1
|
Siadjeu C, Kadereit G. C 4-like Sesuvium sesuvioides (Aizoaceae) exhibits CAM in cotyledons and putative C 4-like + CAM metabolism in adult leaves as revealed by transcriptome analysis. BMC Genomics 2024; 25:688. [PMID: 39003461 PMCID: PMC11245778 DOI: 10.1186/s12864-024-10553-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 06/21/2024] [Indexed: 07/15/2024] Open
Abstract
BACKGROUND The co-occurrence of C4 and CAM photosynthesis in a single species seems to be unusual and rare. This is likely due to the difficulty in effectively co-regulating both pathways. Here, we conducted a comparative transcriptomic analysis of leaves and cotyledons of the C4-like species Sesuvium sesuvioides (Aizoaceae) using RNA-seq. RESULTS When compared to cotyledons, phosphoenolpyruvate carboxylase 4 (PEPC4) and some key C4 genes were found to be up-regulated in leaves. During the day, the expression of NADP-dependent malic enzyme (NADP-ME) was significantly higher in cotyledons than in leaves. The titratable acidity confirmed higher acidity in the morning than in the previous evening indicating the induction of weak CAM in cotyledons by environmental conditions. Comparison of the leaves of S. sesuvioides (C4-like) and S. portulacastrum (C3) revealed that PEPC1 was significantly higher in S. sesuvioides, while PEPC3 and PEPC4 were up-regulated in S. portulacastrum. Finally, potential key regulatory elements involved in the C4-like and CAM pathways were identified. CONCLUSIONS These findings provide a new species in which C4-like and CAM co-occur and raise the question if this phenomenon is indeed so rare or just hard to detect and probably more common in succulent C4 lineages.
Collapse
Affiliation(s)
- Christian Siadjeu
- Prinzessin Therese von Bayern Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilans-Universität München, Menzinger Str. 67, Munich, 80638, Germany.
| | - Gudrun Kadereit
- Prinzessin Therese von Bayern Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilans-Universität München, Menzinger Str. 67, Munich, 80638, Germany
- Botanischer Garten München-Nymphenburg Und Botanische Staatssammlung München, Staatliche Naturwissenschaftliche Sammlungen Bayerns, Menzinger Str. 65, Munich, 80638, Germany
| |
Collapse
|
2
|
Gilman IS, Heyduk K, Maya-Lastra C, Hancock LP, Edwards EJ. Predicting photosynthetic pathway from anatomy using machine learning. THE NEW PHYTOLOGIST 2024; 242:1029-1042. [PMID: 38173400 DOI: 10.1111/nph.19488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/29/2023] [Indexed: 01/05/2024]
Abstract
Plants with Crassulacean acid metabolism (CAM) have long been associated with a specialized anatomy, including succulence and thick photosynthetic tissues. Firm, quantitative boundaries between non-CAM and CAM plants have yet to be established - if they indeed exist. Using novel computer vision software to measure anatomy, we combined new measurements with published data across flowering plants. We then used machine learning and phylogenetic comparative methods to investigate relationships between CAM and anatomy. We found significant differences in photosynthetic tissue anatomy between plants with differing CAM phenotypes. Machine learning-based classification was over 95% accurate in differentiating CAM from non-CAM anatomy, and had over 70% recall of distinct CAM phenotypes. Phylogenetic least squares regression and threshold analyses revealed that CAM evolution was significantly correlated with increased mesophyll cell size, thicker leaves, and decreased intercellular airspace. Our findings suggest that machine learning may be used to aid the discovery of new CAM species and that the evolutionary trajectory from non-CAM to strong, obligate CAM requires continual anatomical specialization.
Collapse
Affiliation(s)
- Ian S Gilman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
| | - Karolina Heyduk
- Department of Ecology and Evolutionary Biology, The University of Connecticut, Storrs, CT, 06269, USA
| | - Carlos Maya-Lastra
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
- Department of Biology, Angelo State University, San Angelo, TX, 76909, USA
| | - Lillian P Hancock
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| |
Collapse
|
3
|
Xia K, Wu Q, Yang Y, Liu Q, Wang Z, Zhao Z, Li J, He J, Chai S, Qiu S. Drought Stress Induced Different Response Mechanisms in Three Dendrobium Species under Different Photosynthetic Pathways. Int J Mol Sci 2024; 25:2731. [PMID: 38473979 DOI: 10.3390/ijms25052731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/16/2024] [Accepted: 02/24/2024] [Indexed: 03/14/2024] Open
Abstract
Many Dendrobium species, which hold a high status and value in traditional Chinese medicine, grow on barks and rocks in the wild, often encountering harsh environments and facing droughts. However, the molecular mechanisms underlying the shift in the photosynthetic pathway induced by drought remain unclear. To address this issue, three Dendrobium species with different photosynthetic pathways were selected for sequencing and transcriptome data analysis after drought treatment. The findings included 134.43 GB of sequencing data, with numerous Differentially Expressed Genes (DEGs) exhibiting different response mechanisms under drought stress. Gene Ontology (GO)-KEGG-based enrichment analysis of DEGs revealed that metabolic pathways contributed to drought tolerance and alterations in photosynthetic pathways. Phosphoenolpyruvate Carboxylase (PEPC) was subjected to phylogenetic tree construction, sequence alignment, and domain analysis. Under drought stress, variations were observed in the PEPC gene structure and expression among different Dendrobium species; the upregulation of Dc_gene2609 expression may be caused by dof-miR-384, which resulted in the shift from C3 photosynthesis to CAM, thereby improving drought tolerance in Dendrobium. This study revealed the expression patterns and roles of PEPC genes in enhancing plant drought tolerance and will provide an important basis for in-depth research on Dendrobium's adaptation mechanisms in arid environments.
Collapse
Affiliation(s)
- Ke Xia
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Qiaofen Wu
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Yanni Yang
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Qiao Liu
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Zaihua Wang
- Guangdong Provincial Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Zhiguo Zhao
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Jie Li
- Guangdong Provincial Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Jinxiang He
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Shengfeng Chai
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| | - Shuo Qiu
- Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences/Guangxi Key Laboratory of Plant Functional Phytochemicals and Sustainable Utilization, Guilin 541006, China
| |
Collapse
|
4
|
Gilman IS, Smith JAC, Holtum JAM, Sage RF, Silvera K, Winter K, Edwards EJ. The CAM lineages of planet Earth. ANNALS OF BOTANY 2023; 132:627-654. [PMID: 37698538 PMCID: PMC10799995 DOI: 10.1093/aob/mcad135] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/09/2023] [Accepted: 09/11/2023] [Indexed: 09/13/2023]
Abstract
BACKGROUND AND SCOPE The growth of experimental studies of crassulacean acid metabolism (CAM) in diverse plant clades, coupled with recent advances in molecular systematics, presents an opportunity to re-assess the phylogenetic distribution and diversity of species capable of CAM. It has been more than two decades since the last comprehensive lists of CAM taxa were published, and an updated survey of the occurrence and distribution of CAM taxa is needed to facilitate and guide future CAM research. We aimed to survey the phylogenetic distribution of these taxa, their diverse morphology, physiology and ecology, and the likely number of evolutionary origins of CAM based on currently known lineages. RESULTS AND CONCLUSIONS We found direct evidence (in the form of experimental or field observations of gas exchange, day-night fluctuations in organic acids, carbon isotope ratios and enzymatic activity) for CAM in 370 genera of vascular plants, representing 38 families. Further assumptions about the frequency of CAM species in CAM clades and the distribution of CAM in the Cactaceae and Crassulaceae bring the currently estimated number of CAM-capable species to nearly 7 % of all vascular plants. The phylogenetic distribution of these taxa suggests a minimum of 66 independent origins of CAM in vascular plants, possibly with dozens more. To achieve further insight into CAM origins, there is a need for more extensive and systematic surveys of previously unstudied lineages, particularly in living material to identify low-level CAM activity, and for denser sampling to increase phylogenetic resolution in CAM-evolving clades. This should allow further progress in understanding the functional significance of this pathway by integration with studies on the evolution and genomics of CAM in its many forms.
Collapse
Affiliation(s)
- Ian S Gilman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | | | - Joseph A M Holtum
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Katia Silvera
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panama
- Department of Botany & Plant Sciences, University of California, Riverside, CA, USA
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panama
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| |
Collapse
|
5
|
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
|
6
|
Yamaga-Hatakeyama Y, Okutani M, Hatakeyama Y, Yabiku T, Yukawa T, Ueno O. Photosynthesis and leaf structure of F1 hybrids between Cymbidium ensifolium (C3) and C. bicolor subsp. pubescens (CAM). ANNALS OF BOTANY 2023; 132:895-907. [PMID: 36579478 PMCID: PMC10799985 DOI: 10.1093/aob/mcac157] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/17/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS The introduction of crassulacean acid metabolism (CAM) into C3 crops has been considered as a means of improving water-use efficiency. In this study, we investigated photosynthetic and leaf structural traits in F1 hybrids between Cymbidium ensifolium (female C3 parent) and C. bicolor subsp. pubescens (male CAM parent) of the Orchidaceae. METHODS Seven F1 hybrids produced through artificial pollination and in vitro culture were grown in a greenhouse with the parent plants. Structural, biochemical and physiological traits involved in CAM in their leaves were investigated. KEY RESULTS Cymbidium ensifolium accumulated very low levels of malate without diel fluctuation, whereas C. bicolor subsp. pubescens showed nocturnal accumulation and diurnal consumption of malate. The F1s also accumulated malate at night, but much less than C. bicolor subsp. pubescens. This feature was consistent with low nocturnal fixation of atmospheric CO2 in the F1s. The δ13C values of the F1s were intermediate between those of the parents. Leaf thickness was thicker in C. bicolor subsp. pubescens than in C. ensifolium, and those of the F1s were more similar to that of C. ensifolium. This was due to the difference in mesophyll cell size. The chloroplast coverage of mesophyll cell perimeter adjacent to intercellular air spaces of C. bicolor subsp. pubescens was lower than that of C. ensifolium, and that of the F1s was intermediate between them. Interestingly, one F1 had structural and physiological traits more similar to those of C. bicolor subsp. pubescens than the other F1s. Nevertheless, all F1s contained intermediate levels of phosphoenolpyruvate carboxylase but as much pyruvate, Pi dikinase as C. bicolor subsp. pubescens. CONCLUSIONS CAM traits were intricately inherited in the F1 hybrids, the level of CAM expression varied widely among F1 plants, and the CAM traits examined were not necessarily co-ordinately transmitted to the F1s.
Collapse
Affiliation(s)
| | - Masamitsu Okutani
- School of Agriculture, Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yuto Hatakeyama
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takayuki Yabiku
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tomohisa Yukawa
- Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Ibaraki 305-0005, Japan
| | - Osamu Ueno
- Faculty of Agriculture, Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| |
Collapse
|
7
|
Holtum JAM. The diverse diaspora of CAM: a pole-to-pole sketch. ANNALS OF BOTANY 2023; 132:597-625. [PMID: 37303205 PMCID: PMC10800000 DOI: 10.1093/aob/mcad067] [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: 09/27/2022] [Revised: 12/13/2022] [Accepted: 06/09/2023] [Indexed: 06/13/2023]
Abstract
BACKGROUND Crassulacean acid metabolism (CAM) photosynthesis is a successful adaptation that has evolved often in angiosperms, gymnosperms, ferns and lycophytes. Present in ~5 % of vascular plants, the CAM diaspora includes all continents apart from Antarctica. Species with CAM inhabit most landscapes colonized by vascular plants, from the Arctic Circle to Tierra del Fuego, from below sea level to 4800 m a.s.l., from rainforests to deserts. They have colonized terrestrial, epiphytic, lithophytic, palustrine and aquatic systems, developing perennial, annual or geophyte strategies that can be structurally arborescent, shrub, forb, cladode, epiphyte, vine or leafless with photosynthetic roots. CAM can enhance survival by conserving water, trapping carbon, reducing carbon loss and/or via photoprotection. SCOPE This review assesses the phylogenetic diversity and historical biogeography of selected lineages with CAM, i.e. ferns, gymnosperms and eumagnoliids, Orchidaceae, Bromeliaceae, Crassulaceae, Euphorbiaceae, Aizoaceae, Portulacineae (Montiaceae, Basellaceae, Halophytaceae, Didiereaceae, Talinaceae, Portulacaceae, Anacampserotaceae and Cactaceae) and aquatics. CONCLUSIONS Most extant CAM lineages diversified after the Oligocene/Miocene, as the planet dried and CO2 concentrations dropped. Radiations exploited changing ecological landscapes, including Andean emergence, Panamanian Isthmus closure, Sundaland emergence and submergence, changing climates and desertification. Evidence remains sparse for or against theories that CAM biochemistry tends to evolve before pronounced changes in anatomy and that CAM tends to be a culminating xerophytic trait. In perennial taxa, any form of CAM can occur depending upon the lineage and the habitat, although facultative CAM appears uncommon in epiphytes. CAM annuals lack strong CAM. In CAM annuals, C3 + CAM predominates, and inducible or facultative CAM is common.
Collapse
Affiliation(s)
- Joseph A M Holtum
- College of Science and Engineering, James Cook University, Townsville, QLD4811, Australia
| |
Collapse
|
8
|
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
|
9
|
Eskov AK, Elumeeva TG, Leonov VD, Tsurikov SM, Viktorova VA, Prilepsky NG, Abakumov EV. The Carbon Isotope Composition of Epiphytes Depends Not Only on Their Layers, Life Forms, and Taxonomical Groups but Also on the Carbon and Nitrogen Indicators of Host Trees. PLANTS (BASEL, SWITZERLAND) 2023; 12:3500. [PMID: 37836240 PMCID: PMC10575002 DOI: 10.3390/plants12193500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 09/27/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023]
Abstract
The carbon isotopic composition of plant tissues is a diagnostic feature of a number of physiological and ecological processes. The most important of which is the type of photosynthesis. In epiphytes, two peaks of δ13C values are known to correspond to C3 and CAM photosynthesis and some variants of transitional forms between them. But the diagnosis of δ13C may not be limited to the type of photosynthesis. This makes it necessary to study trends in the distribution of δ13C in a broader ecological context. In this study, we present trends in the distribution of δ13C epiphytes and other structurally dependent plants and their relationship with other isotopic and elemental parameters (δ15N, C%, N%, and C/N) and with life forms of epiphytes, taxonomic or vertical groups in crowns (synusia), and the parameters of the trees themselves. In all communities except for the moss forest, δ13C in epiphyte leaves was significantly higher (less negative) than in phorophyte leaves. In general, δ13C in epiphytes in mountain communities (pine forest and moss forest) was more negative than in other communities due to the absence of succulents with CAM. δ13C in the leaves of all epiphytes was negatively related to the percentage of carbon and δ15N in the leaves of the phorophyte. When considering the Gaussian distributions of δ13C with the method of modeling mixtures, we observe the unimodal, bimodal, and trimodal nature of the distribution.
Collapse
Affiliation(s)
- Alen K. Eskov
- Department of Plant Ecology and Geography, Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Tatiana G. Elumeeva
- Department of Plant Ecology and Geography, Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Vlad. D. Leonov
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninskij Prosp., 119071 Moscow, Russia
| | - Sergey M. Tsurikov
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninskij Prosp., 119071 Moscow, Russia
| | | | - Nikolay G. Prilepsky
- Department of Plant Ecology and Geography, Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Evgeny V. Abakumov
- Department of Applied Ecology, Saint-Petersburg State University, 16 Line of VO 29, 199178 St. Petersburg, Russia;
| |
Collapse
|
10
|
Pérez-López AV, Lim SD, Cushman JC. Tissue succulence in plants: Carrying water for climate change. JOURNAL OF PLANT PHYSIOLOGY 2023; 289:154081. [PMID: 37703768 DOI: 10.1016/j.jplph.2023.154081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/01/2023] [Indexed: 09/15/2023]
Abstract
Tissue succulence in plants involves the storage of water in one or more organs or tissues to assist in maintaining water potentials on daily or seasonal time scales. This drought-avoidance or drought-resistance strategy allows plants to occupy diverse environments including arid regions, regions with rocky soils, epiphytic habitats, and saline soils. Climate-resilient strategies are of increasing interest in the context of the global climate crisis, which is leading to hotter and drier conditions in many regions throughout the globe. Here, we describe a short history of succulent plants, the basic concepts of tissue succulence, the anatomical diversity of succulent morphologies and associated adaptive traits, the evolutionary, phylogenetic, and biogeographical diversity of succulent plants, extinction risks to succulents due to poaching from their natural environments, and the myriad uses and applications of economically important succulent species and the products derived from them. Lastly, we discuss current prospects for engineering tissue succulence to improve salinity and drought tolerance in crops.
Collapse
Affiliation(s)
- Arely V Pérez-López
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557-0330, USA.
| | - Sung Don Lim
- Department of Plant Life and Resource Science, Sangji University, Gangwon-do, 26339, South Korea.
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557-0330, USA.
| |
Collapse
|
11
|
Schönbeck L, Arteaga M, Mirza H, Coleman M, Mitchell D, Huang X, Ortiz H, Santiago LS. Plant physiological indicators for optimizing conservation outcomes. CONSERVATION PHYSIOLOGY 2023; 11:coad073. [PMID: 37711583 PMCID: PMC10498484 DOI: 10.1093/conphys/coad073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 07/20/2023] [Accepted: 08/22/2023] [Indexed: 09/16/2023]
Abstract
Plant species of concern often occupy narrow habitat ranges, making climate change an outsized potential threat to their conservation and restoration. Understanding the physiological status of a species during stress has the potential to elucidate current risk and provide an outlook on population maintenance. However, the physiological status of a plant can be difficult to interpret without a reference point, such as the capacity to tolerate stress before loss of function, or mortality. We address the application of plant physiology to conservation biology by distinguishing between two physiological approaches that together determine plant status in relation to environmental conditions and evaluate the capacity to avoid stress-induced loss of function. Plant physiological status indices, such as instantaneous rates of photosynthetic gas exchange, describe the level of physiological activity in the plant and are indicative of physiological health. When such measurements are combined with a reference point that reflects the maximum value or environmental limits of a parameter, such as the temperature at which photosynthesis begins to decline due to high temperature stress, we can better diagnose the proximity to potentially damaging thresholds. Here, we review a collection of useful plant status and reference point measurements related to photosynthesis, water relations and mineral nutrition, which can contribute to plant conservation physiology. We propose that these measurements can serve as important additional information to more commonly used phenological and morphological parameters, as the proposed parameters will reveal early warning signals before they are visible. We discuss their implications in the context of changing temperature, water and nutrient supply.
Collapse
Affiliation(s)
- Leonie Schönbeck
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Marc Arteaga
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Humera Mirza
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Mitchell Coleman
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
- Tejon Ranch Conservancy, Frazier Park, CA 93225, USA
| | - Denise Mitchell
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Xinyi Huang
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Haile Ortiz
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Louis S Santiago
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092. Balboa, Ancon, Panama, Republic of Panama
| |
Collapse
|
12
|
Suetsugu K, Sugita R, Yoshihara A, Okada H, Akita K, Nagata N, Tanoi K, Kobayashi K. Aerial roots of the leafless epiphytic orchid Taeniophyllum are specialized for performing crassulacean acid metabolism photosynthesis. THE NEW PHYTOLOGIST 2023; 238:932-937. [PMID: 36788446 DOI: 10.1111/nph.18812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Kenji Suetsugu
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo, 657-8501, Japan
- The Institute for Advanced Research, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo, 657-8501, Japan
| | - Ryohei Sugita
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Radioisotope Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Akiko Yoshihara
- Department of Biology, Graduate School of Science, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Hidehito Okada
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, Hyogo, 657-8501, Japan
| | - Kae Akita
- Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, 112-8681, Japan
| | - Noriko Nagata
- Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, 112-8681, Japan
| | - Keitaro Tanoi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Koichi Kobayashi
- Department of Biology, Graduate School of Science, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| |
Collapse
|
13
|
Shen S, Li N, Wang Y, Zhou R, Sun P, Lin H, Chen W, Yu T, Liu Z, Wang Z, Tan X, Zhu C, Feng S, Zhang Y, Song X. High-quality ice plant reference genome analysis provides insights into genome evolution and allows exploration of genes involved in the transition from C3 to CAM pathways. PLANT BIOTECHNOLOGY JOURNAL 2022; 20:2107-2122. [PMID: 35838009 PMCID: PMC9616530 DOI: 10.1111/pbi.13892] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/19/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Ice plant (Mesembryanthemum crystallinum), a member of the Aizoaceae family, is a typical halophyte crop and a model plant for studying the mechanism of transition from C3 photosynthesis to crassulacean acid metabolism (CAM). Here, we report a high-quality chromosome-level ice plant genome sequence. This 98.05% genome sequence is anchored to nine chromosomes, with a total length of 377.97 Mb and an N50 scaffold of 40.45 Mb. Almost half of the genome (48.04%) is composed of repetitive sequences, and 24 234 genes have been annotated. Subsequent to the ancient whole-genome triplication (WGT) that occurred in eudicots, there has been no recent whole-genome duplication (WGD) or WGT in ice plants. However, we detected a novel WGT event that occurred in the same order in Simmondsia chinensis, which was previously overlooked. Our findings revealed that ice plants have undergone chromosome rearrangements and gene removal during evolution. Combined with transcriptome and comparative genomic data and expression verification, we identified several key genes involved in the CAM pathway and constructed a comprehensive network. As the first genome of the Aizoaceae family to be released, this report will provide a rich data resource for comparative and functional genomic studies of Aizoaceae, especially for studies on salt tolerance and C3-to-CAM transitions to improve crop yield and resistance.
Collapse
Affiliation(s)
- Shaoqin Shen
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Nan Li
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Yujie Wang
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Rong Zhou
- Department of Food ScienceAarhus UniversityAarhusDenmark
| | - Pengchuan Sun
- Key Laboratory for Bio‐Resource and Eco‐Environment of Ministry of Education, College of Life SciencesSichuan UniversityChengduChina
| | - Hao Lin
- School of Life Science and Technology and Center for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Wei Chen
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
- Innovative Institute of Chinese Medicine and PharmacyChengdu University of Traditional Chinese MedicineChengduChina
| | - Tong Yu
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Zhuo Liu
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Zhiyuan Wang
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Xiao Tan
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Changping Zhu
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Shuyan Feng
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Yu Zhang
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
| | - Xiaoming Song
- College of Life Sciences/Center for Genomics and Bio‐computingNorth China University of Science and TechnologyTangshanHebeiChina
- School of Life Science and Technology and Center for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
- Food Science and Technology DepartmentUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| |
Collapse
|
14
|
Rangan P, Wankhede DP, Subramani R, Chinnusamy V, Malik SK, Baig MJ, Singh K, Henry R. Evolution of an intermediate C 4 photosynthesis in the non-foliar tissues of the Poaceae. PHOTOSYNTHESIS RESEARCH 2022; 153:125-134. [PMID: 35648247 DOI: 10.1007/s11120-022-00926-7] [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: 02/08/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Carbon concentrating mechanisms (CCMs) in plants are abaptive features that have evolved to sustain plant growth in unfavorable environments, especially at low atmospheric carbon levels and high temperatures. Uptake of CO2 and its storage in the aerenchyma tissues of Lycopsids and diurnal acidity fluctuation in aquatic plants during the Palaeozoic era (ca. 300 Ma.) would represent the earliest evolution of a CCM. The CCM parts of the dark reactions of photosynthesis have evolved many times, while the light reactions are conserved across plant lineages. A C4 type CCM, leaf C4 photosynthesis is evolved in the PACMAD clade of the Poaceae family. The evolution of C4 photosynthesis from C3 photosynthesis was an abaptation. Photosynthesis in reproductive tissues of sorghum and maize (PACMAD clade) has been shown to be of a weaker C4 type (high CO2 compensation point, low carbon isotope discrimination, and lack of Rubisco compartmentalization, when compared to the normal C4 types) than that in the leaves (normal C4 type). However, this does not fit well with the character polarity concept from an evolutionary perspective. In a recent model proposed for CCM evolution, the development of a rudimentary CCM prior to the evolution of a more efficient CCM (features contrasting to a weaker C4 type, leading to greater biomass production rate) has been suggested. An intermediate crassulacean acid metabolism (CAM) type of CCM (rudimentary) was reported in the genera, Brassia, Coryanthes, Eriopsis, Peristeria, of the orchids (well-known group of plants that display the CAM pathway). Similarly, we propose here the evolution of a rudimentary CCM (C4-like type pathway) in the non-foliar tissues of the Poaceae, prior to the evolution of the C4 pathway as identified in the leaves of the C4 species of the PACMAD clade.
Collapse
Affiliation(s)
- Parimalan Rangan
- ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi, 110012, India.
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia.
| | | | - Rajkumar Subramani
- ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi, 110012, India
| | | | - Surendra K Malik
- ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi, 110012, India
| | | | - Kuldeep Singh
- ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi, 110012, India
| | - Robert Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
| |
Collapse
|
15
|
García-Arriola OA, Roy PD, Vargas-Martínez IG, Giron-García MP, Curtis JH, Israde-Alcantara I, Quiroz-Jimenez JD. Environmental and Hydrological Changes of Lake Coatetelco in Central Mesoamerica (Southwest Mexico) Over the Holocene and Comparison With Climatic Forcing. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.809949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Elemental composition of the inorganic fraction, carbon isotopes, and C/N of organic matter from a new radiocarbon-dated sedimentary sequence collected from Lake Coatetelco (960 m asl) extend information about the environmental and hydrological conditions of central Mesoamerica from the earliest Holocene to the interval of first human settlements in the lake vicinity and nearby streams. Proxy-based reconstructions of erosion/runoff (Ti), water column salinity (CaCO3), sediment–water interactions (PIA), and provenance of organics (δ13Corg and C/N) showed similarities with the summer insolation modulated ITCZ position between ∼11.5 and 4.2 cal ka BP, and more frequent ENSO between ∼4.2 and 2.1 cal ka BP. After a possible depositional hiatus between ∼11.2 and 10.2 cal ka BP, the moderate-to-extremely altered sediments were deposited with enhanced erosion/runoff during the wetter ∼10.2–6 cal ka BP and the organic matter was dominantly autochthonous. Comparison of δ13Corg and C/N suggested that the contribution of C4 plants to organic matter increased over the drier ∼6–4.2 cal ka BP. Sediments representing this middle- Holocene drought-like condition showed geochemical similarity with sediments of the Post-Classic drought (∼1–0.4 cal ka BP), coeval with abandonment of the Xochicalco culture. Variation in seasonal insolation at orbital scales might have forced frequent droughts between ∼6 and 4.2 cal ka BP and the ENSO related short-lived storms possibly led to an unstable hydroclimate after ∼4.2 cal ka BP when the first Olmec settlements commenced in the region. Dissimilarity between this lacustrine archive and speleothems from southwest Mexico for the later part of the Holocene reflected different sensitivities of the geological records to seasonal and-annual precipitation.
Collapse
|
16
|
Winter K, Smith JAC. CAM photosynthesis: the acid test. THE NEW PHYTOLOGIST 2022; 233:599-609. [PMID: 34637529 PMCID: PMC9298356 DOI: 10.1111/nph.17790] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 09/27/2021] [Indexed: 05/04/2023]
Abstract
There is currently considerable interest in the prospects for bioengineering crassulacean acid metabolism (CAM) photosynthesis - or key elements associated with it, such as increased water-use efficiency - into C3 plants. Resolving how CAM photosynthesis evolved from the ancestral C3 pathway could provide valuable insights into the targets for such bioengineering efforts. It has been proposed that the ability to accumulate organic acids at night may be common among C3 plants, and that the transition to CAM might simply require enhancement of pre-existing fluxes, without the need for changes in circadian or diurnal regulation. We show, in a survey encompassing 40 families of vascular plants, that nocturnal acidification is a feature entirely restricted to CAM species. Although many C3 species can synthesize malate during the light period, we argue that the switch to night-time malic acid accumulation requires a fundamental metabolic reprogramming that couples glycolytic breakdown of storage carbohydrate to the process of net dark CO2 fixation. This central element of the CAM pathway, even when expressed at a low level, represents a biochemical capability not seen in C3 plants, and so is better regarded as a discrete evolutionary innovation than as part of a metabolic continuum between C3 and CAM.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research InstitutePO Box 0843‐03092BalboaAncónRepublic of Panama
| | - J. Andrew C. Smith
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| |
Collapse
|
17
|
Abstract
Crassulacean acid metabolism (CAM) has evolved from a C3 ground state to increase water use efficiency of photosynthesis. During CAM evolution, selective pressures altered the abundance and expression patterns of C3 genes and their regulators to enable the trait. The circadian pattern of CO2 fixation and the stomatal opening pattern observed in CAM can be explained largely with a regulatory architecture already present in C3 plants. The metabolic CAM cycle relies on enzymes and transporters that exist in C3 plants and requires tight regulatory control to avoid futile cycles between carboxylation and decarboxylation. Ecological observations and modeling point to mesophyll conductance as a major factor during CAM evolution. The present state of knowledge enables suggestions for genes for a minimal CAM cycle for proof-of-concept engineering, assuming altered regulation of starch synthesis and degradation are not critical elements of CAM photosynthesis and sufficient malic acid export from the vacuole is possible.
Collapse
Affiliation(s)
- Katharina Schiller
- Computational Biology, Faculty of Biology, CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; ,
| | - Andrea Bräutigam
- Computational Biology, Faculty of Biology, CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; ,
| |
Collapse
|
18
|
Winter K, Garcia M, Virgo A, Smith JAC. Low-level CAM photosynthesis in a succulent-leaved member of the Urticaceae, Pilea peperomioides. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:683-690. [PMID: 33287950 DOI: 10.1071/fp20151] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/28/2020] [Indexed: 06/12/2023]
Abstract
Pilea peperomioides Diels (Urticaceae) is a semi-succulent herbaceous species native to south-western China that has become popular in cultivation as an ornamental plant. To investigate whether this species possesses the capacity for CAM photosynthesis, measurements were made of CO2 gas exchange and titratable acidity in plants under both well-watered and water-deficit conditions. Plants were found to assimilate CO2 almost exclusively in the light via C3 photosynthesis. However, distinct transient reductions in the rate of net nocturnal CO2 release were consistently observed during the course of the dark period, and under water-deficit conditions one plant exhibited a brief period of net nocturnal CO2 uptake, providing unequivocal evidence of CAM activity. Furthermore, nocturnal increases in titratable acidity in both leaf laminas and petioles were observed in all plants exposed to wet-dry-wet cycles. This is the first report of CAM in the family Urticaceae. The results are discussed in relation to the phylogenetic position of Pilea and the partially shaded montane habitats in which this species is typically found. An updated list of all plant families currently known to contain species with CAM is presented.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama; and Corresponding author.
| | - Milton Garcia
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Aurelio Virgo
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| |
Collapse
|
19
|
Winter K, Garcia M, Virgo A, Ceballos J, Holtum JAM. Does the C 4 plant Trianthema portulacastrum (Aizoaceae) exhibit weakly expressed crassulacean acid metabolism (CAM)? FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:655-665. [PMID: 33213694 DOI: 10.1071/fp20247] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
We examined whether crassulacean acid metabolism (CAM) is present in Trianthema portulacastrum L. (Aizoaceae), a pantropical, salt-tolerant C4 annual herb with atriplicoid-type Kranz anatomy in leaves but not in stems. The leaves of T. portulacastrum are slightly succulent and the stems are fleshy, similar to some species of Portulaca, the only genus known in which C4 and CAM co-occur. Low- level nocturnal acidification typical of weakly expressed, predominantly constitutive CAM was measured in plants grown for their entire life-cycle in an outdoor raised garden box. Acidification was greater in stems than in leaves. Plants showed net CO2 uptake only during the light irrespective of soil water availability. However, nocturnal traces of CO2 exchange exhibited curved kinetics of reduced CO2 loss during the middle of the night consistent with low-level CAM. Trianthema becomes the second genus of vascular land plants in which C4 and features of CAM have been demonstrated to co-occur in the same plant and the first C4 plant with CAM-type acidification described for the Aizoaceae. Traditionally the stems of herbs are not sampled in screening studies. Small herbs with mildly succulent leaves and fleshy stems might be a numerically significant component of CAM biodiversity.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama; and Corresponding author.
| | - Milton Garcia
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Aurelio Virgo
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Jorge Ceballos
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Joseph A M Holtum
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama; and College of Science and Engineering, James Cook University, Townsville, Qld 4811, Australia
| |
Collapse
|
20
|
Heyduk K, Ray JN, Leebens-Mack J. Leaf anatomy is not correlated to CAM function in a C3+CAM hybrid species, Yucca gloriosa. ANNALS OF BOTANY 2021; 127:437-449. [PMID: 32166326 PMCID: PMC7988526 DOI: 10.1093/aob/mcaa036] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 03/05/2020] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS Crassulacean acid metabolism (CAM) is often considered to be a complex trait, requiring orchestration of leaf anatomy and physiology for optimal performance. However, the observation of trait correlations is based largely on comparisons between C3 and strong CAM species, resulting in a lack of understanding as to how such traits evolve and the level of intraspecific variability for CAM and associated traits. METHODS To understand intraspecific variation for traits underlying CAM and how these traits might assemble over evolutionary time, we conducted detailed time course physiological screens and measured aspects of leaf anatomy in 24 genotypes of a C3+CAM hybrid species, Yucca gloriosa (Asparagaceae). Comparisons were made to Y. gloriosa's progenitor species, Y. filamentosa (C3) and Y. aloifolia (CAM). KEY RESULTS Based on gas exchange and measurement of leaf acids, Y. gloriosa appears to use both C3 and CAM, and varies across genotypes in the degree to which CAM can be upregulated under drought stress. While correlations between leaf anatomy and physiology exist when testing across all three Yucca species, such correlations break down at the species level in Y. gloriosa. CONCLUSIONS The variation in CAM upregulation in Y. gloriosa is a result of its relatively recent hybrid origin. The lack of trait correlations between anatomy and physiology within Y. gloriosa indicate that the evolution of CAM, at least initially, can proceed through a wide combination of anatomical traits, and more favourable combinations are eventually selected for in strong CAM plants.
Collapse
Affiliation(s)
- Karolina Heyduk
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
- For correspondence. E-mail
| | - Jeremy N Ray
- Department of Plant Biology, University of Georgia, Athens, GA, USA
| | - Jim Leebens-Mack
- Department of Plant Biology, University of Georgia, Athens, GA, USA
| |
Collapse
|
21
|
Abstract
With the global climate anomalies and the destruction of ecological balance, the water shortage has become a serious ecological problem facing all mankind, and drought has become a key factor restricting the development of agricultural production. Therefore, it is essential to study the drought tolerance of crops. Based on previous studies, we reviewed the effects of drought stress on plant morphology and physiology, including the changes of external morphology and internal structure of root, stem, and leaf, the effects of drought stress on osmotic regulation substances, drought-induced proteins, and active oxygen metabolism of plants. In this paper, the main drought stress signals and signal transduction pathways in plants are described, and the functional genes and regulatory genes related to drought stress are listed, respectively. We summarize the above aspects to provide valuable background knowledge and theoretical basis for future agriculture, forestry breeding, and cultivation.
Collapse
|
22
|
Henry RJ, Furtado A, Rangan P. Pathways of Photosynthesis in Non-Leaf Tissues. BIOLOGY 2020; 9:E438. [PMID: 33276443 PMCID: PMC7760132 DOI: 10.3390/biology9120438] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/21/2020] [Accepted: 11/22/2020] [Indexed: 01/12/2023]
Abstract
Plants have leaves as specialised organs that capture light energy by photosynthesis. However, photosynthesis is also found in other plant organs. Photosynthesis may be found in the petiole, stems, flowers, fruits, and seeds. All photosynthesis can contribute to the capture of carbon and growth of the plant. The benefit to the plant of photosynthesis in these other tissues or organs may often be associated with the need to re-capture carbon especially in storage organs that have high respiration rates. Some plants that conduct C3 photosynthesis in the leaves have been reported to use C4 photosynthesis in petioles, stems, flowers, fruits, or seeds. These pathways of non-leaf photosynthesis may be especially important in supporting plant growth under stress and may be a key contributor to plant growth and survival. Pathways of photosynthesis have directionally evolved many times in different plant lineages in response to environmental selection and may also have differentiated in specific parts of the plant. This consideration may be useful in the breeding of crop plants with enhanced performance in response to climate change.
Collapse
Affiliation(s)
- Robert J. Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia; (A.F.); (P.R.)
| | - Agnelo Furtado
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia; (A.F.); (P.R.)
| | - Parimalan Rangan
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia; (A.F.); (P.R.)
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, New Delhi 110012, India
| |
Collapse
|
23
|
Yuan G, Hassan MM, Liu D, Lim SD, Yim WC, Cushman JC, Markel K, Shih PM, Lu H, Weston DJ, Chen JG, Tschaplinski TJ, Tuskan GA, Yang X. Biosystems Design to Accelerate C 3-to-CAM Progression. BIODESIGN RESEARCH 2020; 2020:3686791. [PMID: 37849902 PMCID: PMC10521703 DOI: 10.34133/2020/3686791] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/21/2020] [Indexed: 10/19/2023] Open
Abstract
Global demand for food and bioenergy production has increased rapidly, while the area of arable land has been declining for decades due to damage caused by erosion, pollution, sea level rise, urban development, soil salinization, and water scarcity driven by global climate change. In order to overcome this conflict, there is an urgent need to adapt conventional agriculture to water-limited and hotter conditions with plant crop systems that display higher water-use efficiency (WUE). Crassulacean acid metabolism (CAM) species have substantially higher WUE than species performing C3 or C4 photosynthesis. CAM plants are derived from C3 photosynthesis ancestors. However, it is extremely unlikely that the C3 or C4 crop plants would evolve rapidly into CAM photosynthesis without human intervention. Currently, there is growing interest in improving WUE through transferring CAM into C3 crops. However, engineering a major metabolic plant pathway, like CAM, is challenging and requires a comprehensive deep understanding of the enzymatic reactions and regulatory networks in both C3 and CAM photosynthesis, as well as overcoming physiometabolic limitations such as diurnal stomatal regulation. Recent advances in CAM evolutionary genomics research, genome editing, and synthetic biology have increased the likelihood of successful acceleration of C3-to-CAM progression. Here, we first summarize the systems biology-level understanding of the molecular processes in the CAM pathway. Then, we review the principles of CAM engineering in an evolutionary context. Lastly, we discuss the technical approaches to accelerate the C3-to-CAM transition in plants using synthetic biology toolboxes.
Collapse
Affiliation(s)
- Guoliang Yuan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Md. Mahmudul Hassan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Genetics and Plant Breeding, Patuakhali Science and Technology University, Dumki, Patuakhali 8602, Bangladesh
| | - Degao Liu
- Department of Genetics, Cell Biology and Development, Center for Precision Plant Genomics, and Center for Genome Engineering, University of Minnesota, Saint Paul, MN 55108, USA
| | - Sung Don Lim
- Department of Applied Plant Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Won Cheol Yim
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - John C. Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - Kasey Markel
- Department of Plant Biology, University of California, Davis, Davis, CA, USA
| | - Patrick M. Shih
- Department of Plant Biology, University of California, Davis, Davis, CA, USA
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, CA, USA
| | - Haiwei Lu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - David J. Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jin-Gui Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Timothy J. Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Gerald A. Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xiaohan Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
24
|
Herrera A. Are thick leaves, large mesophyll cells and small intercellular air spaces requisites for CAM? ANNALS OF BOTANY 2020; 125:859-868. [PMID: 31970387 PMCID: PMC7218806 DOI: 10.1093/aob/mcaa008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/21/2020] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS It is commonly accepted that the leaf of a crassulacean acid metabolism (CAM) plant is thick, with large mesophyll cells and vacuoles that can accommodate the malic acid produced during the night. The link between mesophyll characteristics and CAM mode, whether obligate or C3/CAM, was evaluated. METHODS Published values of the carbon isotopic ratio (δ 13C) as an indicator of CAM, leaf thickness, leaf micrographs and other evidence of CAM operation were used to correlate cell density, cell area, the proportion of intercellular space in the mesophyll (IAS) and the length of cell wall facing the intercellular air spaces (Lmes/A) with CAM mode. KEY RESULTS Based on 81 species and relatively unrelated families (15) belonging to nine orders, neither leaf thickness nor mesophyll traits helped explain the degree of CAM expression. A strong correlation was found between leaf thickness and δ 13C in some species of Crassulaceae and between leaf thickness and nocturnal acid accumulation in a few obligate CAM species of Bromeliaceae but, when all 81 species were pooled together, no significant changes with δ 13C were observed in cell density, cell area, IAS or Lmes/A. CONCLUSIONS An influence of phylogeny on leaf anatomy was evidenced in a few cases but this precluded generalization for widely separate taxa containing CAM species. The possible relationships between leaf anatomy and CAM mode should be interpreted cautiously.
Collapse
Affiliation(s)
- Ana Herrera
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Caracas, Venezuela
| |
Collapse
|
25
|
Hermida-Carrera C, Fares MA, Font-Carrascosa M, Kapralov MV, Koch MA, Mir A, Molins A, Ribas-Carbó M, Rocha J, Galmés J. Exploring molecular evolution of Rubisco in C 3 and CAM Orchidaceae and Bromeliaceae. BMC Evol Biol 2020; 20:11. [PMID: 31969115 PMCID: PMC6977233 DOI: 10.1186/s12862-019-1551-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 11/29/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The CO2-concentrating mechanism associated to Crassulacean acid metabolism (CAM) alters the catalytic context for Rubisco by increasing CO2 availability and provides an advantage in particular ecological conditions. We hypothesized about the existence of molecular changes linked to these particular adaptations in CAM Rubisco. We investigated molecular evolution of the Rubisco large (L-) subunit in 78 orchids and 144 bromeliads with C3 and CAM photosynthetic pathways. The sequence analyses were complemented with measurements of Rubisco kinetics in some species with contrasting photosynthetic mechanism and differing in the L-subunit sequence. RESULTS We identified potential positively selected sites and residues with signatures of co-adaptation. The implementation of a decision tree model related Rubisco specific variable sites to the leaf carbon isotopic composition of the species. Differences in the Rubisco catalytic traits found among C3 orchids and between strong CAM and C3 bromeliads suggested Rubisco had evolved in response to differing CO2 concentration. CONCLUSIONS The results revealed that the variability in the Rubisco L-subunit sequence in orchids and bromeliads is composed of coevolving sites under potential positive adaptive signal. The sequence variability was related to δ13C in orchids and bromeliads, however it could not be linked to the variability found in the kinetic properties of the studied species.
Collapse
Affiliation(s)
- Carmen Hermida-Carrera
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Ctra. Valldemossa km. 7.5, 07122 Palma, Illes Balears Spain
| | - Mario A. Fares
- Integrative and Systems Biology Group, Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas (CSIC–UPV), 46022 Valencia, Spain
- Department of Genetics, Trinity College Dublin, University of Dublin, Dublin 2, Ireland
| | - Marcel Font-Carrascosa
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Ctra. Valldemossa km. 7.5, 07122 Palma, Illes Balears Spain
| | - Maxim V. Kapralov
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU United Kingdom
| | - Marcus A. Koch
- Department of Biodiversity and Plant Systematics, Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, Im Neuenheimer Feld 345, 9120 Heidelberg, Germany
| | - Arnau Mir
- Computational Biology and Bioinformatics Research Group, Department of Mathematics and Computer Science, Universitat de les Illes Balears, 07122 Palma, Illes Balears Spain
| | - Arántzazu Molins
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Ctra. Valldemossa km. 7.5, 07122 Palma, Illes Balears Spain
| | - Miquel Ribas-Carbó
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Ctra. Valldemossa km. 7.5, 07122 Palma, Illes Balears Spain
| | - Jairo Rocha
- Computational Biology and Bioinformatics Research Group, Department of Mathematics and Computer Science, Universitat de les Illes Balears, 07122 Palma, Illes Balears Spain
| | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Ctra. Valldemossa km. 7.5, 07122 Palma, Illes Balears Spain
| |
Collapse
|
26
|
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
|
27
|
Li MH, Liu DK, Zhang GQ, Deng H, Tu XD, Wang Y, Lan SR, Liu ZJ. A perspective on crassulacean acid metabolism photosynthesis evolution of orchids on different continents: Dendrobium as a case study. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6611-6619. [PMID: 31625570 DOI: 10.1093/jxb/erz461] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 10/05/2019] [Indexed: 05/26/2023]
Abstract
Members of the Orchidaceae, one of the largest families of flowering plants, evolved the crassulacean acid metabolism (CAM) photosynthesis strategy. It is thought that CAM triggers adaptive radiation into new niche spaces, yet very little is known about its origin and diversification on different continents. Here, we assess the prevalence of CAM in Dendrobium, which is one of the largest genera of flowering plants and found in a wide range of environments, from the high altitudes of the Himalayas to relatively arid habitats in Australia. Based on phylogenetic time trees, we estimated that CAM, as determined by δ 13C values less negative than -20.0‰, evolved independently at least eight times in Dendrobium. The oldest lineage appeared in the Asian clade during the middle Miocene, indicating the origin of CAM was associated with a pronounced climatic cooling that followed a period of aridity. Divergence of the four CAM lineages in the Asian clade appeared to be earlier than divergence of those in the Australasian clade. However, CAM species in the Asian clade are much less diverse (25.6%) than those in the Australasian clade (57.9%). These findings shed new light on CAM evolutionary history and the aridity levels of the paleoclimate on different continents.
Collapse
Affiliation(s)
- Ming-He Li
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ding-Kun Liu
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Guo-Qiang Zhang
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, the Orchid Conservation & Research Center of Shenzhen, Shenzhen, China
| | - Hua Deng
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Xiong-De Tu
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yan Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Si-Ren Lan
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhong-Jian Liu
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
| |
Collapse
|
28
|
Edwards EJ. Evolutionary trajectories, accessibility and other metaphors: the case of C 4 and CAM photosynthesis. THE NEW PHYTOLOGIST 2019; 223:1742-1755. [PMID: 30993711 DOI: 10.1111/nph.15851] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/18/2019] [Indexed: 05/24/2023]
Abstract
Are evolutionary outcomes predictable? Adaptations that show repeated evolutionary convergence across the Tree of Life provide a special opportunity to dissect the context surrounding their origins, and identify any commonalities that may predict why certain traits evolved many times in particular clades and yet never evolved in others. The remarkable convergence of C4 and Crassulacean Acid Metabolism (CAM) photosynthesis in vascular plants makes them exceptional model systems for understanding the repeated evolution of complex phenotypes. This review highlights what we have learned about the recurring assembly of C4 and CAM, focusing on the increasingly predictable stepwise evolutionary integration of anatomy and biochemistry. With the caveat that we currently understand C4 evolution better than we do CAM, I propose a general model that explains and unites C4 and CAM evolutionary trajectories. Available data suggest that anatomical modifications are the 'rate-limiting step' in each trajectory, which in large part determines the evolutionary accessibility of both syndromes. The idea that organismal structure exerts a primary influence on innovation is discussed in the context of other systems. Whether the rate-limiting step occurs early or late in the evolutionary assembly of a new phenotype may have profound implications for its distribution across the Tree of Life.
Collapse
Affiliation(s)
- Erika J Edwards
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect St, New Haven, CT, 06520-8105, USA
| |
Collapse
|
29
|
Hancock LP, Holtum JAM, Edwards EJ. The Evolution of CAM Photosynthesis in Australian Calandrinia Reveals Lability in C3+CAM Phenotypes and a Possible Constraint to the Evolution of Strong CAM. Integr Comp Biol 2019; 59:517-534. [DOI: 10.1093/icb/icz089] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Australian Calandrinia has radiated across the Australian continent during the last 30 Ma, and today inhabits most Australian ecosystems. Given its biogeographic range and reports of facultative Crassulacean acid metabolism (CAM) photosynthesis in multiple species, we hypothesized (1) that CAM would be widespread across Australian Calandrinia and that species, especially those that live in arid regions, would engage in strong CAM, and (2) that Australian Calandrinia would be an important lineage for informing on the CAM evolutionary trajectory. We cultivated 22 Australian Calandrinia species for a drought experiment. Using physiological measurements and δ13C values we characterized photosynthetic mode across these species, mapped the resulting character states onto a phylogeny, and characterized the climatic envelopes of species in their native ranges. Most species primarily utilize C3 photosynthesis, with CAM operating secondarily, often upregulated following drought. Several phylogenetically nested species are C3, indicating evolutionary losses of CAM. No strong CAM was detected in any of the species. Results highlight the limitations of δ13C surveys in detecting C3+CAM phenotypes, and the evolutionary lability of C3+CAM phenotypes. We propose a model of CAM evolution that allows for lability and reversibility among C3+CAM phenotypes and C3 and suggest that an annual life-cycle may preclude the evolution of strong CAM.
Collapse
Affiliation(s)
- Lillian P Hancock
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA
- Terrestrial Ecosystems and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville, 4811, Queensland, Australia
| | - Joseph A M Holtum
- Terrestrial Ecosystems and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville, 4811, Queensland, Australia
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT PO Box 208105, 06520, USA
| |
Collapse
|
30
|
Niechayev NA, Pereira PN, Cushman JC. Understanding trait diversity associated with crassulacean acid metabolism (CAM). CURRENT OPINION IN PLANT BIOLOGY 2019; 49:74-85. [PMID: 31284077 DOI: 10.1016/j.pbi.2019.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/30/2019] [Accepted: 06/04/2019] [Indexed: 06/09/2023]
Abstract
Crassulacean acid metabolism (CAM) is a specialized mode of photosynthesis that exploits a temporal CO2 pump with nocturnal CO2 uptake and concentration to reduce photorespiration, improve water-use efficiency (WUE), and optimize the adaptability of plants to climates with seasonal or intermittent water limitations. CAM plants display a plastic continuum in the extent to which species engage in net nocturnal CO2 uptake that ranges from 0 to 100%. CAM plants also display diverse enzyme and organic acid and carbohydrate storage systems, which likely reflect the multiple, independent evolutionary origins of CAM. CAM is often accompanied by a diverse set of anatomical traits, such as tissue succulence and water-storage and water-capture strategies to attenuate drought. Other co-adaptive traits, such as thick cuticles, epicuticular wax, low stomatal density, high stomatal responsiveness, and shallow rectifier-like roots limit water loss under conditions of water deficit. Recommendations for future research efforts to better explore and understand the diversity of traits associated with CAM and CAM Biodesign efforts are presented.
Collapse
Affiliation(s)
- Nicholas A Niechayev
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, NV 89557-0330, United States
| | - Paula N Pereira
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, NV 89557-0330, United States
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, NV 89557-0330, United States.
| |
Collapse
|
31
|
|
32
|
Heyduk K, Hwang M, Albert V, Silvera K, Lan T, Farr K, Chang TH, Chan MT, Winter K, Leebens-Mack J. Altered Gene Regulatory Networks Are Associated With the Transition From C 3 to Crassulacean Acid Metabolism in Erycina (Oncidiinae: Orchidaceae). FRONTIERS IN PLANT SCIENCE 2019; 9:2000. [PMID: 30745906 PMCID: PMC6360190 DOI: 10.3389/fpls.2018.02000] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/24/2018] [Indexed: 05/21/2023]
Abstract
Crassulacean acid metabolism (CAM) photosynthesis is a modification of the core C3 photosynthetic pathway that improves the ability of plants to assimilate carbon in water-limited environments. CAM plants fix CO2 mostly at night, when transpiration rates are low. All of the CAM pathway genes exist in ancestral C3 species, but the timing and magnitude of expression are greatly altered between C3 and CAM species. Understanding these regulatory changes is key to elucidating the mechanism by which CAM evolved from C3. Here, we use two closely related species in the Orchidaceae, Erycina pusilla (CAM) and Erycina crista-galli (C3), to conduct comparative transcriptomic analyses across multiple time points. Clustering of genes with expression variation across the diel cycle revealed some canonical CAM pathway genes similarly expressed in both species, regardless of photosynthetic pathway. However, gene network construction indicated that 149 gene families had significant differences in network connectivity and were further explored for these functional enrichments. Genes involved in light sensing and ABA signaling were some of the most differently connected genes between the C3 and CAM Erycina species, in agreement with the contrasting diel patterns of stomatal conductance in C3 and CAM plants. Our results suggest changes to transcriptional cascades are important for the transition from C3 to CAM photosynthesis in Erycina.
Collapse
Affiliation(s)
- Karolina Heyduk
- Department of Plant Biology, University of Georgia, Athens, GA, United States
| | - Michelle Hwang
- Department of Plant Biology, University of Georgia, Athens, GA, United States
| | - Victor Albert
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Katia Silvera
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Tianying Lan
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
| | - Kimberly Farr
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
| | - Tien-Hao Chang
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, United States
| | - Ming-Tsair Chan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Jim Leebens-Mack
- Department of Plant Biology, University of Georgia, Athens, GA, United States
| |
Collapse
|
33
|
Zhang S, Yang Y, Li J, Qin J, Zhang W, Huang W, Hu H. Physiological diversity of orchids. PLANT DIVERSITY 2018; 40:196-208. [PMID: 30740565 PMCID: PMC6137271 DOI: 10.1016/j.pld.2018.06.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/09/2018] [Accepted: 06/20/2018] [Indexed: 05/04/2023]
Abstract
The Orchidaceae is a diverse and wide spread family of flowering plants that are of great value in ornamental, medical, conservation, and evolutionary research. The broad diversity in morphology, growth form, life history, and habitat mean that the members of Orchidaceae exhibit various physiological properties. Epiphytic orchids are often characterized by succulent leaves with thick cell walls, cuticles, and sunken stomata, whereas terrestrial orchids possess rhizomes, corms, or tubers. Most orchids have a long juvenile period, slow growth rate, and low photosynthetic capacity. This reduced photosynthetic potential can be largely explained by CO2 diffusional conductance and leaf internal structure. The amount of light required for plant survival depends upon nutritional mode, growth form, and habitat. Most orchids can adapt to their light environments through morphological and physiological adjustments but are sensitive to sudden changes in irradiance. Orchids that originate from warm regions are susceptible to chilling temperatures, whereas alpine members are vulnerable to high temperatures. For epiphytic orchids, rapid water uptake by the velamen radicum, water storage in their pseudobulbs and leaves, slow water loss, and Crassulacean Acid Metabolism contribute to plant-water balance and tolerance to drought stress. The presence of the velamen radicum and mycorrhizal fungi may compensate for the lack of root hairs, helping with quick absorbance of nutrients from the atmosphere. Under cultivation conditions, the form and concentration of nitrogen affect orchid growth and flowering. However, the limitations of nitrogen and phosphorous on epiphytic orchids in the wild, which require these plants to depend on mycorrhizal fungi for nutrients throughout the entire life cycle, are not clearly understood. Because they lack endosperm, seed germination depends upon obtaining nutrients via mycorrhizal fungi. Adult plants of some autotrophic orchids also gain carbon, nitrogen, phosphorus, and other elements from their mycorrhizal partners. Future studies should examine the mechanisms that determine slow growth and flower induction, the physiological causes of variations in flowering behavior and floral lifespan, the effects of nutrients and atmospheric-nitrogen deposition, and practical applications of mycorrhizal fungi in orchid cultivation.
Collapse
Affiliation(s)
- Shibao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Yingjie Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiawei Li
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiao Qin
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Wei Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Wei Huang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Hong Hu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| |
Collapse
|
34
|
Males J. Concerted anatomical change associated with crassulacean acid metabolism in the Bromeliaceae. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:681-695. [PMID: 32291044 DOI: 10.1071/fp17071] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 01/05/2018] [Indexed: 06/11/2023]
Abstract
Crassulacean acid metabolism (CAM) is a celebrated example of convergent evolution in plant ecophysiology. However, many unanswered questions surround the relationships among CAM, anatomy and morphology during evolutionary transitions in photosynthetic pathway. An excellent group in which to explore these issues is the Bromeliaceae, a diverse monocot family from the Neotropics in which CAM has evolved multiple times. Progress in the resolution of phylogenetic relationships among the bromeliads is opening new and exciting opportunities to investigate how evolutionary changes in leaf structure has tracked, or perhaps preceded, photosynthetic innovation. This paper presents an analysis of variation in leaf anatomical parameters across 163C3 and CAM bromeliad species, demonstrating a clear divergence in the fundamental aspects of leaf structure in association with the photosynthetic pathway. Most strikingly, the mean volume of chlorenchyma cells of CAM species is 22 times higher than that of C3 species. In two bromeliad subfamilies (Pitcairnioideae and Tillandsioideae), independent transitions from C3 to CAM are associated with increased cell succulence, whereas evolutionary trends in tissue thickness and leaf air space content differ between CAM origins. Overall, leaf anatomy is clearly and strongly coupled with the photosynthetic pathway in the Bromeliaceae, where the independent origins of CAM have involved significant anatomical restructuring.
Collapse
Affiliation(s)
- Jamie Males
- Department of Plant Sciences, University of Cambridge, Cambridge, UK. Email
| |
Collapse
|
35
|
Heyduk K, Ray JN, Ayyampalayam S, Leebens-Mack J. Shifts in gene expression profiles are associated with weak and strong Crassulacean acid metabolism. AMERICAN JOURNAL OF BOTANY 2018; 105:587-601. [PMID: 29746718 DOI: 10.1002/ajb2.1017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/19/2017] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY The relative ease of high throughput sequencing is facilitating comprehensive phylogenomic and gene expression studies, even for nonmodel groups. To date, however, these two approaches have not been merged; while phylogenomic methods might use transcriptome sequences to resolve relationships, assessment of gene expression patterns in a phylogenetic context is less common. Here we analyzed both carbon assimilation and gene expression patterns of closely related species within the Agavoideae (Asparagaceae) to elucidate changes in gene expression across weak and strong phenotypes for Crassulacean acid metabolism (CAM). METHODS Gene expression patterns were compared across four genera: Agave (CAM), which is paraphyletic with Polianthes (weak CAM) and Manfreda (CAM), and Beschorneria (weak CAM). RNA-sequencing was paired with measures of gas exchange and titratable acidity. Climate niche space was compared across the four lineages to examine abiotic factors and their correlation to CAM. KEY RESULTS Expression of homologous genes showed both shared and variable patterns in weak and strong CAM species. Network analysis highlights that despite shared expression patterns, highly connected genes differ between weak and strong CAM, implicating shifts in regulatory gene function as key for the evolution of CAM. Variation in carbohydrate metabolism between weak and strong CAM supports the importance of sugar turnovers for CAM physiology. CONCLUSIONS Integration of phylogenetics and RNA-sequencing provides a powerful tool to study the evolution of CAM photosynthesis across closely related but photosynthetically variable species. Our findings regarding shared or shifted gene expression and regulation of CAM via carbohydrate metabolism have important implications for efforts to engineer the CAM pathway into C3 food and biofuel crops.
Collapse
Affiliation(s)
- Karolina Heyduk
- Miller Plant Sciences, University of Georgia, 120 Carlton Street, 2502, Athens, Georgia, 30602, USA
| | - Jeremy N Ray
- Miller Plant Sciences, University of Georgia, 120 Carlton Street, 2502, Athens, Georgia, 30602, USA
| | | | - James Leebens-Mack
- Miller Plant Sciences, University of Georgia, 120 Carlton Street, 2502, Athens, Georgia, 30602, USA
| |
Collapse
|
36
|
Functional Anatomical Traits of the Photosynthetic Organs of Plants with Crassulacean Acid Metabolism. THE LEAF: A PLATFORM FOR PERFORMING PHOTOSYNTHESIS 2018. [DOI: 10.1007/978-3-319-93594-2_10] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
37
|
Holtum JAM, Hancock LP, Edwards EJ, Winter K. Facultative CAM photosynthesis (crassulacean acid metabolism) in four species of Calandrinia, ephemeral succulents of arid Australia. PHOTOSYNTHESIS RESEARCH 2017; 134:17-25. [PMID: 28871459 DOI: 10.1007/s11120-017-0359-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/14/2017] [Indexed: 06/07/2023]
Abstract
Crassulacean acid metabolism (CAM) was demonstrated in four small endemic Australian terrestrial succulents from the genus Calandrinia (Montiaceae) viz. C. creethiae, C. pentavalvis, C. quadrivalvis and C. reticulata. CAM was substantiated by measurements of CO2 gas-exchange and nocturnal acidification. In all species, the expression of CAM was overwhelmingly facultative in that nocturnal H+ accumulation was greatest in droughted plants and zero, or close to zero, in plants that were well-watered, including plants that had been droughted and were subsequently rewatered, i.e. the inducible component was proven to be reversible. Gas-exchange measurements complemented the determinations of acidity. In all species, net CO2 uptake was restricted to the light in well-watered plants, and cessation of watering was followed by a progressive reduction of CO2 uptake in the light and a reduction in nocturnal CO2 efflux. In C. creethiae, C. pentavalvis and C. reticulata net CO2 assimilation was eventually observed in the dark, whereas in C. quadrivalvis nocturnal CO2 exchange approached the compensation point but did not transition to net CO2 gain. Following rewatering, all species returned to their original well-watered CO2 exchange pattern of net CO2 uptake restricted solely to the light. In addition to facultative CAM, C. quadrivalvis and C. reticulata exhibited an extremely small constitutive CAM component as demonstrated by the nocturnal accumulation in well-watered plants of small amounts of acidity and by the curved pattern of the nocturnal course of CO2 efflux. It is suggested that low-level CAM and facultative CAM are more common within the Australian succulent flora, and perhaps the world succulent flora, than has been previously assumed.
Collapse
Affiliation(s)
- Joseph A M Holtum
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama.
| | - Lillian P Hancock
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI, 02912, USA
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI, 02912, USA
| | - Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| |
Collapse
|
38
|
Evolution of a CAM anatomy predates the origins of Crassulacean acid metabolism in the Agavoideae (Asparagaceae). Mol Phylogenet Evol 2016; 105:102-113. [DOI: 10.1016/j.ympev.2016.08.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 11/20/2022]
|
39
|
Heyduk K, Burrell N, Lalani F, Leebens-Mack J. Gas exchange and leaf anatomy of a C3-CAM hybrid, Yucca gloriosa (Asparagaceae). JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1369-79. [PMID: 26717954 PMCID: PMC4762382 DOI: 10.1093/jxb/erv536] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
While the majority of plants use the typical C3 carbon metabolic pathway, ~6% of angiosperms have adapted to carbon limitation as a result of water stress by employing a modified form of photosynthesis known as Crassulacean acid metabolism (CAM). CAM plants concentrate carbon in the cells by temporally separating atmospheric carbon acquisition from fixation into carbohydrates. CAM has been studied for decades, but the evolutionary progression from C3 to CAM remains obscure. In order to better understand the morphological and physiological characteristics associated with CAM photosynthesis, phenotypic variation was assessed in Yucca aloifolia, a CAM species, Yucca filamentosa, a C3 species, and Yucca gloriosa, a hybrid species derived from these two yuccas exhibiting intermediate C3-CAM characteristics. Gas exchange, titratable leaf acidity, and leaf anatomical traits of all three species were assayed in a common garden under well-watered and drought-stressed conditions. Yucca gloriosa showed intermediate phenotypes for nearly all traits measured, including the ability to acquire carbon at night. Using the variation found among individuals of all three species, correlations between traits were assessed to better understand how leaf anatomy and CAM physiology are related. Yucca gloriosa may be constrained by a number of traits which prevent it from using CAM to as high a degree as Y. aloifolia. The intermediate nature of Y. gloriosa makes it a promising system in which to study the evolution of CAM.
Collapse
Affiliation(s)
- Karolina Heyduk
- 2502 Miller Plant Sciences, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Nia Burrell
- 2502 Miller Plant Sciences, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Falak Lalani
- 2502 Miller Plant Sciences, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Jim Leebens-Mack
- 2502 Miller Plant Sciences, Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
40
|
Habibi G, Ajory N. The effect of drought on photosynthetic plasticity in Marrubium vulgare plants growing at low and high altitudes. JOURNAL OF PLANT RESEARCH 2015; 128:987-994. [PMID: 26314352 DOI: 10.1007/s10265-015-0748-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/04/2015] [Indexed: 06/04/2023]
Abstract
Photosynthesis is a biological process most affected by water deficit. Plants have various photosynthetic mechanisms that are matched to specific climatic zones. We studied the photosynthetic plasticity of C3 plants at water deficit using ecotypes of Marrubium vulgare L. from high (2,200 m) and low (1,100 m) elevation sites in the Mishou-Dagh Mountains of Iran. Under experimental drought, high-altitude plants showed more tolerance to water stress based on most of the parameters studied as compared to the low-altitude plants. Increased tolerance in high-altitude plants was achieved by lower levels of daytime stomatal conductance (g s) and reduced damaging effect on maximal quantum yield of photosystem II (PSII) (F v /F m ) coupled with higher levels of carotenoids and non-photochemical quenching (NPQ). High-altitude plants exhibited higher water use efficiency (WUE) than that in low-altitude plants depending on the presence of thick leaves and the reduced daytime stomatal conductance. Additionally, we have studied the oscillation in H(+) content and diel gas exchange patterns to determine the occurrence of C3 or weak CAM (Crassulacean acid metabolism) in M. vulgare through 15 days drought stress. Under water-stressed conditions, low-altitude plants exhibited stomatal conductance and acid fluctuations characteristic of C3 photosynthesis, though high-altitude plants exhibited more pronounced increases in nocturnal acidity and phosphoenolpyruvate carboxylase (PEPC) activity, suggesting photosynthetic flexibility. These results indicated that the regulation of carotenoids, NPQ, stomatal conductance and diel patterns of CO2 exchange presented the larger differences among studied plants at different altitudes and seem to be the protecting mechanisms controlling the photosynthetic performance of M. vulgare plants under drought conditions.
Collapse
Affiliation(s)
- Ghader Habibi
- Department of Biology, Payame Noor University, PO BOX 19395-3697, Tehran, Iran.
| | - Neda Ajory
- Department of Biology, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
| |
Collapse
|
41
|
Bone RE, Smith JAC, Arrigo N, Buerki S. A macro-ecological perspective on crassulacean acid metabolism (CAM) photosynthesis evolution in Afro-Madagascan drylands: Eulophiinae orchids as a case study. THE NEW PHYTOLOGIST 2015; 208:469-81. [PMID: 26192467 DOI: 10.1111/nph.13572] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 06/18/2015] [Indexed: 05/13/2023]
Abstract
Crassulacean acid metabolism (CAM) photosynthesis is an adaptation to water and atmospheric CO2 deficits that has been linked to diversification in dry-adapted plants. We investigated whether CAM evolution can be associated with the availability of new or alternative niches, using Eulophiinae orchids as a case study. Carbon isotope ratios, geographical and climate data, fossil records and DNA sequences were used to: assess the prevalence of CAM in Eulophiinae orchids; characterize the ecological niche of extant taxa; infer divergence times; and estimate whether CAM is associated with niche shifts. CAM evolved in four terrestrial lineages during the late Miocene/Pliocene, which have uneven diversification patterns. These lineages originated in humid habitats and colonized dry/seasonally dry environments in Africa and Madagascar. Additional key features (variegation, heterophylly) evolved in the most species-rich CAM lineages. Dry habitats were also colonized by a lineage that includes putative mycoheterotrophic taxa. These findings indicate that the switch to CAM is associated with environmental change. With its suite of adaptive traits, this group of orchids represents a unique opportunity to study the adaptations to dry environments, especially in the face of projected global aridification.
Collapse
Affiliation(s)
- Ruth E Bone
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Nils Arrigo
- Department of Ecology and Evolution, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Sven Buerki
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| |
Collapse
|
42
|
Winter K, Holtum JAM, Smith JAC. Crassulacean acid metabolism: a continuous or discrete trait? THE NEW PHYTOLOGIST 2015; 208:73-8. [PMID: 25975197 DOI: 10.1111/nph.13446] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/22/2015] [Indexed: 05/27/2023]
Abstract
The key components of crassulacean acid metabolism (CAM) - nocturnal fixation of atmospheric CO2 and its processing via Rubisco in the subsequent light period - are now reasonably well understood in terms of the biochemical reactions defining this water-saving mode of carbon assimilation. Phenotypically, however, the degree to which plants engage in the CAM cycle relative to regular C3 photosynthesis is highly variable. Depending upon species, ontogeny and environment, the contribution of nocturnal CO2 fixation to 24-h carbon gain can range continuously from close to 0% to 100%. Nevertheless, not all possible combinations of light and dark CO2 fixation appear equally common. Large-scale surveys of carbon-isotope ratios typically show a strongly bimodal frequency distribution, with relatively few intermediate values. Recent research has revealed that many species capable of low-level CAM activity are nested within the peak of C3 -type isotope signatures. While questions remain concerning the adaptive significance of dark CO2 fixation in such species, plants with low-level CAM should prove valuable models for investigating the discrete changes in genetic architecture and gene expression that have enabled the evolutionary transition from C3 to CAM.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Joseph A M Holtum
- Centre for Tropical Biodiversity and Climate Change, James Cook University, Townsville, QLD, 4811, Australia
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| |
Collapse
|
43
|
Deng H, Zhang GQ, Lin M, Wang Y, Liu ZJ. Mining from transcriptomes: 315 single-copy orthologous genes concatenated for the phylogenetic analyses of Orchidaceae. Ecol Evol 2015; 5:3800-7. [PMID: 26380706 PMCID: PMC4567881 DOI: 10.1002/ece3.1642] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 07/06/2015] [Accepted: 07/08/2015] [Indexed: 01/31/2023] Open
Abstract
Phylogenetic relationships are hotspots for orchid studies with controversial standpoints. Traditionally, the phylogenies of orchids are based on morphology and subjective factors. Although more reliable than classic phylogenic analyses, the current methods are based on a few gene markers and PCR amplification, which are labor intensive and cannot identify the placement of some species with degenerated plastid genomes. Therefore, a more efficient, labor-saving and reliable method is needed for phylogenic analysis. Here, we present a method of orchid phylogeny construction using transcriptomes. Ten representative species covering five subfamilies of Orchidaceae were selected, and 315 single-copy orthologous genes extracted from the transcriptomes of these organisms were applied to reconstruct a more robust phylogeny of orchids. This approach provided a rapid and reliable method of phylogeny construction for Orchidaceae, one of the most diversified family of angiosperms. We also showed the rigorous systematic position of holomycotrophic species, which has previously been difficult to determine because of the degenerated plastid genome. We concluded that the method presented in this study is more efficient and reliable than methods based on a few gene markers for phylogenic analyses, especially for the holomycotrophic species or those whose DNA sequences have been difficult to amplify. Meanwhile, a total of 315 single-copy orthologous genes of orchids are offered and more informative loci could be used in the future orchid phylogenetic studies.
Collapse
Affiliation(s)
- Hua Deng
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, 100091, China
| | - Guo-Qiang Zhang
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of ShenzhenShenzhen 518114, China
| | - Min Lin
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of ShenzhenShenzhen 518114, China
| | - Yan Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of ForestryBeijing, 100091, China
| | - Zhong-Jian Liu
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of ShenzhenShenzhen 518114, China
- The Center for Biotechnology and BioMedicine, Graduate School at Shenzhen, Tsinghua UniversityShenzhen 518055, China
- College of Forestry, South China Agricultural UniversityGuangzhou 510642, China
| |
Collapse
|
44
|
Winter K, Holtum JAM. Cryptic crassulacean acid metabolism (CAM) in Jatropha curcas. FUNCTIONAL PLANT BIOLOGY : FPB 2015; 42:711-717. [PMID: 32480714 DOI: 10.1071/fp15021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/13/2015] [Indexed: 06/11/2023]
Abstract
Jatropha curcas L. is a drought-tolerant shrub or small tree that is a candidate bioenergy feedstock. It is a member of the family Euphorbiaceae in which both CAM and C4 photosynthesis have evolved. Here, we report that J. curcas exhibits features diagnostic of low-level CAM. Small increases in nocturnal acid content were consistently observed in photosynthetic stems and occasionally in leaves. Acidification was associated with transient contractions in CO2 loss at night rather than with net CO2 dark fixation. Although the CAM-type nocturnal CO2 uptake signal was masked by background respiration, estimates of dark CO2 fixation based upon the 2:1 stoichiometric relationship between H+ accumulated and CO2 fixed indicated substantial carbon retention in the stems via the CAM cycle. It is proposed that under conditions of drought, low-level CAM in J. curcas stems serves primarily to conserve carbon rather than water.
Collapse
Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| | - Joseph A M Holtum
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Republic of Panama
| |
Collapse
|
45
|
Herrera A, Ballestrini C, Montes E. What is the potential for dark CO2 fixation in the facultative crassulacean acid metabolism species Talinum triangulare? JOURNAL OF PLANT PHYSIOLOGY 2015; 174:55-61. [PMID: 25462967 DOI: 10.1016/j.jplph.2014.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/15/2014] [Accepted: 10/15/2014] [Indexed: 06/04/2023]
Abstract
In obligate Crassulacean acid metabolism (CAM) plants, dark CO2 fixation is almost the sole route of CO2 fixation and, under drought, continues for long periods. In contrast, in plants of the facultative CAM species Talinum triangulare under experimental drought, dark CO2 fixation provides a small proportion of the daily assimilation observed in watered plants and occurs only for a few days, after which almost nil CO2 fixation is observed. Under field conditions, with a practically unlimited substrate volume, drought-induced CAM might operate for a longer period and make a higher contribution to daily CO2 fixation. Greenhouse-grown plants of T. triangulare were subjected to low and nearly constant soil water content; the operation of CAM was assessed through the measurement of nocturnal proton accumulation and dark CO2 fixation. Dark CO2 fixation appeared 19d after the onset of drought; its contribution during three months of experiment to daily CO2 assimilation ranged from 0.5 to 30.7% with a mean of 13.5%. Twenty days after the beginning of treatment, nocturnal proton accumulation increased six times and remained high for over three months. In spite of low soil water content, leaves did not engage in dark CO2 fixation all the time but dark CO2 fixation was large enough to produce an increase in relative (13)C composition of mature leaves compared to watered plants but not to the value in short-term drought experiments. Leaf anatomical characteristics may guarantee the achievement of higher rates of dark CO2 fixation but results evidence the occurrence of a limit to the expression of CAM that remains to be determined.
Collapse
Affiliation(s)
- Ana Herrera
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Caracas 1041, Venezuela.
| | - Caín Ballestrini
- Centro de Botánica Tropical, Instituto de Biología Experimental, Universidad Central de Venezuela, Caracas 1041, Venezuela
| | - Enrique Montes
- College of Marine Sciences, University of South Florida, St. Petersburg, FA 33701-5016, USA
| |
Collapse
|
46
|
Horn JW, Xi Z, Riina R, Peirson JA, Yang Y, Dorsey BL, Berry PE, Davis CC, Wurdack KJ. Evolutionary bursts inEuphorbia(Euphorbiaceae) are linked with photosynthetic pathway. Evolution 2014; 68:3485-504. [DOI: 10.1111/evo.12534] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 09/17/2014] [Indexed: 12/29/2022]
Affiliation(s)
- James W. Horn
- Department of Botany; Smithsonian Institution; NMNH MRC-166, P.O. Box 37012 Washington DC 20013
| | - Zhenxiang Xi
- Department of Organismic and Evolutionary Biology; Harvard University Herbaria; 22 Divinity Avenue Cambridge Massachusetts 02138
| | - Ricarda Riina
- Department of Ecology and Evolutionary Biology and University of Michigan Herbarium; 3600 Varsity Drive Ann Arbor Michigan 48108
- Real Jardín Botánico; RJB-CSIC; Plaza de Murillo 2 28014 Madrid Spain
| | - Jess A. Peirson
- Department of Ecology and Evolutionary Biology and University of Michigan Herbarium; 3600 Varsity Drive Ann Arbor Michigan 48108
| | - Ya Yang
- Department of Ecology and Evolutionary Biology and University of Michigan Herbarium; 3600 Varsity Drive Ann Arbor Michigan 48108
| | - Brian L. Dorsey
- Department of Ecology and Evolutionary Biology and University of Michigan Herbarium; 3600 Varsity Drive Ann Arbor Michigan 48108
- The Huntington Botanical Gardens; 1151 Oxford Road San Marino California 91108
| | - Paul E. Berry
- Department of Ecology and Evolutionary Biology and University of Michigan Herbarium; 3600 Varsity Drive Ann Arbor Michigan 48108
| | - Charles C. Davis
- Department of Organismic and Evolutionary Biology; Harvard University Herbaria; 22 Divinity Avenue Cambridge Massachusetts 02138
| | - Kenneth J. Wurdack
- Department of Botany; Smithsonian Institution; NMNH MRC-166, P.O. Box 37012 Washington DC 20013
| |
Collapse
|
47
|
Holtum JAM, Winter K. Limited photosynthetic plasticity in the leaf-succulent CAM plant Agave angustifolia grown at different temperatures. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:843-849. [PMID: 32481038 DOI: 10.1071/fp13284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 02/19/2014] [Indexed: 06/11/2023]
Abstract
In Agave angustifolia Haw., a leaf-succulent constitutive crassulacean acid metabolism (CAM) plant of tropical Panama, we tested whether nocturnal CO2 uptake and growth were reduced at night temperatures above 20°C. Unlike some CAM model species from habitats with pronounced day-night temperature variations, in A. angustifolia temperature affected little the relative contributions of CAM and C3 photosynthesis to growth. In plants grown under 12h light/dark regimes of 25/17, 30/22 and 35/27°C, biomass increased with temperature. Maintaining day temperature at 35°C and reducing night temperature from 27 to 17°C markedly lowered growth, a reduction partially reversed when roots were heated to 27°C. Across all treatments, whole-shoot δ13C values ranged between -14.6 and -13.2 ‰, indicating a stable proportion of CO2 was fixed at night, between 75 and 83%. Nocturnal acidification reflected growth, varying between 339 and 393μmol H+ g-1 fresh mass and 63-87μmol H+ cm-2. In outdoor open-top chambers, warming the air 3°C above ambient at night did not reduce biomass accumulation. The persistence of a high capacity for nocturnal CO2 fixation at the expense of a limited capacity for switching between C3 and CAM probably makes this Agave, and others like it, potential species for biomass production in seasonally-dry landscapes.
Collapse
Affiliation(s)
- Joseph A M Holtum
- Tropical Biology, James Cook University, Townsville, Qld 4811, Australia
| | - Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| |
Collapse
|
48
|
Barrera Zambrano VA, Lawson T, Olmos E, Fernández-García N, Borland AM. Leaf anatomical traits which accommodate the facultative engagement of crassulacean acid metabolism in tropical trees of the genus Clusia. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3513-3523. [PMID: 24510939 DOI: 10.1093/jxb/eru022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Succulence and leaf thickness are important anatomical traits in CAM plants, resulting from the presence of large vacuoles to store organic acids accumulated overnight. A higher degree of succulence can result in a reduction in intercellular air space which constrains internal conductance to CO2. Thus, succulence presents a trade-off between the optimal anatomy for CAM and the internal structure ideal for direct C3 photosynthesis. This study examined how plasticity for the reversible engagement of CAM in the genus Clusia could be accommodated by leaf anatomical traits that could facilitate high nocturnal PEPC activity without compromising the direct day-time uptake of CO2 via Rubisco. Nine species of Clusia ranging from constitutive C3 through C3/CAM intermediates to constitutive CAM were compared in terms of leaf gas exchange, succulence, specific leaf area, and a range of leaf anatomical traits (% intercellular air space (IAS), length of mesophyll surface exposed to IAS per unit area, cell size, stomatal density/size). Relative abundances of PEPC and Rubisco proteins in different leaf tissues of a C3 and a CAM-performing species of Clusia were determined using immunogold labelling. The results indicate that the relatively well-aerated spongy mesophyll of Clusia helps to optimize direct C3-mediated CO2 fixation, whilst enlarged palisade cells accommodate the potential for C4 carboxylation and nocturnal storage of organic acids. The findings provide insight on the optimal leaf anatomy that could accommodate the bioengineering of inducible CAM into C3 crops as a means of improving water use efficiency without incurring detrimental consequences for direct C3-mediated photosynthesis.
Collapse
Affiliation(s)
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - Enrique Olmos
- CEBAS-CSIC Campus Universitario de Espinardo, Department of Abiotic Stress and Plant Pathology, 30100 Murcia, Spain
| | - Nieves Fernández-García
- CEBAS-CSIC Campus Universitario de Espinardo, Department of Abiotic Stress and Plant Pathology, 30100 Murcia, Spain
| | - Anne M Borland
- School of Biology, Newcastle University, Newcastle upon Tyne NE17RU, UK Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6407, USA
| |
Collapse
|
49
|
Silvera K, Winter K, Rodriguez BL, Albion RL, Cushman JC. Multiple isoforms of phosphoenolpyruvate carboxylase in the Orchidaceae (subtribe Oncidiinae): implications for the evolution of crassulacean acid metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3623-36. [PMID: 24913627 PMCID: PMC4085970 DOI: 10.1093/jxb/eru234] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Phosphoenolpyruvate carboxylase (PEPC) catalyses the initial fixation of atmospheric CO2 into oxaloacetate and subsequently malate. Nocturnal accumulation of malic acid within the vacuole of photosynthetic cells is a typical feature of plants that perform crassulacean acid metabolism (CAM). PEPC is a ubiquitous plant enzyme encoded by a small gene family, and each member encodes an isoform with specialized function. CAM-specific PEPC isoforms probably evolved from ancestral non-photosynthetic isoforms by gene duplication events and subsequent acquisition of transcriptional control elements that mediate increased leaf-specific or photosynthetic-tissue-specific mRNA expression. To understand the patterns of functional diversification related to the expression of CAM, ppc gene families and photosynthetic patterns were characterized in 11 closely related orchid species from the subtribe Oncidiinae with a range of photosynthetic pathways from C3 photosynthesis (Oncidium cheirophorum, Oncidium maduroi, Rossioglossum krameri, and Oncidium sotoanum) to weak CAM (Oncidium panamense, Oncidium sphacelatum, Gomesa flexuosa and Rossioglossum insleayi) and strong CAM (Rossioglossum ampliatum, Trichocentrum nanum, and Trichocentrum carthagenense). Phylogenetic analysis revealed the existence of two main ppc lineages in flowering plants, two main ppc lineages within the eudicots, and three ppc lineages within the Orchidaceae. Our results indicate that ppc gene family expansion within the Orchidaceae is likely to be the result of gene duplication events followed by adaptive sequence divergence. CAM-associated PEPC isoforms in the Orchidaceae probably evolved from several independent origins.
Collapse
Affiliation(s)
- Katia Silvera
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama Department of Biochemistry & Molecular Biology, MS330, University of Nevada, Reno, NV 89557-0330, USA
| | - Klaus Winter
- Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancon, Republic of Panama
| | - B Leticia Rodriguez
- Department of Biochemistry & Molecular Biology, MS330, University of Nevada, Reno, NV 89557-0330, USA
| | - Rebecca L Albion
- Department of Biochemistry & Molecular Biology, MS330, University of Nevada, Reno, NV 89557-0330, USA
| | - John C Cushman
- Department of Biochemistry & Molecular Biology, MS330, University of Nevada, Reno, NV 89557-0330, USA
| |
Collapse
|
50
|
Quezada IM, Zotz G, Gianoli E. Latitudinal variation in the degree of crassulacean acid metabolism in Puya chilensis. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16:848-852. [PMID: 24739103 DOI: 10.1111/plb.12181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Crassulacean acid metabolism (CAM) is a photosynthetic pathway found in many plant species from arid and semiarid environments. Few studies aiming to characterise plant species as CAM or C3 account for inter-population differences in photosynthetic pathway, often relying on samples taken from herbarium material and/or a single plant or population. This may be especially problematic for species growing under contrasting climate conditions, as is the case for species with a wide geographic range. We used Puya chilensis, a species previously reported as CAM and C3, to study among-population variation in expression of the CAM pathway within its distribution range, which spans a significant climate gradient. We carried out a wide sampling scheme, including five populations and a combination of analytical methods (quantification of nocturnal acidification and stable isotope measurements). The study populations of P. chilensis encompass the entire latitudinal distribution range, from semi-arid to temperate oceanic climates. Our results indicate that CAM decreased with latitude. However, even in the southern (wetter) populations, where δ13C values were indicative of C3 metabolism, we found some nocturnal acidification. We stress the value of using two methods along with the use of samples from different populations, as this allows more reliable conclusions on the photosynthetic pathway for 'probable' CAM species that face varying climate conditions within their distribution ranges.
Collapse
Affiliation(s)
- I M Quezada
- Departamento de Botánica, Universidad de Concepción, Concepción, Chile
| | | | | |
Collapse
|