1
|
Zotz G, Andrade JL, Einzmann HJR. CAM plants: their importance in epiphyte communities and prospects with global change. ANNALS OF BOTANY 2023; 132:685-698. [PMID: 36617243 PMCID: PMC10799991 DOI: 10.1093/aob/mcac158] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND SCOPE The epiphytic life form characterizes almost 10 % of all vascular plants. Defined by structural dependence throughout their life and their non-parasitic relationship with the host, the term epiphyte describes a heterogeneous and taxonomically diverse group of plants. This article reviews the importance of crassulacean acid metabolism (CAM) among epiphytes in current climatic conditions and explores the prospects under global change. RESULTS AND CONCLUSIONS We question the view of a disproportionate importance of CAM among epiphytes and its role as a 'key innovation' for epiphytism but do identify ecological conditions in which epiphytic existence seems to be contingent on the presence of this photosynthetic pathway. Possibly divergent responses of CAM and C3 epiphytes to future changes in climate and land use are discussed with the help of experimental evidence, current distributional patterns and the results of several long-term descriptive community studies. The results and their interpretation aim to stimulate a fruitful discussion on the role of CAM in epiphytes in current climatic conditions and in altered climatic conditions in the future.
Collapse
Affiliation(s)
- Gerhard Zotz
- Functional Ecology Group, Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Box 5634, D-26046 Oldenburg, Germany
- Smithsonian Tropical Research Institute, Box 0843-03092, Panama, Republic of Panama
| | - José Luis Andrade
- Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Chuburná de Hidalgo, Mérida, Yucatán, Mexico
| | - Helena J R Einzmann
- Functional Ecology Group, Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Box 5634, D-26046 Oldenburg, Germany
| |
Collapse
|
2
|
Sage RF, Gilman IS, Smith JAC, Silvera K, Edwards EJ. Atmospheric CO2 decline and the timing of CAM plant evolution. ANNALS OF BOTANY 2023; 132:753-770. [PMID: 37642245 PMCID: PMC10799994 DOI: 10.1093/aob/mcad122] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/19/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
BACKGROUND AND AIMS CAM photosynthesis is hypothesized to have evolved in atmospheres of low CO2 concentration in recent geological time because of its ability to concentrate CO2 around Rubisco and boost water use efficiency relative to C3 photosynthesis. We assess this hypothesis by compiling estimates of when CAM clades arose using phylogenetic chronograms for 73 CAM clades. We further consider evidence of how atmospheric CO2 affects CAM relative to C3 photosynthesis. RESULTS Where CAM origins can be inferred, strong CAM is estimated to have appeared in the past 30 million years in 46 of 48 examined clades, after atmospheric CO2 had declined from high (near 800 ppm) to lower (<450 ppm) values. In turn, 21 of 25 clades containing CAM species (but where CAM origins are less certain) also arose in the past 30 million years. In these clades, CAM is probably younger than the clade origin. We found evidence for repeated weak CAM evolution during the higher CO2 conditions before 30 million years ago, and possible strong CAM origins in the Crassulaceae during the Cretaceous period prior to atmospheric CO2 decline. Most CAM-specific clades arose in the past 15 million years, in a similar pattern observed for origins of C4 clades. CONCLUSIONS The evidence indicates strong CAM repeatedly evolved in reduced CO2 conditions of the past 30 million years. Weaker CAM can pre-date low CO2 and, in the Crassulaceae, strong CAM may also have arisen in water-limited microsites under relatively high CO2. Experimental evidence from extant CAM species demonstrates that elevated CO2 reduces the importance of nocturnal CO2 fixation by increasing the contribution of C3 photosynthesis to daily carbon gain. Thus, the advantage of strong CAM would be reduced in high CO2, such that its evolution appears less likely and restricted to more extreme environments than possible in low CO2.
Collapse
Affiliation(s)
- Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Ian S Gilman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA
| | - J Andrew C Smith
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Katia Silvera
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA
| |
Collapse
|
3
|
Wiland-Szymańska J, Kazimierczak-Grygiel E, Drapikowski P, Borowiak K, Drapikowska M. Does a gender of Welwitschia mirabilis plants influence their photosynthetic activity? PLoS One 2023; 18:e0291122. [PMID: 37682874 PMCID: PMC10490862 DOI: 10.1371/journal.pone.0291122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Welwitschia mirabilis Hook.f. (Welwitschiaceae, Gnetales) is a gymnosperm plant unique in its habit with an isolated taxonomic position. This species is dioecious, but no studies of its photosynthetic activity were conducted with examination of differences among male and female plants. To fill this gap, the day and night photosynthetic activity of male and female specimens of Welwitschia mirabilis cultivated in the botanical garden was studied in controlled conditions. Photosynthetic activity was studied using net photosynthetic rate (PN), stomatal conductance (gs) and intercellular CO2 concentration (Ci) parameters. Additionally, a normalized difference vegetation index (NDVI) was used to assess the condition among male and female plants in full sunlight. The studied Welwitschia plants revealed variability in photosynthetic activity both during the day and the night. The photosynthetic activity was low in the morning hours and higher in the afternoon. There is a difference in the photosynthetic activity during the night between sexes, being higher in female specimens. Stomatal density was evaluated separately for adaxial and abaxial leaf surfaces. Statistically significant differences in the stomatal density on abaxial and adaxial leaf surfaces were observed in both sexes, especially distinctive in female specimens. NDVI has revealed that there were weak differences between male and female plants.
Collapse
Affiliation(s)
- Justyna Wiland-Szymańska
- Department of Systematic and Environmental Botany, The Adam Mickiewicz University, Poznań, Poland
| | | | - Paweł Drapikowski
- Institute of Robotics and Machine Intelligence, Poznan University of Technology, Poznan, Poland
| | - Klaudia Borowiak
- The Department of Ecology and Environmental Protection of the Poznań University of Life Sciences, Poznań, Poland
| | - Maria Drapikowska
- The Department of Ecology and Environmental Protection of the Poznań University of Life Sciences, Poznań, Poland
| |
Collapse
|
4
|
Wang Y, Smith JAC, Zhu XG, Long SP. Rethinking the potential productivity of crassulacean acid metabolism by integrating metabolic dynamics with shoot architecture, using the example of Agave tequilana. THE NEW PHYTOLOGIST 2023; 239:2180-2196. [PMID: 37537720 DOI: 10.1111/nph.19128] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 06/04/2023] [Indexed: 08/05/2023]
Abstract
Terrestrial CAM plants typically occur in hot semiarid regions, yet can show high crop productivity under favorable conditions. To achieve a more mechanistic understanding of CAM plant productivity, a biochemical model of diel metabolism was developed and integrated with 3-D shoot morphology to predict the energetics of light interception and photosynthetic carbon assimilation. Using Agave tequilana as an example, this biochemical model faithfully simulated the four diel phases of CO2 and metabolite dynamics during the CAM rhythm. After capturing the 3-D form over an 8-yr production cycle, a ray-tracing method allowed the prediction of the light microclimate across all photosynthetic surfaces. Integration with the biochemical model thereby enabled the simulation of plant and stand carbon uptake over daily and annual courses. The theoretical maximum energy conversion efficiency of Agave spp. is calculated at 0.045-0.049, up to 7% higher than for C3 photosynthesis. Actual light interception, and biochemical and anatomical limitations, reduced this to 0.0069, or 15.6 Mg ha-1 yr-1 dry mass annualized over an 8-yr cropping cycle, consistent with observation. This is comparable to the productivity of many C3 crops, demonstrating the potential of CAM plants in climates where little else may be grown while indicating strategies that could raise their productivity.
Collapse
Affiliation(s)
- Yu Wang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Dr., Urbana, IL, 61801, USA
| | - J Andrew C Smith
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Xin-Guang Zhu
- Key Laboratory for Plant Molecular Genetics, Center of Excellence for Molecular, Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Dr., Urbana, IL, 61801, USA
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
- Departments of Plant Biology and of Crop Sciences, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL, 61801, USA
| |
Collapse
|
5
|
Winter K. Ecophysiology of constitutive and facultative CAM photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6495-6508. [PMID: 30810162 DOI: 10.1093/jxb/erz002] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/08/2019] [Indexed: 05/24/2023]
Abstract
In plants exhibiting crassulacean acid metabolism (CAM), CAM photosynthesis almost always occurs together with C3 photosynthesis, and occasionally with C4 photosynthesis. Depending on species, ontogeny, and environment, CAM input to total carbon gain can vary from values of <1% to 100%. The wide range of CAM phenotypes between and within species is a fascinating example of functional diversity and plasticity, but poses a significant challenge when attempting to define CAM. CO2 gas exchange experiments designed for this review illustrate key patterns of CAM expression and highlight distinguishing features of constitutive and facultative CAM. Furthermore, they help to address frequently recurring questions on CAM terminology. The functional and evolutionary significance of contrasting CAM phenotypes and of intermediate states between extremes is discussed. Results from a study on nocturnal malate accumulation in 50 species of Aizoaceae exposed to drought and salinity stress suggest that facultative CAM is more widespread amongst vascular plants than previously thought.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, Balboa, Ancón, Republic of Panama
| |
Collapse
|
6
|
Tamayo‐Ordóñez MC, Ayil‐Gutiérrez BA, Tamayo‐Ordóñez YJ, Rodríguez‐Zapata LC, Monforte‐González M, De la Cruz‐Arguijo EA, García‐Castillo MJ, Sánchez‐Teyer LF. Review and in silico analysis of fermentation, bioenergy, fiber, and biopolymer genes of biotechnological interest in
Agave
L. for genetic improvement and biocatalysis. Biotechnol Prog 2018; 34:1314-1334. [DOI: 10.1002/btpr.2689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/04/2018] [Accepted: 06/26/2018] [Indexed: 12/17/2022]
Affiliation(s)
- M. C. Tamayo‐Ordóñez
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| | - B. A. Ayil‐Gutiérrez
- CONACYT‐ Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Blvd. del Maestro, s/n, Esq. Elías Piña Reynosa 88710 Mexico
| | - Y. J. Tamayo‐Ordóñez
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| | - L. C. Rodríguez‐Zapata
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| | - M. Monforte‐González
- Unidad de Bioquímica Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| | - E. A. De la Cruz‐Arguijo
- Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Blvd. del Maestro, s/n, Esq. Elías Piña Reynosa 88710 Mexico
| | - M. J. García‐Castillo
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| | - L. F. Sánchez‐Teyer
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Colonia Chuburná de Hidalgo, CP. 97200, Mérida Yucatán Mexico
| |
Collapse
|
7
|
Wagner K, Zotz G. Epiphytic bromeliads in a changing world: the effect of elevated CO 2 and varying water supply on growth and nutrient relations. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:636-640. [PMID: 29427326 DOI: 10.1111/plb.12708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Global climate change is likely to impact all plant life. Vascular epiphytes represent a life form that may be affected more than any other by possible changes in precipitation leading to water shortage, but negative effects of drought may be mitigated through increasing levels of atmospheric CO2 . We studied the response of three epiphytic Aechmea species to different CO2 and watering levels in a full-factorial climate chamber study over 100 days. All species use crassulacean acid metabolism (CAM). Response variables were relative growth rate (RGR), nocturnal acidification and foliar nutrient levels (N, P, K, Mg). Both elevated CO2 and increased water supply stimulated RGR, but the interaction of the two factors was not significant. Nocturnal acidification was not affected by these factors, indicating that the increase in growth in these CAM species was due to higher assimilation in the light. Mass-based foliar nutrient contents were consistently lower under elevated CO2 , but most differences disappeared when expressed on an area basis. Compared to previous studies with epiphytes, in which doubling of CO2 increased RGR, on average, by only 14%, these Aechmea species showed a relatively strong growth stimulation of up to +61%. Consistent with earlier findings with other bromeliads, elevated CO2 did not mitigate the effect of water shortage.
Collapse
Affiliation(s)
- K Wagner
- Institute for Biology and Environmental Sciences, AG Functional Ecology, Universität Oldenburg, Oldenburg, Germany
| | - G Zotz
- Institute for Biology and Environmental Sciences, AG Functional Ecology, Universität Oldenburg, Oldenburg, Germany
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panamá, República de Panamá
| |
Collapse
|
8
|
Berger J, Palta J, Vadez V. Review: An integrated framework for crop adaptation to dry environments: Responses to transient and terminal drought. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 253:58-67. [PMID: 27968997 DOI: 10.1016/j.plantsci.2016.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/16/2016] [Accepted: 09/20/2016] [Indexed: 05/09/2023]
Abstract
As the incidence of water deficit and heat stress increases in many production regions there is an increasing requirement for crops adapted to these stresses. Thus it is essential to match water supply and demand, particularly during grain-filling. Here we integrate Grime's ecological strategies approach with traditional drought resistance/yield component frameworks describing plant responses to water deficit. We demonstrate that water use is a function of both short and longer term trade-offs between competing demands for carbon. Agricultural crop adaptation is based on escape. Rapid growth rates and high reproductive investment maximize yield, and stress is avoided through a closely regulated, climate-appropriate annual phenology. Crops have neither the resources nor morphological capacity to withstand long periods of intense water deficit. Thus, under terminal drought, yield potential is traded off against drought escape, such that drought postponing and/or tolerance traits which extend the growing season and/or divert source from reproductive sinks are maladaptive. However, these traits do play a supporting role against transient water deficits, allowing longer season cultivars to survive by mining water through deeper roots, or restricting transpiration. Recognizing these trade-offs made within escape-strategy limits will allow breeders to integrate complementary adaptive traits to transient and terminal water deficits.
Collapse
Affiliation(s)
- Jens Berger
- CSIRO Agriculture, Private Bag No. 5, Wembley, WA 6913, Australia.
| | - Jairo Palta
- CSIRO Agriculture, Private Bag No. 5, Wembley, WA 6913, Australia
| | - Vincent Vadez
- ICRISAT, Crop Physiology Laboratory, Patancheru, 502 324 Telangana, India
| |
Collapse
|
9
|
Krause GH, Winter K, Krause B, Virgo A. Protection by light against heat stress in leaves of tropical crassulacean acid metabolism plants containing high acid levels. FUNCTIONAL PLANT BIOLOGY : FPB 2016; 43:1061-1069. [PMID: 32480526 DOI: 10.1071/fp16093] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/13/2016] [Indexed: 06/11/2023]
Abstract
Heat tolerance of plants exhibiting crassulacean acid metabolism (CAM) was determined by exposing leaf sections to a range of temperatures both in the dark and the light, followed by measuring chlorophyll a fluorescence (Fv/Fm and F0) and assessing visible tissue damage. Three CAM species, Clusia rosea Jacq., Clusia pratensis Seem. and Agave angustifolia Haw., were studied. In acidified tissues sampled at the end of the night and exposed to elevated temperatures in the dark, the temperature that caused a 50% decline of Fv/Fm (T50), was remarkably low (40-43°C in leaves of C. rosea). Conversion of chlorophyll to pheophytin indicated irreversible tissue damage caused by malic acid released from the vacuoles. By contrast, when acidified leaves were illuminated during heat treatments, T50 was up to 50-51°C. In de-acidified samples taken at the end of the light period, T50 reached ∼54°C, irrespective of whether temperature treatments were done in the dark or light. Acclimation of A. angustifolia to elevated daytime temperatures resulted in a rise of T50 from ∼54° to ∼57°C. In the field, high tissue temperatures always occur during sun exposure. Measurements of the heat tolerance of CAM plants that use heat treatments of acidified tissue in the dark do not provide relevant information on heat tolerance in an ecological context. However, in the physiological context, such studies may provide important clues on vacuolar properties during the CAM cycle (i.e. on the temperature relationships of malic acid storage and malic acid release).
Collapse
Affiliation(s)
- G Heinrich Krause
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama
| | - Barbara Krause
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama
| | - Aurelio Virgo
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama
| |
Collapse
|
10
|
Deng H, Zhang LS, Zhang GQ, Zheng BQ, Liu ZJ, Wang Y. Evolutionary history of PEPC genes in green plants: Implications for the evolution of CAM in orchids. Mol Phylogenet Evol 2016; 94:559-564. [DOI: 10.1016/j.ympev.2015.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 11/15/2022]
|