Affiliation(s)
- Chavdar Slavov
- Max Planck Institute for Chemical Energy Conversion , D-45470 Mülheim a.d. Ruhr, Germany
| | | | | |
Collapse
|
24
|
Treves H, Raanan H, Finkel OM, Berkowicz SM, Keren N, Shotland Y, Kaplan A. A newly isolatedChlorellasp. from desert sand crusts exhibits a unique resistance to excess light intensity. FEMS Microbiol Ecol 2013; 86:373-80. [DOI: 10.1111/1574-6941.12162] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/05/2013] [Accepted: 06/11/2013] [Indexed: 12/13/2022] Open
Affiliation(s)
- Haim Treves
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| | - Hagai Raanan
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| | - Omri M. Finkel
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| | - Simon M. Berkowicz
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| | - Yoram Shotland
- Chemical Engineering; Shamoon College of Engineering; Beer Sheva Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus - Givat Ram; The Hebrew University of Jerusalem; Jerusalem Israel
| |
Collapse
|
25
|
Yamakawa H, Itoh S. Dissipation of excess excitation energy by drought-induced nonphotochemical quenching in two species of drought-tolerant moss: desiccation-induced acceleration of photosystem II fluorescence decay. Biochemistry 2013; 52:4451-9. [PMID: 23750703 DOI: 10.1021/bi4001886] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Drought-tolerant mosses survive with their green color intact even after long periods of dehydration that would kill ordinary plants. The mechanism of dissipation of excitation energy under drought stress was studied in two species of drought-tolerant moss, Rhytidium rugosum and Ceratodon purpureus. They showed severe quenching of photosystem II chlorophyll fluorescence (PSII) after being dehydrated in the dark. Quenching was induced by the acceleration of the fluorescence decay rate. This drought-induced nonphotochemical quenching (designated d-NPQ) was fully reversed by rehydration. Global analysis of fluorescence decay at 77 K indicated rapid 46 ps transfer of excitation energy from the 680-690 nm PSII bands to a 710 nm band, and to 740-760 nm bands. The latter bands decayed to the ground state with the same time constant showing the rapid dissipation of excitation energy into heat. The quenching by d-NPQ in dry moss was stronger than that by PSII charge separation or nonphotochemical quenching (NPQ), which operates under hydrating conditions. Drought-tolerant mosses, thus, dissipate excess excitation energy into heat. The d-NPQ mechanism in moss resembles that reported in lichens, suggesting their common origin.
Collapse
Affiliation(s)
- Hisanori Yamakawa
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8602, Japan
| | | |
Collapse
|
26
|
Verhoeven AS. Recovery kinetics of photochemical efficiency in winter stressed conifers: the effects of growth light environment, extent of the season and species. PHYSIOLOGIA PLANTARUM 2013; 147:147-158. [PMID: 22575048 DOI: 10.1111/j.1399-3054.2012.01644.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Evergreens undergo reductions in maximal photochemical efficiency (F(v)/F(m)) during winter due to increases in sustained thermal energy dissipation. Upon removing winter stressed leaves to room temperature and low light, F(v)/F(m) recovers and can include both a rapid and a slow phase. The goal of this study was to determine whether the rapid component to recovery exists in winter stressed conifers at any point during the season in a seasonally extreme environment. Additional goals were to compare the effects of species, growth light environment and the extent of the winter season on recovery kinetics in conifers. Four species (sun and shade needle) were monitored during the winter of 2007/2008: eastern white pine (Pinus strobus), balsam fir (Abies balsamea), Taxus cuspidata and white spruce (Picea glauca). F(v)/F(m) was measured in the field, and then monitored indoors at room temperature and low light for 6 days. The results showed that all species showed a rapid component to recovery in early winter that disappeared later in the season in sun needles but was present in shade needles on most days monitored during winter. There were differences among species in the recovery kinetics across the season, with pine recovering the most slowly and spruce the most quickly. The results suggest an important role for the rapidly reversible form of energy dissipation in early winter, as well as important differences between species in their rate of recovery in late winter/early spring which may have implications for spring onset of photosynthesis.
Collapse
Affiliation(s)
- Amy S Verhoeven
- Biology Department, University of St. Thomas, St. Paul, MN 55105, USA.
| |
Collapse
|
27
|
Junttila S, Rudd S. Characterization of a transcriptome from a non-model organism, Cladonia rangiferina, the grey reindeer lichen, using high-throughput next generation sequencing and EST sequence data. BMC Genomics 2012; 13:575. [PMID: 23110403 PMCID: PMC3534622 DOI: 10.1186/1471-2164-13-575] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 10/11/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lichens are symbiotic organisms that have a remarkable ability to survive in some of the most extreme terrestrial climates on earth. Lichens can endure frequent desiccation and wetting cycles and are able to survive in a dehydrated molecular dormant state for decades at a time. Genetic resources have been established in lichen species for the study of molecular systematics and their taxonomic classification. No lichen species have been characterised yet using genomics and the molecular mechanisms underlying the lichen symbiosis and the fundamentals of desiccation tolerance remain undescribed. We report the characterisation of a transcriptome of the grey reindeer lichen, Cladonia rangiferina, using high-throughput next-generation transcriptome sequencing and traditional Sanger EST sequencing data. RESULTS Altogether 243,729 high quality sequence reads were de novo assembled into 16,204 contigs and 49,587 singletons. The genome of origin for the sequences produced was predicted using Eclat with sequences derived from the axenically grown symbiotic partners used as training sequences for the classification model. 62.8% of the sequences were classified as being of fungal origin while the remaining 37.2% were predicted as being of algal origin. The assembled sequences were annotated by BLASTX comparison against a non-redundant protein sequence database with 34.4% of the sequences having a BLAST match. 29.3% of the sequences had a Gene Ontology term match and 27.9% of the sequences had a domain or structural match following an InterPro search. 60 KEGG pathways with more than 10 associated sequences were identified. CONCLUSIONS Our results present a first transcriptome sequencing and de novo assembly for a lichen species and describe the ongoing molecular processes and the most active pathways in C. rangiferina. This brings a meaningful contribution to publicly available lichen sequence information. These data provide a first glimpse into the molecular nature of the lichen symbiosis and characterise the transcriptional space of this remarkable organism. These data will also enable further studies aimed at deciphering the genetic mechanisms behind lichen desiccation tolerance.
Collapse
Affiliation(s)
- Sini Junttila
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| | - Stephen Rudd
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Tykistökatu 6, 20520, Turku, Finland
| |
Collapse
|
28
|
Heber U. Conservation and dissipation of light energy in desiccation-tolerant photoautotrophs, two sides of the same coin. PHOTOSYNTHESIS RESEARCH 2012; 113:5-13. [PMID: 22527974 DOI: 10.1007/s11120-012-9738-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/20/2012] [Indexed: 05/31/2023]
Abstract
Conservation of light energy in photosynthesis is possible only in hydrated photoautotrophs. It requires complex biochemistry and is limited in capacity. Charge separation in reaction centres of photosystem II initiates energy conservation but opens also the path to photooxidative damage. A main mechanism of photoprotection active in hydrated photoautotrophs is controlled by light. This is achieved by coupling light flux to the protonation of a special thylakoid protein which activates thermal energy dissipation. This mechanism facilitates the simultaneous occurrence of energy conservation and energy dissipation but cannot completely prevent damage by light. Continuous metabolic repair is required to compensate damage. More efficient photoprotection is needed by desiccation-tolerant photoautotrophs. Loss of water during desiccation activates ultra-fast energy dissipation in mosses and lichens. Desiccation-induced energy dissipation neither requires a protonation reaction nor light but photoprotection often increases when light is present during desiccation. Two different mechanisms contribute to photoprotection of desiccated photoautotrophs. One facilitates energy dissipation in the antenna of photosystem II which is faster than energy capture by functional reaction centres. When this is insufficient for full photoprotection, the other one permits energy dissipation in the reaction centres themselves.
Collapse
Affiliation(s)
- Ulrich Heber
- Julius-von-Sachs-Institute, University of Würzburg, 97082, Würzburg, Germany.
| |
Collapse
|
29
|
García-Plazaola JI, Esteban R, Fernández-Marín B, Kranner I, Porcar-Castell A. Thermal energy dissipation and xanthophyll cycles beyond the Arabidopsis model. PHOTOSYNTHESIS RESEARCH 2012; 113:89-103. [PMID: 22772904 DOI: 10.1007/s11120-012-9760-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 06/18/2012] [Indexed: 05/20/2023]
Abstract
Thermal dissipation of excitation energy is a fundamental photoprotection mechanism in plants. Thermal energy dissipation is frequently estimated using the quenching of the chlorophyll fluorescence signal, termed non-photochemical quenching. Over the last two decades, great progress has been made in the understanding of the mechanism of thermal energy dissipation through the use of a few model plants, mainly Arabidopsis. Nonetheless, an emerging number of studies suggest that this model represents only one strategy among several different solutions for the environmental adjustment of thermal energy dissipation that have evolved among photosynthetic organisms in the course of evolution. In this review, a detailed analysis of three examples highlights the need to use models other than Arabidopsis: first, overwintering evergreens that develop a sustained form of thermal energy dissipation; second, desiccation tolerant plants that induce rapid thermal energy dissipation; and third, understorey plants in which a complementary lutein epoxide cycle modulates thermal energy dissipation. The three examples have in common a shift from a photosynthetically efficient state to a dissipative conformation, a strategy widely distributed among stress-tolerant evergreen perennials. Likewise, they show a distinct operation of the xanthophyll cycle. Expanding the list of model species beyond Arabidopsis will enhance our knowledge of these mechanisms and increase the synergy of the current studies now dispersed over a wide number of species.
Collapse
Affiliation(s)
- José Ignacio García-Plazaola
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Apdo 644, 48080, Bilbao, Spain.
| | | | | | | | | |
Collapse
|
30
|
Wieners PC, Mudimu O, Bilger W. Desiccation-induced non-radiative dissipation in isolated green lichen algae. PHOTOSYNTHESIS RESEARCH 2012; 113:239-247. [PMID: 22833109 DOI: 10.1007/s11120-012-9771-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 07/16/2012] [Indexed: 05/27/2023]
Abstract
Lichens are able to tolerate almost complete desiccation and can quickly resume metabolic activity after rehydration. In the desiccated state, photosynthesis is completely blocked and absorbed excitation energy cannot be used for electron transport, leading to a potential strong vulnerability for high light damage. Although desiccation and high insolation often occur simultaneously and many lichens colonize exposed habitats, these organisms show surprisingly little photodamage. In the desiccated state, variable chlorophyll fluorescence is lost, indicating a suspension of charge separation in photosystem II. At the same time, basal fluorescence (F (0)) is strongly quenched, which has been interpreted as an indication for high photoprotective non-radiative dissipation (NRD) of absorbed excitation energy. In an attempt to provide evidence for a photoprotective function of NRD in the desiccated state, isolated green lichen algae of the species Coccomyxa sp. and Trebouxia asymmetrica were used as experimental system. In contrast to experiments with intact lichens this system provided high reproducibility of the data without major optical artifacts on desiccation. The presence of 5 mM trehalose during desiccation had no effect but culture of the algae in seawater enhanced F (0) quenching in T. asymmetrica together with a reduced depression of F (V)/F (M) after high light treatment. While this effect could not be induced using artificial seawater medium lacking trace elements, the addition of ZnCl(2) and NaI in small amounts to the normal growth medium led to qualitatively and quantitatively identical results as with pure seawater. It is concluded that NRD indicated by F (0) quenching is photoprotective. The formation of NRD in lichen algae is apparently partially dependent on the presence of specific micronutrients.
Collapse
Affiliation(s)
- Paul Christian Wieners
- Botanical Institute, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098, Kiel, Germany
| | | | | |
Collapse
|
31
|
Miralles I, Jorge-Villar SE, Cantón Y, Domingo F. Using a mini-Raman spectrometer to monitor the adaptive strategies of extremophile colonizers in arid deserts: relationships between signal strength, adaptive strategies, solar radiation, and humidity. ASTROBIOLOGY 2012; 12:743-753. [PMID: 22970864 DOI: 10.1089/ast.2011.0763] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The survival strategies of one cyanobacteria colony and three terricolous lichen species from the hot subdesert of Tabernas, Spain, were studied along with topographical attributes of the area to investigate whether the protective strategies adopted by these pioneer soil colonizers are related to the environmental stressors under which they survive. A handheld Raman spectrometer was used for biomolecular characterization, while the microclimatic and topographic parameters were estimated with a Geographic Information System (GIS). We found that the survival strategies adopted by those organisms are based on different combinations of protective biomolecules, each with diverse ecophysiological functions, such as UV-radiation screening, free-energy quenching, antioxidants, and the production of different types and amounts of calcium oxalates. Our results show that the cyanobacteria community and each lichen species preferentially colonized a particular microhabitat with specific moisture and incident solar radiation levels and exhibited different adaptive mechanisms. In recent years, a number of studies have provided consistent results that suggest a link between the strategies adopted by those extremophile organisms and the microclimatic environmental parameters. To date, however, far too little attention has been paid to results from Raman analyses on dry specimens. Therefore, the results of the present study, produced with the use of our miniaturized instrument, will be of interest to future studies in astrobiology, especially due to the likely use of Raman spectroscopy at the surface of Mars.
Collapse
Affiliation(s)
- I Miralles
- Experimental Station of Arid Zones (CSIC), Almería, Spain.
| | | | | | | |
Collapse
|
32
|
Yamakawa H, Fukushima Y, Itoh S, Heber U. Three different mechanisms of energy dissipation of a desiccation-tolerant moss serve one common purpose: to protect reaction centres against photo-oxidation. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3765-75. [PMID: 22438303 PMCID: PMC3388843 DOI: 10.1093/jxb/ers062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Three different types of non-photochemical de-excitation of absorbed light energy protect photosystem II of the sun- and desiccation-tolerant moss Rhytidium rugosum against photo-oxidation. The first mechanism, which is light-induced in hydrated thalli, is sensitive to inhibition by dithiothreitol. It is controlled by the protonation of a thylakoid protein. Other mechanisms are activated by desiccation. One of them permits exciton migration towards a far-red band in the antenna pigments where fast thermal deactivation takes place. This mechanism appears to be similar to a mechanism detected before in desiccated lichens. A third mechanism is based on the reversible photo-accumulation of a radical that acts as a quencher of excitation energy in reaction centres of photosystem II. On the basis of absorption changes around 800 nm, the quencher is suggested to be an oxidized chlorophyll. The data show that desiccated moss is better protected against photo-oxidative damage than hydrated moss. Slow drying of moss thalli in the light increases photo-protection more than slow drying in darkness.
Collapse
Affiliation(s)
- Hisanori Yamakawa
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464–8602, Japan
| | - Yoshimasa Fukushima
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464–8602, Japan
| | - Shigeru Itoh
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464–8602, Japan
- To whom correspondence should be addressed. E-mail: ,
| | - Ulrich Heber
- Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, D-97082 Würzburg, Germany
- To whom correspondence should be addressed. E-mail: ,
| |
Collapse
|
33
|
Yang RL, Zhou W, Shen SD, Wang GC, He LW, Pan GH. Morphological and photosynthetic variations in the process of spermatia formation from vegetative cells in Porphyra yezoensis Ueda (Bangiales, Rhodophyta) and their responses to desiccation. PLANTA 2012; 235:885-893. [PMID: 22101945 DOI: 10.1007/s00425-011-1549-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Accepted: 11/04/2011] [Indexed: 05/31/2023]
Abstract
Porphyra yezoensis has a macroscopic foliage gametophyte phase with only a single cell layer, and is ideally suited for the study of the sexual differentiation process, from the vegetative cell to the spermatia. Firstly, we compared variations in the responses of the vegetative and male sectors to desiccation. Later, cell tracking experiments were carried out during the formation of spermatia from vegetative cells. The two sectors showed similar tolerance to desiccation, and the formation of spermatia from vegetative cells was independent of the degree of desiccation. Both light and scanning electron microscopy (SEM) observations of the differentiation process showed that the formation of spermatia could be divided into six phases: the one-cell, two-cell, four-cell, eight-cell, pre-release and spermatia phases. Photomicrographs of Fluorescent Brightener staining showed that the released spermatia had no cell walls. Photosynthetic data showed that there was a significant rise in Y(II) in the four-cell phase, indicating an increase in photosynthetic efficiency of PSII during this phase. We propose that this photosynthetic rise may be substantial and provide the increased energy needed for the formation and release of spermatia in P. yezoensis.
Collapse
Affiliation(s)
- Rui-Ling Yang
- College of Marine Science and Engineering, Tianjin University of Science & Technology, 300457, Tianjin, China
| | | | | | | | | | | |
Collapse
|
34
|
Heber U. From horse thief to professor: confessions of a plant physiologist. PHOTOSYNTHESIS RESEARCH 2012; 112:1-12. [PMID: 22399437 DOI: 10.1007/s11120-012-9725-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 02/03/2012] [Indexed: 05/31/2023]
Abstract
Can 50 years of research, performed between ignorance and the wish to know, and executed between hope, despair, satisfaction and pain, be compressed into an abstract? What has been done in more than 50 years may be expressed in four words: it was worth it. If I had another life, I would do it again. In the beginning of my career, life was an enigma. It still is. Molecular details of the workings of life had been largely unknown when I began. Now, at the end, I still wish to know details: how is light, master of life, manipulated to either support life, when photosynthesis is possible, or to protect it when light endangers it. What is the molecular and the physical nature of the biological mechanisms which control both, energy conservation and energy dissipation, in photosynthesis?
Collapse
Affiliation(s)
- Ulrich Heber
- Julius-von-Sachs-Institute, University of Würzburg, 97082 Würzburg, Germany.
| |
Collapse
|
35
|
Gerotto C, Alboresi A, Giacometti GM, Bassi R, Morosinotto T. Role of PSBS and LHCSR in Physcomitrella patens acclimation to high light and low temperature. PLANT, CELL & ENVIRONMENT 2011; 34:922-932. [PMID: 21332514 DOI: 10.1111/j.1365-3040.2011.02294.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Photosynthetic organisms respond to strong illumination by activating several photoprotection mechanisms. One of them, non-photochemical quenching (NPQ), consists in the thermal dissipation of energy absorbed in excess. In vascular plants NPQ relies on the activity of PSBS, whereas in the green algae Chlamydomonas reinhardtii it requires a different protein, LHCSR. The moss Physcomitrella patens is the only known organism in which both proteins are present and active in triggering NPQ, making this organism particularly interesting for the characterization of this protection mechanism. We analysed the acclimation of Physcomitrella to high light and low temperature, finding that these conditions induce an increase in NPQ correlated to overexpression of both PSBS and LHCSR. Mutants depleted of PSBS and/or LHCSR showed that modulation of their accumulation indeed determines NPQ amplitude. All mutants with impaired NPQ also showed enhanced photosensitivity when exposed to high light or low temperature, indicating that in this moss the fast-responding NPQ mechanism is also involved in long-term acclimation.
Collapse
Affiliation(s)
- Caterina Gerotto
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58 B, 35121 Padova, ItalyDipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Alessandro Alboresi
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58 B, 35121 Padova, ItalyDipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Giorgio M Giacometti
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58 B, 35121 Padova, ItalyDipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Roberto Bassi
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58 B, 35121 Padova, ItalyDipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Tomas Morosinotto
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58 B, 35121 Padova, ItalyDipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy
| |
Collapse
|
36
|
Heber U, Soni V, Strasser RJ. Photoprotection of reaction centers: thermal dissipation of absorbed light energy vs charge separation in lichens. PHYSIOLOGIA PLANTARUM 2011; 142:65-78. [PMID: 21029105 DOI: 10.1111/j.1399-3054.2010.01417.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
During desiccation, fluorescence emission and stable light-dependent charge separation in the reaction centers (RCs) of photosystem II (PSII) declined strongly in three different lichens: in Parmelia sulcata with an alga as the photobiont, in Peltigera neckeri with a cyanobacterium and in the tripartite lichen Lobaria pulmonaria. Most of the decline of fluorescence was caused by a decrease in the quantum efficiency of fluorescence emission. It indicated the activation of photoprotective thermal energy dissipation. Photochemical activity of the RCs was retained even after complete desiccation. It led to light-dependent absorption changes and found expression in reversible increases in fluorescence or in fluorescence quenching. Lowering the temperature changed the direction of fluorescence responses in P. sulcata. The observations are interpreted to show that reversible light-induced increases in fluorescence emission in desiccated lichens indicate the functionality of the RCs of PSII. Photoprotection is achieved by the drainage of light energy to dissipating centers outside the RCs before stable charge separation can take place. Reversible quenching of fluorescence by strong illumination is suggested to indicate the conversion of the RCs from energy conserving to energy dissipating units. This permits them to avoid photoinactivation. On hydration, re-conversion occurs to energy-conserving RCs.
Collapse
Affiliation(s)
- Ulrich Heber
- Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Würzburg 97082, Germany.
| | | | | |
Collapse
|
37
|
Li Y, Wang Z, Xu T, Tu W, Liu C, Zhang Y, Yang C. Reorganization of photosystem II is involved in the rapid photosynthetic recovery of desert moss Syntrichia caninervis upon rehydration. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:1390-7. [PMID: 20719403 DOI: 10.1016/j.jplph.2010.05.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 05/07/2010] [Accepted: 05/17/2010] [Indexed: 05/12/2023]
Abstract
The moss Syntrichia caninervis (S. caninervis) is one of the dominant species in biological soil crusts of deserts. It has long been the focus of scientific research because of its ecological value. Moreover, S. caninervis has a special significance in biogenesis research because it is characterized by its fast restoration of photosynthesis upon onset of rehydration of the desiccated organism. In order to study the mechanisms of rapid photosynthetic recovery in mosses upon rewatering, we investigated the kinetics of the recovery process of photosynthetic activity in photosystem (PS) II, with an indirect assessment of the photochemical processes based on chlorophyll (Chl) fluorescence measurements. Our results showed that recovery can be divided into two phases. The fast initial phase, completed within 3 min, was characterized by a quick increase in maximal quantum efficiency of PSII (F(v)/F(m)). Over 50% of the PSII activities, including excitation energy transfer, oxygen evolution, charge separation, and electron transport, recovered within 0.5 min after rehydration. The second, slow phase was dominated by the increase of plastoquinone (PQ) reduction and the equilibrium of the energy transport from the inner antenna to the reaction center (RC) of PSII. Analysis of the recovery process in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) revealed that blocking the electron transport from Q(A) to Q(B) did not hamper Chl synthesis or Chl organization in thylakoid membranes under light conditions. A de novo chloroplast protein synthesis was not necessary for the initial recovery of photochemical activity in PSII. In conclusion, the moss's ability for rapid recovery upon rehydration is related to Chl synthesis, quick structural reorganization of PSII, and fast restoration of PSII activity without de novo chloroplast protein synthesis.
Collapse
Affiliation(s)
- Yang Li
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | | | | | | | | | | | | |
Collapse
|
38
|
Lüttge U, Büdel B. Resurrection kinetics of photosynthesis in desiccation-tolerant terrestrial green algae (Chlorophyta) on tree bark. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:437-444. [PMID: 20522179 DOI: 10.1111/j.1438-8677.2009.00249.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The rough bark of orchard trees (Malus) around Darmstadt is predominantly covered in red to purple-brown layers (biofilms) of epiphytic terrestrial alga of Trentepohlia umbrina. The smooth bark of forest trees (Fagus sylvatica L. and Acer sp.) in the same area is covered by bright green biofilms composed of the green algae Desmococcus, Apatococcus and Trebouxia, with a few cells of Coccomyxa and 'Chlorella' trebouxioides between them. These algae are desiccation tolerant. After samples of bark with the biofilms were kept in dry air in darkness for various periods of time, potential quantum yield of PSII, F(v)/F(m), recovered during rehydration upon rewetting. The kinetics and degree of recovery depended on the length of time that the algae were kept in dry air in the desiccated state. Recovery was better for green biofilm samples, i.e. quite good even after 80 days of desiccation (F(v)/F(m) = ca. 50% of initial value), than the red samples, where recovery was only adequate up to ca. 30-40 days of desiccation (F(v)/F(m) = ca. 20-55% of initial value). It is concluded that the different bark types constitute different ecophysiological niches that can be occupied by the algae and that can be distinguished by their capacity to recover from desiccation after different times in the dry state.
Collapse
Affiliation(s)
- U Lüttge
- Institut für Botanik, Technische Universität Darmstadt, Darmstadt, Germany
| | | |
Collapse
|
39
|
Strasser RJ, Tsimilli-Michael M, Qiang S, Goltsev V. Simultaneous in vivo recording of prompt and delayed fluorescence and 820-nm reflection changes during drying and after rehydration of the resurrection plant Haberlea rhodopensis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1313-26. [PMID: 20226756 DOI: 10.1016/j.bbabio.2010.03.008] [Citation(s) in RCA: 247] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 02/18/2010] [Accepted: 03/04/2010] [Indexed: 10/19/2022]
Abstract
A new instrument (M-PEA), which measures simultaneously kinetics of prompt fluorescence (PF), delayed fluorescence (DF) and modulated light reflection at 820nm (MR), was used to screen dark-adapted leaves of the resurrection plant Haberlea rhodopensis during their progressive drying, down to 1% relative water content (RWC), and after their re-watering. This is the first investigation using M-PEA, which employs alternations of actinic light (627-nm peak, 5000 micromol photons m(-2) s(-1)) and dark intervals, where PF-MR and DF kinetics are respectively recorded, with the added advantages: (a) all kinetics are recorded with high time resolution (starting from 0.01 ms), (b) the dark intervals' duration can be as short as 0.1 ms, (c) actinic illumination can be interrupted at different times during the PF transient (recorded up to 300 s), with the earliest interruption at 0.3 ms. Analysis of the simultaneous measurements at different water-content-states of H. rhodopensis leaves allowed the comparison and correlation of complementary information on the structure/function of the photosynthetic machinery, which is not destroyed but only inactivated (reversibly) at different degrees; the comparison and correlation helped also to test current interpretations of each signal and advance their understanding. Our results suggest that the desiccation tolerance of the photosynthetic machinery in H. rhodopensis is mainly based on mechanism(s) that lead to inactivation of photosystem II reaction centres (transformation to heat sinks), triggered already by a small RWC decrease.
Collapse
Affiliation(s)
- Reto J Strasser
- Weed Research Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | | | | | | |
Collapse
|
40
|
Heber U, Bilger W, Türk R, Lange OL. Photoprotection of reaction centres in photosynthetic organisms: mechanisms of thermal energy dissipation in desiccated thalli of the lichen Lobaria pulmonaria. THE NEW PHYTOLOGIST 2010; 185:459-70. [PMID: 19863730 DOI: 10.1111/j.1469-8137.2009.03064.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
*The photobionts of lichens have previously been shown to reversibly inactivate their photosystem II (PSII) upon desiccation, presumably as a photoprotective mechanism. The mechanism and the consequences of this process have been investigated in the green algal lichen Lobaria pulmonaria. *Lichen thalli were collected from a shaded and a sun-exposed site. The activation of PSII was followed by chlorophyll fluorescence measurements. *Inactivation of PSII, as indicated by the total loss of variable fluorescence, was accompanied by a strong decrease of basal fluorescence (F(0)). Sun-grown thalli, as well as thalli exposed to low irradiance during drying, showed a larger reduction of F(0) than shade-grown thalli or thalli desiccated in the dark. Desiccation increased phototolerance, which was positively correlated to enhanced quenching of F(0). Quenching of F(0) could be reversed by heating, and could be inhibited by glutaraldehyde but not by the uncoupler nigericin. *Activation of energy dissipation, apparent as F(0) quenching, is proposed to be based on an alteration in the conformation of a pigment protein complex. This permits thermal energy dissipation and gives considerable flexibility to photoprotection. Zeaxanthin formation apparently did not contribute to the enhancement of photoprotection by desiccation in the light. Light-induced absorbance changes indicated the involvement of chlorophyll and carotenoid cation radicals.
Collapse
Affiliation(s)
- Ulrich Heber
- Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, D-97082 Würzburg, Germany
| | | | | | | |
Collapse
|
41
|
Gasulla F, de Nova PG, Esteban-Carrasco A, Zapata JM, Barreno E, Guéra A. Dehydration rate and time of desiccation affect recovery of the lichen alga [corrected] Trebouxia erici: alternative and classical protective mechanisms. PLANTA 2009; 231:195-208. [PMID: 19774392 DOI: 10.1007/s00425-009-1019-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 08/19/2009] [Indexed: 05/27/2023]
Abstract
The mechanisms involved in desiccation tolerance of lichens and their photobionts are still poorly understood. To better understand these mechanisms we have studied dehydration rate and desiccation time in Trebouxia, the most abundant chlorophytic photobiont in lichen. Our findings indicate that the drying rate has a profound effect on the recovery of photosynthetic activity of algae after rehydration, greater than the effects of desiccation duration. The basal fluorescence (F'(o)) values in desiccated algae were significantly higher after rapid dehydration, than after slow dehydration, suggesting higher levels of light energy dissipation in slow-dried algae. Higher values of PSII electron transport were recovered after rehydration of slow-dried Trebouxia erici compared to rapid-dried algae. The main component of non-photochemical quenching after slow dehydration was energy dependent (q (E)), whereas after fast dehydration it was photoinhibition (q (I)). Although q (E) seems to play a role during desiccation recovery, no significant variations were detected in the xanthophyll cycle components. Desiccation did not affect PSI functionality. Classical antioxidant activities like superoxide dismutase or peroxidase decreased during desiccation and early recovery. Dehydrins were detected in the lichen-forming algae T. erici and were constitutively expressed. There is probably a minimal period required to develop strategies which will facilitate transition to the desiccated state in this algae. In this process, the xanthophyll cycle and classical antioxidant mechanisms play a very limited role, if any. However, our results indicate that there is an alternative mechanism of light energy dissipation during desiccation, where activation is dependent on a sufficiently slow dehydration rate.
Collapse
Affiliation(s)
- Francisco Gasulla
- Dpto. de Botánica, Fac. de Biología, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, 46100, Burjassot, Valencia, Spain
| | | | | | | | | | | |
Collapse
|
42
|
Fernández-Marín B, Balaguer L, Esteban R, Becerril JM, García-Plazaola JI. Dark induction of the photoprotective xanthophyll cycle in response to dehydration. JOURNAL OF PLANT PHYSIOLOGY 2009; 166:1734-44. [PMID: 19539398 DOI: 10.1016/j.jplph.2009.04.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 04/22/2009] [Accepted: 04/22/2009] [Indexed: 05/07/2023]
Abstract
Some plants tolerate tissue dehydration. Dehydration conditions suppress photosynthesis, exacerbating photooxidative stress. In this study, fern samples were collected from the field, desiccated in darkness, and subsequently re-watered. During dark dehydration, zeaxanthin (Z) was formed and maximal photochemical efficiency of PS II was strongly reduced. Rehydration in the dark reversed these effects. Violaxanthin de-epoxidase was responsible for the dark formation of Z as illustrated by its complete inhibition by DTT. Nonetheless, its activity was not affected by nigericin, indicating that Z formation in the dark could be a process independent of the transmembrane pH-gradient into the thylakoids. Synthesis de novo of Z was rejected after blocking carotenogenesis with norfluorazon. Dark formation of Z was also observed in dehydrating leaves of desiccation-intolerant plants, which seems to indicate that this is a phenomenon scattered among different taxa within the plant kingdom. Plants may trigger this mechanism during dehydration, for chlorophyll protection during desiccation, and for faster acclimation when rehydrating conditions return. Violaxanthin de-epoxidation to form Z is typically a light-dependent process, but the formation induced solely by dehydration might represent an anticipatory mechanism for preventing early morning photodamage in desiccation-tolerant plants such as the fern Ceterach officinarum.
Collapse
|