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Coiro M, McLoughlin S, Steinthorsdottir M, Vajda V, Fabrikant D, Seyfullah LJ. Parallel evolution of angiosperm-like venation in Peltaspermales: a reinvestigation of Furcula. THE NEW PHYTOLOGIST 2024; 242:2845-2856. [PMID: 38623034 DOI: 10.1111/nph.19726] [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: 09/05/2023] [Accepted: 03/15/2024] [Indexed: 04/17/2024]
Abstract
Leaf venation is a pivotal trait in the success of vascular plants. Whereas gymnosperms have single or sparsely branched parallel veins, angiosperms developed a hierarchical structure of veins that form a complex reticulum. Its physiological consequences are considered to have enabled angiosperms to dominate terrestrial ecosystems in the Late Cretaceous and Cenozoic. Although a hierarchical-reticulate venation also occurs in some groups of extinct seed plants, it is unclear whether these are stem relatives of angiosperms or have evolved these traits in parallel. Here, we re-examine the morphology of the enigmatic foliage taxon Furcula, a potential early Mesozoic angiosperm relative, and argue that its hierarchical vein network represents convergent evolution (in the Late Triassic) with flowering plants (which developed in the Early Cretaceous) based on details of vein architecture and the absence of angiosperm-like stomata and guard cells. We suggest that its nearest relatives are Peltaspermales similar to Scytophyllum and Vittaephyllum, the latter being a genus that originated during the Late Triassic (Carnian) and shares a hierarchical vein system with Furcula. We further suggest that the evolution of hierarchical venation systems in the early Permian, the Late Triassic, and the Early Cretaceous represent 'natural experiments' that might help resolve the selective pressures enabling this trait to evolve.
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Affiliation(s)
- Mario Coiro
- Department of Palaeontology, University of Vienna, 1090, Vienna, Austria
- Ronin Institute for Independent Scholarship, Montclair, NJ, 07043, USA
| | - Stephen McLoughlin
- Department of Palaeobiology, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
| | - Margret Steinthorsdottir
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, 114 19, Stockholm, Sweden
| | - Vivi Vajda
- Department of Palaeobiology, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
| | - Dolev Fabrikant
- The Hebrew University of Jerusalem, Jerusalem, 9190501, Israel
| | - Leyla J Seyfullah
- Department of Palaeontology, University of Vienna, 1090, Vienna, Austria
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McElwain JC, Matthaeus WJ, Barbosa C, Chondrogiannis C, O' Dea K, Jackson B, Knetge AB, Kwasniewska K, Nair R, White JD, Wilson JP, Montañez IP, Buckley YM, Belcher CM, Nogué S. Functional traits of fossil plants. THE NEW PHYTOLOGIST 2024; 242:392-423. [PMID: 38409806 DOI: 10.1111/nph.19622] [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: 09/10/2023] [Accepted: 12/19/2023] [Indexed: 02/28/2024]
Abstract
A minuscule fraction of the Earth's paleobiological diversity is preserved in the geological record as fossils. What plant remnants have withstood taphonomic filtering, fragmentation, and alteration in their journey to become part of the fossil record provide unique information on how plants functioned in paleo-ecosystems through their traits. Plant traits are measurable morphological, anatomical, physiological, biochemical, or phenological characteristics that potentially affect their environment and fitness. Here, we review the rich literature of paleobotany, through the lens of contemporary trait-based ecology, to evaluate which well-established extant plant traits hold the greatest promise for application to fossils. In particular, we focus on fossil plant functional traits, those measurable properties of leaf, stem, reproductive, or whole plant fossils that offer insights into the functioning of the plant when alive. The limitations of a trait-based approach in paleobotany are considerable. However, in our critical assessment of over 30 extant traits we present an initial, semi-quantitative ranking of 26 paleo-functional traits based on taphonomic and methodological criteria on the potential of those traits to impact Earth system processes, and for that impact to be quantifiable. We demonstrate how valuable inferences on paleo-ecosystem processes (pollination biology, herbivory), past nutrient cycles, paleobiogeography, paleo-demography (life history), and Earth system history can be derived through the application of paleo-functional traits to fossil plants.
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Affiliation(s)
- Jennifer C McElwain
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - William J Matthaeus
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Catarina Barbosa
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | | | - Katie O' Dea
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Bea Jackson
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Antonietta B Knetge
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Kamila Kwasniewska
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Richard Nair
- School of Natural Sciences, Botany, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Joseph D White
- Department of Biology, Baylor University, Waco, 76798-7388, TX, USA
| | - Jonathan P Wilson
- Department of Environmental Studies, Haverford College, Haverford, Pennsylvania, 19041, PA, USA
| | - Isabel P Montañez
- UC Davis Institute of the Environment, University of California, Davis, CA, 95616, USA
- Department of Earth and Planetary Sciences, University of California, Davis, CA, 95616, USA
| | - Yvonne M Buckley
- School of Natural Sciences, Zoology, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | | | - Sandra Nogué
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), 08193, Catalonia, Spain
- CREAF, Bellaterra (Cerdanyola del Vallès), 08193, Catalonia, Spain
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Tran VH, Nolting KM, Donovan LA, Temme AA. Cultivated sunflower ( Helianthus annuus L.) has lower tolerance of moderate drought stress than its con-specific wild relative, but the underlying traits remain elusive. PLANT DIRECT 2024; 8:e581. [PMID: 38585190 PMCID: PMC10995449 DOI: 10.1002/pld3.581] [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: 04/20/2023] [Revised: 02/29/2024] [Accepted: 03/03/2024] [Indexed: 04/09/2024]
Abstract
Cultivated crops are generally expected to have less abiotic stress tolerance than their wild relatives. However, this assumption is not well supported by empirical literature and may depend on the type of stress and how it is imposed, as well as the measure of tolerance being used. Here, we investigated whether wild and cultivated accessions of Helianthus annuus differed in stress tolerance assessed as proportional decline in biomass due to drought and whether wild and cultivated accessions differed in trait responses to drought and trait associations with tolerance. In a greenhouse study, H. annuus accessions in the two domestication classes (eight cultivated and eight wild accessions) received two treatments: a well-watered control and a moderate drought implemented as a dry down followed by maintenance at a predetermined soil moisture level with automated irrigation. Treatments were imposed at the seedling stage, and plants were harvested after 2 weeks of treatment. The proportional biomass decline in response to drought was 24% for cultivated H. annuus accessions but was not significant for the wild accessions. Thus, using the metric of proportional biomass decline, the cultivated accessions had less drought tolerance. Among accessions, there was no tradeoff between drought tolerance and vigor assessed as biomass in the control treatment. In a multivariate analysis, wild and cultivated accessions did not differ from each other or in response to drought for a subset of morphological, physiological, and allocational traits. Analyzed individually, traits varied in response to drought in wild and/or cultivated accessions, including declines in specific leaf area, leaf theoretical maximum stomatal conductance (gsmax), and stomatal pore length, but there was no treatment response for stomatal density, succulence, or the ability to osmotically adjust. Focusing on traits associations with tolerance, plasticity in gsmax was the most interesting because its association with tolerance differed by domestication class (although the effects were relatively weak) and thus might contribute to lower tolerance of cultivated sunflower. Our H. annuus results support the expectation that stress tolerance is lower in crops than wild relatives under some conditions. However, determining the key traits that underpin differences in moderate drought tolerance between wild and cultivated H. annuus remains elusive.
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Affiliation(s)
- Vivian H. Tran
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
| | | | - Lisa A. Donovan
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
| | - Andries A. Temme
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
- Department of Plant BreedingWageningen University & ResearchWageningenNetherlands
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Hu Y, Schäfer KVR, Hu S, Zhou W, Xiang D, Zeng Y, Ouyang S, Chen L, Lei P, Deng X, Zhao Z, Fang X, Xiang W. Woody species with higher hydraulic efficiency or lower photosynthetic capacity discriminate more against 13C at the global scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168172. [PMID: 37939937 DOI: 10.1016/j.scitotenv.2023.168172] [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: 07/21/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
Leaf carbon isotope composition (δ13C) provides an integrative record on the carbon and water balance of plants over long periods. Photosynthetic ability and hydraulic traits which are highly associated with stomatal behavior could affect leaf δ13C. Association between photosynthetic ability and leaf δ13C has been examined, however, how hydraulic traits influence leaf δ13C has not been fully understood. To fill this gap, we investigated the variations in leaf δ13C among 2591 woody species (547 shrub and 2044 tree species), and analyzed the link of leaf δ13C with leaf photosynthetic and xylem hydraulic traits. Our result showed that leaf δ13C was positively correlated to leaf photosynthetic ability and capacity. For hydraulic traits, leaf δ13C was negatively related to hydraulic conductivity (Ks), xylem pressure inducing 50 % loss of hydraulic conductivity (P50) and vessel diameter (Vdia). Associations of leaf δ13C with xylem hydraulic traits indicate woody species with stronger hydraulic safety discriminated less against 13C, while woody species with higher hydraulic efficiency had more negative leaf δ13C. Shrub species, which showed a lower Vdia and P50, had a significant less negative leaf δ13C than tree species. Furthermore, woody species inhabiting in dry regions discriminated less against 13C than those growing in humid regions. Moreover, leaf δ13C displayed a low phylogenetic signal based on Blomberg's K statistic. Overall, woody species with a higher leaf photosynthetic ability or stronger hydraulic safety system discriminated less against 13C and adopt the provident water use strategy.
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Affiliation(s)
- Yanting Hu
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Karina V R Schäfer
- Department of Earth and Environmental Sciences, Rutgers University, 195 University Avenue, Newark 07102, NJ, USA
| | - Songjiang Hu
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Wenneng Zhou
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
| | - Dong Xiang
- Forestry Bureau of Huaihua Perfecture, Huaihua 418099, Hunan, China
| | - Yelin Zeng
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Shuai Ouyang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Liang Chen
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Pifeng Lei
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Xiangwen Deng
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Zhonghui Zhao
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Xi Fang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China
| | - Wenhua Xiang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan 438107, China.
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Sun M, Niinemets Ü, Li Q, Jiao Y, Yao W, Shi P. An Inverse Scaling Relationship between Stomatal Density and Mean Nearest Neighbor Distance: Evidence from a Photinia Hybrid and One of Its Parents. PLANTS (BASEL, SWITZERLAND) 2023; 12:3701. [PMID: 37960057 PMCID: PMC10650524 DOI: 10.3390/plants12213701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023]
Abstract
Stomata are involved in transpiration and CO2 uptake by mediating gas exchange between internal plant tissues and the atmosphere. The capacity for gas exchange depends on stomatal density (SD), stomatal size, and pore dimensions. Most published work on stomatal quantification has assumed that stomatal distribution and stomatal density are spatially homogeneous across the leaf, but this assumption has been seldom tested. We selected 32 leaves from a Photinia hybrid, Photinia × fraseri 'Red Robin', and one of its parents, P. serratifolia. For each leaf, the leaf surface was divided into three or four equidistant layers along the apical-basal axis, and, in each layer, two positions, one closer to the midrib and the other closer to the leaf margin, were further selected. We calculated SD and mean nearest neighbor distance (MNND) for each lamina section and tested the scaling relationship between SD and MNND of the sampled stomatal centers using reduced major axis protocols. In addition, we calculated the stomatal aggregation index (SAI) for each lamina section to examine the spatial arrangement of stomata at the given size of field of view of 1.2 mm × 0.9 mm. We observed that SD decreased from the lamina apex towards the base for central lamina areas but varied little at leaf margins. An inverse scaling relationship between SD and MNND was observed for both species. This relationship could be used for SD estimation using the rapidly estimated trait, MNND. SAI did not vary significantly throughout leaf lamina, and the numerical values of SAI for all fields of view were greater than one, which indicates significant spatial repulsion between stomata. The study suggests that SD varies across leaf lamina to fine-tune plant water use and maximize carbon gain. However, spatial structures of stomata from different lamina sections exhibit similar patterns (i.e., spatial inhibition between stomata at small scales), probably due to hierarchical leaf vein patterns.
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Affiliation(s)
- Manli Sun
- Archives, Bamboo Research Institute, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; (M.S.); (Q.L.); (Y.J.); (W.Y.)
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 51006 Tartu, Estonia
- Estonian Academy of Sciences, 10130 Tallinn, Estonia
| | - Qiying Li
- Archives, Bamboo Research Institute, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; (M.S.); (Q.L.); (Y.J.); (W.Y.)
| | - Yabing Jiao
- Archives, Bamboo Research Institute, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; (M.S.); (Q.L.); (Y.J.); (W.Y.)
| | - Weihao Yao
- Archives, Bamboo Research Institute, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; (M.S.); (Q.L.); (Y.J.); (W.Y.)
| | - Peijian Shi
- Archives, Bamboo Research Institute, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; (M.S.); (Q.L.); (Y.J.); (W.Y.)
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Li Q, Liu X, Sun X, Zhao M, Liu L, Wang N, Gao Q, Fan P, Du N, Wang H, Wang R. Effects of drought hardening on the carbohydrate dynamics of Quercus acutissima seedlings under successional drought. FRONTIERS IN PLANT SCIENCE 2023; 14:1184584. [PMID: 37692418 PMCID: PMC10485557 DOI: 10.3389/fpls.2023.1184584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 08/09/2023] [Indexed: 09/12/2023]
Abstract
Introduction As precipitation patterns are predicted to become increasingly erratic, the functional maintenance of warm-temperate forests constitutes a key challenge for forest managers. In this study, 2-year-old Quercus acutissima seedlings were selected to elucidate the mechanisms whereby they respond to soil water fluctuations and the drought hardening effects on plant carbohydrate dynamics. Methods Seedlings were trained under different soil water conditions for 2 months: drought (D), well-watered (W), 1-month drought and then 1-month well-watered (D-W), and 1-month well-watered and then 1-month drought (W-D). The functional traits involved in water- and carbon-use strategies were explored at the end of the hardening period. Compared with seedlings in group W, seedlings in groups D, D-W, and W-D had increased potential for carbon uptake (i.e., light saturated point, maximum ribulose-1,5-bisphosphate (RuBP) saturated rate, and electron transport rate) and water uptake (i.e., fine root-to-coarse root ratio) and downregulated growth and mitochondrial respiration to decrease carbon consumption. After water fluctuation hardening, we performed a successional dry-down experiment for 1 month to detect carbohydrate dynamics and explore the acclimation caused by prior hardening. Results and discussion Our results revealed that there were more soluble sugars allocated in the leaves and more starch allocated in the stems and roots of seedlings hardened in the D, W-D, and D-W treatments than that of seedlings hardened in the W treatment. No significant changes in total non-structural carbohydrates were found. In addition, we found near-zero (seedlings trained by D and D-W treatments) or negative (seedlings trained by W-D treatment) growth of structural biomass at the end of the dry-down experiment, which was significantly lower than that of W-hardened seedlings. This suggests that there was a shift in allocation patterns between carbon storage and growth under recurrent soil drought, which can be strengthened by drought memory. We conclude that Q. acutissima seedlings adjusted water- and carbon-use strategies in response to water fluctuations, whereas stress memory can enhance their overall performance in reoccurring drought. Therefore, taking advantage of stress memory is a promising management strategy in forest nurseries, and drought-trained seedlings might be more suitable for afforestation practices in sites characterized by fluctuating soil water content, considering the ongoing global climatic changes.
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Affiliation(s)
- Qiang Li
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- School of Tropical Medicine, Hainan Medical University, Haikou, China
| | - Xiao Liu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
| | - Xinke Sun
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
| | - Mingming Zhao
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
| | - Lele Liu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
| | - Ning Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
| | - Qun Gao
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
| | - Peixian Fan
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
| | - Ning Du
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
| | - Hui Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
| | - Renqing Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
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Rathnasamy SA, Kambale R, Elangovan A, Mohanavel W, Shanmugavel P, Ramasamy G, Alagarsamy S, Marimuthu R, Rajagopalan VR, Manickam S, Ramanathan V, Muthurajan R, Vellingiri G. Altering Stomatal Density for Manipulating Transpiration and Photosynthetic Traits in Rice through CRISPR/Cas9 Mutagenesis. Curr Issues Mol Biol 2023; 45:3801-3814. [PMID: 37232714 DOI: 10.3390/cimb45050245] [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: 12/27/2022] [Revised: 02/12/2023] [Accepted: 02/28/2023] [Indexed: 05/27/2023] Open
Abstract
Stomata regulates conductance, transpiration and photosynthetic traits in plants. Increased stomatal density may contribute to enhanced water loss and thereby help improve the transpirational cooling process and mitigate the high temperature-induced yield losses. However, genetic manipulation of stomatal traits through conventional breeding still remains a challenge due to problems involved in phenotyping and the lack of suitable genetic materials. Recent advances in functional genomics in rice identified major effect genes determining stomatal traits, including its number and size. Widespread applications of CRISPR/Cas9 in creating targeted mutations paved the way for fine tuning the stomatal traits for enhancing climate resilience in crops. In the current study, attempts were made to create novel alleles of OsEPF1 (Epidermal Patterning Factor), a negative regulator of stomatal frequency/density in a popular rice variety, ASD 16, using the CRISPR/Cas9 approach. Evaluation of 17 T0 progenies identified varying mutations (seven multiallelic, seven biallelic and three monoallelic mutations). T0 mutant lines showed a 3.7-44.3% increase in the stomatal density, and all the mutations were successfully inherited into the T1 generation. Evaluation of T1 progenies through sequencing identified three homozygous mutants for one bp insertion. Overall, T1 plants showed 54-95% increased stomatal density. The homozygous T1 lines (# E1-1-4, # E1-1-9 and # E1-1-11) showed significant increase in the stomatal conductance (60-65%), photosynthetic rate (14-31%) and the transpiration rate (58-62%) compared to the nontransgenic ASD 16. Results demonstrated that the genetic alterations in OsEPF1 altered the stomatal density, stomatal conductance and photosynthetic efficiency in rice. Further experiments are needed to associate this technology with canopy cooling and high temperature tolerance.
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Affiliation(s)
- Sakthi Ambothi Rathnasamy
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Rohit Kambale
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Allimuthu Elangovan
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Williams Mohanavel
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Priyanka Shanmugavel
- Agro-Climatology Research Centre, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Gowtham Ramasamy
- Agro-Climatology Research Centre, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Senthil Alagarsamy
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Rajavel Marimuthu
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Veera Ranjani Rajagopalan
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Sudha Manickam
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | | | - Raveendran Muthurajan
- Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
| | - Geethalakshmi Vellingiri
- Agro-Climatology Research Centre, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India
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Wall S, Cockram J, Vialet-Chabrand S, Van Rie J, Gallé A, Lawson T. The impact of growth at elevated [CO2] on stomatal anatomy and behavior differs between wheat species and cultivars. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2860-2874. [PMID: 36633860 PMCID: PMC10134898 DOI: 10.1093/jxb/erad011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/11/2023] [Indexed: 06/06/2023]
Abstract
The ability of plants to respond to changes in the environment is crucial to their survival and reproductive success. The impact of increasing the atmospheric CO2 concentration (a[CO2]), mediated by behavioral and developmental responses of stomata, on crop performance remains a concern under all climate change scenarios, with potential impacts on future food security. To identify possible beneficial traits that could be exploited for future breeding, phenotypic variation in morphological traits including stomatal size and density, as well as physiological responses and, critically, the effect of growth [CO2] on these traits, was assessed in six wheat relative accessions (including Aegilops tauschii, Triticum turgidum ssp. Dicoccoides, and T. turgidum ssp. dicoccon) and five elite bread wheat T. aestivum cultivars. Exploiting a range of different species and ploidy, we identified key differences in photosynthetic capacity between elite hexaploid wheat and wheat relatives. We also report differences in the speed of stomatal responses which were found to be faster in wheat relatives than in elite cultivars, a trait that could be useful for enhanced photosynthetic carbon gain and water use efficiency. Furthermore, these traits do not all appear to be influenced by elevated [CO2], and determining the underlying genetics will be critical for future breeding programmes.
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Affiliation(s)
- Shellie Wall
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - James Cockram
- NIAB, 93 Lawrence Weaver Road, Cambridge CB3 0LE, UK
| | | | - Jeroen Van Rie
- BASF Belgium Coordination Center CommV-Innovation Center Gent, Technologiepark-Zwijnaarde 101, 9052 Gent, Belgium
| | - Alexander Gallé
- BASF Belgium Coordination Center CommV-Innovation Center Gent, Technologiepark-Zwijnaarde 101, 9052 Gent, Belgium
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9
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Jiang GF, Li SY, Dinnage R, Cao KF, Simonin KA, Roddy AB. Diverse mangroves deviate from other angiosperms in their genome size, leaf cell size and cell packing density relationships. ANNALS OF BOTANY 2023; 131:347-360. [PMID: 36516425 PMCID: PMC9992938 DOI: 10.1093/aob/mcac151] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS While genome size limits the minimum sizes and maximum numbers of cells that can be packed into a given leaf volume, mature cell sizes can be substantially larger than their meristematic precursors and vary in response to abiotic conditions. Mangroves are iconic examples of how abiotic conditions can influence the evolution of plant phenotypes. METHODS Here, we examined the coordination between genome size, leaf cell sizes, cell packing densities and leaf size in 13 mangrove species across four sites in China. Four of these species occurred at more than one site, allowing us to test the effect of climate on leaf anatomy. RESULTS We found that genome sizes of mangroves were very small compared to other angiosperms, but, like other angiosperms, mangrove cells were always larger than the minimum size defined by genome size. Increasing mean annual temperature of a growth site led to higher packing densities of veins (Dv) and stomata (Ds) and smaller epidermal cells but had no effect on stomatal size. In contrast to other angiosperms, mangroves exhibited (1) a negative relationship between guard cell size and genome size; (2) epidermal cells that were smaller than stomata; and (3) coordination between Dv and Ds that was not mediated by epidermal cell size. Furthermore, mangrove epidermal cell sizes and packing densities covaried with leaf size. CONCLUSIONS While mangroves exhibited coordination between veins and stomata and attained a maximum theoretical stomatal conductance similar to that of other angiosperms, the tissue-level tradeoffs underlying these similar relationships across species and environments were markedly different, perhaps indicative of the unique structural and physiological adaptations of mangroves to their stressful environments.
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Affiliation(s)
| | - Su-Yuan Li
- Guangxi Key Laboratory of Forest Ecology and Conservation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004, PR China
| | - Russell Dinnage
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, FL 33199USA
| | - Kun-Fang Cao
- Guangxi Key Laboratory of Forest Ecology and Conservation, and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004, PR China
| | - Kevin A Simonin
- Department of Biology, San Francisco State University, San Francisco, CA 94132USA
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10
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Zhou F, Matthew C, Yang P, Huang Y, Nie B, Nan Z. Leaf morphology, functional trait and altitude response in perennial vetch (Vicia unijuga A. Braun), alfalfa (Medicago sativa L.) and sainfoin (Onobrychis viciifolia Scop.). PLANTA 2023; 257:75. [PMID: 36879140 DOI: 10.1007/s00425-023-04098-z] [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: 11/11/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Species have plasticity across altitude gradients in leaf morphology and function, and their response to high altitude conditions was mainly reflected in leaf cell metabolism and gas exchange. Leaf morphological and functional adaptation to altitude has received research attention in recent years, but there are no studies for forage legumes. Here we report differences in 39 leaf morphology and functional traits of three leguminous forages (alfalfa, sainfoin and perennial vetch) at three sites in Gansu Province, China, ranging from 1768 to 3074 m altitude to provide information for potential use in breeding programmes. With increasing altitude, plant water status increased, reflecting increase in soil water content and decreased average temperature, which lead to leaf intercellular CO2 concentration. Stomatal conductance and evapotranspiration increased significantly but water-use efficiency decreased. At high altitude, ΦPSII decreased but non-photochemical quenching and chlorophyll a:b ratio increased while spongy mesophyll tissue and leaf thickness increased. These changes may be due to UV or low-temperature damage of leaf protein and metabolic cost of plant protection or defence responses. Contrary to many other studies, leaf mass per area decreased significantly at higher altitude. This was consistent with predictions under the worldwide leaf economic spectrum on the basis that soil nutrients increased with increasing altitude. The key species differences were more irregularly shaped epidermal cells and larger stomatal size in perennial vetch compared to alfalfa or sainfoin that enhanced gas exchange and photosynthesis by generating mechanical force, increasing guard cell turgor, and promoting stomatal operation. The lower adaxial stomatal density also enhanced water-use efficiency. These adaptations might confer perennial vetch an advantage in environments with extreme diurnal temperature fluctuation or in frigid conditions.
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Affiliation(s)
- Fangfang Zhou
- State Key Laboratory of Grassland Agroecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, 730020, Gansu, China
| | - Cory Matthew
- School of Agriculture and Environment, College of Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Pengfei Yang
- School of Life Sciences, Lanzhou University, Lanzhou, 730020, Gansu, China
| | - Yafeng Huang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230031, Anhui, China
| | - Bin Nie
- State Key Laboratory of Grassland Agroecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, 730020, Gansu, China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agroecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, 730020, Gansu, China.
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11
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Zhang M, Gao H, Chen S, Wang X, Mo W, Yang X, Wang X, Wang Z, Wang R. Linkages between stomatal density and minor leaf vein density across different altitudes and growth forms. FRONTIERS IN PLANT SCIENCE 2022; 13:1064344. [PMID: 36561450 PMCID: PMC9765094 DOI: 10.3389/fpls.2022.1064344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Water supply and demand in leaves are primarily determined by stomatal density (SD, water demand) and minor leaf vein density (VLA, water supply). Thus, covariation between them is essential for maintaining water balance. However, there is debate over whether these two traits vary in a coordinated way. Here, we gathered SD and VLA data from 194 species over four altitudinal gradients, and investigated their relationships across all species, growth forms, and different altitudes. Our findings demonstrated that SD and VLA were positively associated across all species, independent on plant phylogeny. Moreover, the reliability of this SD-VLA relationship increased with altitudes. Although the stomatal number per minor vein length (SV) remained stable across different altitudes and growth forms, the positive SD-VLA relationship was found only in shrubs and herbs, but not in trees. Differently, a strong coordination between total stomatal number and total leaf vein length was observed across all species, trees, shrubs and herbs. These findings suggested that coordinating stomatal number and minor vein length within one leaf, rather than stomatal and vein density, may be a common choice of plants in the fluctuating environment. Therefore, to explore the relationship between total number of stomata and total length of leaf veins seems to better reflect the linkage between stomata and leaf veins, especially when covering different growth forms.
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Affiliation(s)
- Ming Zhang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Huirong Gao
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Shuang Chen
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaochun Wang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Weiyi Mo
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Xue Yang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Xue Wang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhibo Wang
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi, China
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, China
| | - Ruili Wang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
- Qinling National Forest Ecosystem Research Station, Yangling, Shaanxi, China
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12
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Liu C, Sack L, Li Y, He N. Contrasting adaptation and optimization of stomatal traits across communities at continental scale. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6405-6416. [PMID: 35716087 DOI: 10.1093/jxb/erac266] [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: 12/01/2021] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Shifts in stomatal trait distributions across contrasting environments and their linkage with ecosystem productivity at large spatial scales have been unclear. Here, we measured the maximum stomatal conductance (g), stomatal area fraction (f), and stomatal space-use efficiency (e, the ratio of g to f) of 800 plant species ranging from tropical to cold-temperate forests, and determined their values for community-weighted mean, variance, skewness, and kurtosis. We found that the community-weighted means of g and f were higher in drier sites, and thus, that drought 'avoidance' by water availability-driven growth pulses was the dominant mode of adaptation for communities at sites with low water availability. Additionally, the variance of g and f was also higher at arid sites, indicating greater functional niche differentiation, whereas that for e was lower, indicating the convergence in efficiency. When all other stomatal trait distributions were held constant, increasing kurtosis or decreasing skewness of g would improve ecosystem productivity, whereas f showed the opposite patterns, suggesting that the distributions of inter-related traits can play contrasting roles in regulating ecosystem productivity. These findings demonstrate the climatic trends of stomatal trait distributions and their significance in the prediction of ecosystem productivity.
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Affiliation(s)
- Congcong Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90025, USA
| | - Ying Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Nianpeng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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13
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Rivera BK, Sáez PL, Cavieres LA, Capó-Bauçà S, Iñiguez C, Sanfuentes von Stowasser E, Fuentes F, Ramírez CF, Vallejos V, Galmés J. Anatomical and biochemical evolutionary ancient traits of Araucaria araucana (Molina) K. Koch and their effects on carbon assimilation. TREE PHYSIOLOGY 2022; 42:1957-1974. [PMID: 35604362 DOI: 10.1093/treephys/tpac057] [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: 10/03/2021] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The study of ancient species provides valuable information concerning the evolution of specific adaptations to past and current environmental conditions. Araucaria araucana (Molina) K. Koch belongs to one of the oldest families of conifers in the world, but despite this, there are few studies focused on its physiology and responses to changes in environmental conditions. We used an integrated approach aimed at comprehensively characterizing the ecophysiology of this poorly known species, focusing in its stomatal, mesophyll and biochemical traits, hypothesizing that these traits govern the carbon assimilation of A. araucana under past and present levels of atmospheric CO2. Results indicated that A. araucana presents the typical traits of an ancient species, such as large stomata and low stomatal density, which trigger low stomatal conductance and slow stomatal responsiveness to changing environmental conditions. Interestingly, the quantitative analysis showed that photosynthetic rates were equally limited by both diffusive and biochemical components. The Rubisco catalytic properties proved to have a low Rubisco affinity for CO2 and O2, similar to other ancient species. This affinity for CO2, together with the low carboxylation turnover rate, are responsible for the low Rubisco catalytic efficiency of carboxylation. These traits could be the result of the diverse environmental selective pressures that A. araucana was exposed during its diversification. The increase in measured temperatures induced an increase in stomatal and biochemical limitations, which together with a lower Rubisco affinity for CO2 could explain the low photosynthetic capacity of A. araucana in warmer conditions.
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Affiliation(s)
- Betsy K Rivera
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Patricia L Sáez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
- Instituto de Ecología y Biodiversidad (IEB), Santiago 8320000, Chile
| | - Lohengrin A Cavieres
- Instituto de Ecología y Biodiversidad (IEB), Santiago 8320000, Chile
- ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4030000, Chile
| | - Sebastià Capó-Bauçà
- Research Group on Plant Biology under Mediterranean Conditions, INAGEA-Universitat de les Illes Balears, Balearic Islands 07122, Spain
| | - Concepción Iñiguez
- Research Group on Plant Biology under Mediterranean Conditions, INAGEA-Universitat de les Illes Balears, Balearic Islands 07122, Spain
| | - Eugenio Sanfuentes von Stowasser
- Laboratorio de Patología Forestal, Facultad Ciencias Forestales y Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Francisca Fuentes
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Constanza F Ramírez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Valentina Vallejos
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, Departamento de Silvicultura, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, INAGEA-Universitat de les Illes Balears, Balearic Islands 07122, Spain
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14
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Mueller KE, Ocheltree TW, Kray JA, Bushey JA, Blumenthal DM, Williams DG, Pendall E. Trading water for carbon in the future: Effects of elevated CO 2 and warming on leaf hydraulic traits in a semiarid grassland. GLOBAL CHANGE BIOLOGY 2022; 28:5991-6001. [PMID: 35751572 PMCID: PMC9544398 DOI: 10.1111/gcb.16314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
The effects of climate change on plants and ecosystems are mediated by plant hydraulic traits, including interspecific and intraspecific variability of trait phenotypes. Yet, integrative and realistic studies of hydraulic traits and climate change are rare. In a semiarid grassland, we assessed the response of several plant hydraulic traits to elevated CO2 (+200 ppm) and warming (+1.5 to 3°C; day to night). For leaves of five dominant species (three graminoids and two forbs), and in replicated plots exposed to 7 years of elevated CO2 , warming, or ambient climate, we measured: stomatal density and size, xylem vessel size, turgor loss point, and water potential (pre-dawn). Interspecific differences in hydraulic traits were larger than intraspecific shifts induced by elevated CO2 and/or warming. Effects of elevated CO2 were greater than effects of warming, and interactions between treatments were weak or not detected. The forbs showed little phenotypic plasticity. The graminoids had leaf water potentials and turgor loss points that were 10% to 50% less negative under elevated CO2 ; thus, climate change might cause these species to adjust their drought resistance strategy away from tolerance and toward avoidance. The C4 grass also reduced allocation of leaf area to stomata under elevated CO2 , which helps explain observations of higher soil moisture. The shifts in hydraulic traits under elevated CO2 were not, however, simply due to higher soil moisture. Integration of our results with others' indicates that common species in this grassland are more likely to adjust stomatal aperture in response to near-term climate change, rather than anatomical traits; this contrasts with apparent effects of changing CO2 on plant anatomy over evolutionary time. Future studies should assess how plant responses to drought may be constrained by the apparent shift from tolerance (via low turgor loss point) to avoidance (via stomatal regulation and/or access to deeper soil moisture).
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Affiliation(s)
- Kevin E. Mueller
- Department of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Troy W. Ocheltree
- Department of Forest and Rangeland StewardshipColorado State UniversityFort CollinsColoradoUSA
| | - Julie A. Kray
- Rangeland Resources & Systems Research, Agricultural Research Service, United States Department of AgricultureFort CollinsColoradoUSA
| | - Julie A. Bushey
- Water Management Research, Agricultural Research Service, United States Department of AgricultureFort CollinsColoradoUSA
| | - Dana M. Blumenthal
- Rangeland Resources & Systems Research, Agricultural Research Service, United States Department of AgricultureFort CollinsColoradoUSA
| | | | - Elise Pendall
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
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15
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Meng YY, Xiang W, Wen Y, Huang DL, Cao KF, Zhu SD. Correlations between leaf economics, mechanical resistance and drought tolerance across 41 cycad species. ANNALS OF BOTANY 2022; 130:345-354. [PMID: 34871356 PMCID: PMC9486883 DOI: 10.1093/aob/mcab146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/04/2021] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIMS We conducted a comprehensive analysis of the functional traits of leaves (leaflets) of cycads. The aim of this study was to clarify the functional divergence between the earlier origin Cycadaceae and the later differentiated Zamiaceae, and the differences in trait associations between cycads and angiosperms. METHODS We selected 20 Cycadaceae species and 21 Zamiaceae species from the same cycad garden in South China, and measured their leaf structure, economic traits, mechanical resistance (Fp) and leaf water potential at the turgor loss point (πtlp). In addition, we compiled a dataset of geographical distribution along with climatic variables for these cycad species, and some leaf traits of tropical-sub-tropical angiosperm woody species from the literature for comparison. KEY RESULTS The results showed significantly contrasting leaf trait syndromes between the two families, with Zamiaceae species exhibiting thicker leaves, higher carbon investments and greater Fp than Cycadaceae species. Leaf thickness (LT) and πtlp were correlated with mean climatic variables in their native distribution ranges, indicating their evolutionary adaptation to environmental conditions. Compared with the leaves of angiosperms, the cycad leaves were thicker and tougher, and more tolerant to desiccation. Greater Fp was associated with a higher structural investment in both angiosperms and cycads; however, cycads showed lower Fp at a given leaf mass per area or LT than angiosperms. Enhancement of Fp led to more negative πtlp in angiosperms, but the opposite trend was observed in cycads. CONCLUSIONS Our results reveal that variations in leaf traits of cycads are mainly influenced by taxonomy and the environment of their native range. We also demonstrate similar leaf functional associations in terms of economics, but different relationships with regard to mechanics and drought tolerance between cycads and angiosperms. This study expands our understanding of the ecological strategies and likely responses of cycads to future climate change.
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Affiliation(s)
| | | | | | - Dong-Liu Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
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16
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Wall S, Vialet‐Chabrand S, Davey P, Van Rie J, Galle A, Cockram J, Lawson T. Stomata on the abaxial and adaxial leaf surfaces contribute differently to leaf gas exchange and photosynthesis in wheat. THE NEW PHYTOLOGIST 2022; 235:1743-1756. [PMID: 35586964 PMCID: PMC9545378 DOI: 10.1111/nph.18257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/06/2022] [Indexed: 05/12/2023]
Abstract
Although stomata are typically found in greater numbers on the abaxial surface, wheat flag leaves have greater densities on the adaxial surface. We determine the impact of this less common stomatal patterning on gaseous fluxes using a novel chamber that simultaneously measures both leaf surfaces. Using a combination of differential illuminations and CO2 concentrations at each leaf surface, we found that mesophyll cells associated with the adaxial leaf surface have a higher photosynthetic capacity than those associated with the abaxial leaf surface, which is supported by an increased stomatal conductance (driven by differences in stomatal density). When vertical gas flux at the abaxial leaf surface was blocked, no compensation by adaxial stomata was observed, suggesting each surface operates independently. Similar stomatal kinetics suggested some co-ordination between the two surfaces, but factors other than light intensity played a role in these responses. Higher photosynthetic capacity on the adaxial surface facilitates greater carbon assimilation, along with higher adaxial stomatal conductance, which would also support greater evaporative leaf cooling to maintain optimal leaf temperatures for photosynthesis. Furthermore, abaxial gas exchange contributed c. 50% to leaf photosynthesis and therefore represents an important contributor to overall leaf gas exchange.
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Affiliation(s)
- Shellie Wall
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
| | | | - Phillip Davey
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
| | - Jeroen Van Rie
- BASF BBCC – Innovation Center GentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | - Alexander Galle
- BASF BBCC – Innovation Center GentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | | | - Tracy Lawson
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
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17
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Xie J, Wang Z, Li Y. Stomatal opening ratio mediates trait coordinating network adaptation to environmental gradients. THE NEW PHYTOLOGIST 2022; 235:907-922. [PMID: 35491493 DOI: 10.1111/nph.18189] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
A trait coordination network is constructed through intercorrelations of functional traits, which reflect trait-based adaptive strategies. However, little is known about how these networks change across spatial scales, and what drivers and mechanisms mediate this change. This study bridges that gap by integrating functional traits related to plant carbon gain and water economy into the coordination network of Siberian elm (Ulmus pumila), a eurybiont that survives along a 3800 km environmental gradient from humid forest to arid desert. Our results demonstrated that both stomatal density and stomatal size reached a physiological threshold at which adjustments in these traits were not sufficient to cope with the increased environmental stress. Network analysis further revealed that the mechanism for overcoming this threshold, the stomatal opening ratio, gratio , was represented by the highest values for centrality across different spatial scales, and therefore mediated the changes in the trait coordination network along environmental gradients. The mediating roles manifested as creating the highest maximum theoretical stomatal conductance (gsmax ) but lowest possible gratio for pathogen defense in humid regions, while maintaining the gratio 'sweet spot' (c. 20% in this region) for highest water use efficiency in semihumid regions, and having the lowest gsmax and highest gratio for gas exchange and leaf cooling in arid regions. These results suggested that the stomatal traits related to control of stomatal movement play fundamental roles in balancing gas exchange, leaf cooling, embolism resistance and pathogen defense. These insights will allow more accurate model parameterization for different regions, and therefore better predictions of species' responses to global change.
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Affiliation(s)
- Jiangbo Xie
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Zhongyuan Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Yan Li
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
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18
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Faralli M, Bontempo L, Bianchedi PL, Moser C, Bertamini M, Lawson T, Camin F, Stefanini M, Varotto C. Natural variation in stomatal dynamics drives divergence in heat stress tolerance and contributes to seasonal intrinsic water-use efficiency in Vitis vinifera (subsp. sativa and sylvestris). JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3238-3250. [PMID: 34929033 DOI: 10.1093/jxb/erab552] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 12/20/2021] [Indexed: 05/20/2023]
Abstract
Stomata control CO2 uptake for photosynthesis and water loss through transpiration, thus playing a key role in leaf thermoregulation, water-use efficiency (iWUE), and plant productivity. In this work, we investigated the relationship between several leaf traits and hypothesized that stomatal behavior to fast (i.e. minutes) environmental changes co-determines, along with steady-state traits, the physiological response of grapevine to the surrounding fluctuating environment over the growing season. No relationship between iWUE, heat stress tolerance, and stomatal traits was observed in field-grown grapevine, suggesting that other physiological mechanisms are involved in determining leaf evaporative cooling capacity and the seasonal ratio of CO2 uptake (A) to stomatal conductance (gs). Indeed, cultivars that in the field had an unexpected combination of high iWUE but low sensitivity to thermal stress displayed a quick stomatal closure to light, but a sluggish closure to increased vapor pressure deficit (VPD) levels. This strategy, aiming both at conserving water under a high to low light transition and in prioritizing evaporative cooling under a low to high VPD transition, was mainly observed in the cultivars Regina and Syrah. Moreover, cultivars with different known responses to soil moisture deficit or high air VPD (isohydric versus anisohydric) had opposite behavior under fluctuating environments, with the isohydric cultivar showing slow stomatal closure to reduced light intensity but quick temporal responses to VPD manipulation. We propose that stomatal behavior to fast environmental fluctuations can play a critical role in leaf thermoregulation and water conservation under natural field conditions in grapevine.
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Affiliation(s)
- Michele Faralli
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
- Center Agriculture Food Environment (C3A), University of Trento, Via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Luana Bontempo
- Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Pier Luigi Bianchedi
- Technology Transfer Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Claudio Moser
- Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Massimo Bertamini
- Center Agriculture Food Environment (C3A), University of Trento, Via Mach 1, 38098 San Michele all'Adige (TN), Italy
- Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK
| | - Federica Camin
- Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
- Center Agriculture Food Environment (C3A), University of Trento, Via Mach 1, 38098 San Michele all'Adige (TN), Italy
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, A-1400 Vienna, Austria
| | - Marco Stefanini
- Genomics and Biology of Fruit Crops Department, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
| | - Claudio Varotto
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, via Mach 1, 38098 San Michele all'Adige (TN), Italy
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Pereira JP, Garbin ML, Carrijo TT, da Silva JA, Bourguignon TP, Cavatte PC. Lack of coordination between stomatal and vein traits provides functional benefits to the dioecious tropical tree Myrsine coriacea. PHYSIOLOGIA PLANTARUM 2022; 174:e13719. [PMID: 35587454 DOI: 10.1111/ppl.13719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/25/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Climate change will affect the distribution of many tropical plant species. However, the understanding of how dioecious tropical species cope with different environmental conditions is still limited. To address this issue, we investigated how secondary trait attributes in populations of the dioecious tropical tree Myrsine coriacea change along an altitudinal gradient. Eighty individual plants (40 male and 40 female) were selected among seven natural populations. Leaf variation in morphological and stomatal traits, and carbon and nitrogen isotopic compositions were analyzed. Female plants had greater isotopic leaf carbon composition (δ13 C) and nitrogen content than male plants, increasing their carboxylation capacity. Plants of both sexes had smaller stomata, greater water-use efficiency (greater δ13 C), and greater nitrogen isotopic composition (δ15 N) at higher altitudes. They also showed lower δ15 N and had greater carbon: nitrogen ratios at lower altitudes. There was a lack of coordination between stomatal and vein traits, which was compensated for by variation in specific leaf areas. This mechanism was essential for increasing plant performance under the limiting conditions found by the species at higher altitudes.
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Affiliation(s)
- Jéssica Priscilla Pereira
- Programa de Pós-graduação em Biologia Vegetal, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Mário Luís Garbin
- Laboratório de Botânica, Departamento de Biologia, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
| | - Tatiana Tavares Carrijo
- Laboratório de Botânica, Departamento de Biologia, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
| | - Josimar Aleixo da Silva
- Laboratório de Botânica, Departamento de Biologia, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
- Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural, Cachoeiro de Itapemirim, Alegre, ES, Brazil
| | - Tayna Poppe Bourguignon
- Laboratório de Botânica, Departamento de Biologia, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
| | - Paulo Cezar Cavatte
- Programa de Pós-graduação em Biologia Vegetal, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
- Laboratório de Botânica, Departamento de Biologia, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
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20
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Zhang N, Berman SR, Joubert D, Vialet-Chabrand S, Marcelis LFM, Kaiser E. Variation of Photosynthetic Induction in Major Horticultural Crops Is Mostly Driven by Differences in Stomatal Traits. FRONTIERS IN PLANT SCIENCE 2022; 13:860229. [PMID: 35574072 PMCID: PMC9094112 DOI: 10.3389/fpls.2022.860229] [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: 01/22/2022] [Accepted: 03/14/2022] [Indexed: 06/15/2023]
Abstract
Under natural conditions, irradiance frequently fluctuates, causing net photosynthesis rate (A) to respond slowly and reducing the yields. We quantified the genotypic variation of photosynthetic induction in 19 genotypes among the following six horticultural crops: basil, chrysanthemum, cucumber, lettuce, tomato, and rose. Kinetics of photosynthetic induction and the stomatal opening were measured by exposing shade-adapted leaves (50 μmol m-2 s-1) to a high irradiance (1000 μmol m-2 s-1) until A reached a steady state. Rubisco activation rate was estimated by the kinetics of carboxylation capacity, which was quantified using dynamic A vs. [CO2] curves. Generally, variations in photosynthetic induction kinetics were larger between crops and smaller between cultivars of the same crop. Time until reaching 20-90% of full A induction varied by 40-60% across genotypes, and this was driven by a variation in the stomatal opening rather than Rubisco activation kinetics. Stomatal conductance kinetics were partly determined by differences in the stomatal size and density; species with densely packed, smaller stomata (e.g., cucumber) tended to open their stomata faster, adapting stomatal conductance more rapidly and efficiently than species with larger but fewer stomata (e.g., chrysanthemum). We conclude that manipulating stomatal traits may speed up photosynthetic induction and growth of horticultural crops under natural irradiance fluctuations.
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Affiliation(s)
- Ningyi Zhang
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
| | - Sarah R. Berman
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
| | - Dominique Joubert
- Biometris, Department of Mathematical and Statistical Methods, Wageningen University & Research, Wageningen, Netherlands
| | - Silvere Vialet-Chabrand
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
| | - Leo F. M. Marcelis
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
| | - Elias Kaiser
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
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21
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Benton MJ, Wilf P, Sauquet H. The Angiosperm Terrestrial Revolution and the origins of modern biodiversity. THE NEW PHYTOLOGIST 2022; 233:2017-2035. [PMID: 34699613 DOI: 10.1111/nph.17822] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
Biodiversity today has the unusual property that 85% of plant and animal species live on land rather than in the sea, and half of these live in tropical rainforests. An explosive boost to terrestrial diversity occurred from c. 100-50 million years ago, the Late Cretaceous and early Palaeogene. During this interval, the Earth-life system on land was reset, and the biosphere expanded to a new level of productivity, enhancing the capacity and species diversity of terrestrial environments. This boost in terrestrial biodiversity coincided with innovations in flowering plant biology and evolutionary ecology, including their flowers and efficiencies in reproduction; coevolution with animals, especially pollinators and herbivores; photosynthetic capacities; adaptability; and ability to modify habitats. The rise of angiosperms triggered a macroecological revolution on land and drove modern biodiversity in a secular, prolonged shift to new, high levels, a series of processes we name here the Angiosperm Terrestrial Revolution.
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Affiliation(s)
- Michael J Benton
- School of Earth Sciences, Life Sciences Building, University of Bristol, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Peter Wilf
- Department of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, 16802, USA
| | - Hervé Sauquet
- National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust, Sydney, NSW, 2000, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
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22
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Rahman AANS, Rahman M, Shimanto MH, Kibria MG, Islam M. Stomatal size and density trade-off varies with leaf phenology and species shade tolerance in a South Asian moist tropical forest. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:307-318. [PMID: 35130475 DOI: 10.1071/fp21159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
The density and guard cell length of stomata regulate the physiological processes in plants. Yet, the variation of stomatal characteristics among different functional groups of trees is not been well understood. Particularly, a comprehensive understanding of stomatal behaviour in Bangladeshi moist forest trees is lacking. The study investigated how abaxial stomatal density (SD) and guard cell length (GCL) vary among tree functional types and leaf phenological groups in a moist tropical forest of Bangladesh. Cluster dendrogram revealed three groups of species based on SD and GCL. The independent sample t -test showed that there was a significant difference in SD between evergreen and deciduous tree species (t =4.18, P <0.001) but no significant difference in GCL between the two phenological groups. ANOVA revealed no significant difference in SD among the light demanding, intermediate shade tolerant and shade tolerant species (F =0.76, P =0.47). However, GCL significantly differed among the three functional groups (F =3.3, P <0.05). Maximum theoretical stomatal conductance (g max ) varied between evergreen and deciduous species but did not vary with species shade tolerance. In general, there was a significant trade-off between SD and GCL. However, the inverse relationship was stronger in deciduous and shade tolerant species than in evergreen and shade intolerant species. Leaf dry matter content was positively related with SD and negatively related with GCL. Specific leaf area and leaf thickness were not related to the stomatal traits. Our analyses suggest that leaf phenology and species shade tolerance need to be considered while estimating gas exchange through the stomata in tropical moist forests.
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Affiliation(s)
- Abdullah Al-Nur Shanto Rahman
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Mizanur Rahman
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Mehedi Hasan Shimanto
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Mohammad Golam Kibria
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Mahmuda Islam
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
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23
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Marchin RM, Backes D, Ossola A, Leishman MR, Tjoelker MG, Ellsworth DS. Extreme heat increases stomatal conductance and drought-induced mortality risk in vulnerable plant species. GLOBAL CHANGE BIOLOGY 2022; 28:1133-1146. [PMID: 34741566 PMCID: PMC9299030 DOI: 10.1111/gcb.15976] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/12/2021] [Accepted: 10/27/2021] [Indexed: 05/29/2023]
Abstract
Tree mortality during global-change-type drought is usually attributed to xylem dysfunction, but as climate change increases the frequency of extreme heat events, it is necessary to better understand the interactive role of heat stress. We hypothesized that some drought-stressed plants paradoxically open stomata in heatwaves to prevent leaves from critically overheating. We experimentally imposed heat (>40°C) and drought stress onto 20 broadleaf evergreen tree/shrub species in a glasshouse study. Most well-watered plants avoided lethal overheating, but drought exacerbated thermal damage during heatwaves. Thermal safety margins (TSM) quantifying the difference between leaf surface temperature and leaf critical temperature, where photosynthesis is disrupted, identified species vulnerability to heatwaves. Several mechanisms contributed to high heat tolerance and avoidance of damaging leaf temperatures-small leaf size, low leaf osmotic potential, high leaf mass per area (i.e., thick, dense leaves), high transpirational capacity, and access to water. Water-stressed plants had smaller TSM, greater crown dieback, and a fundamentally different stomatal heatwave response relative to well-watered plants. On average, well-watered plants closed stomata and decreased stomatal conductance (gs ) during the heatwave, but droughted plants did not. Plant species with low gs , either due to isohydric stomatal behavior under water deficit or inherently low transpirational capacity, opened stomata and increased gs under high temperatures. The current paradigm maintains that stomata close before hydraulic thresholds are surpassed, but our results suggest that isohydric species may dramatically increase gs (over sixfold increases) even past their leaf turgor loss point. By actively increasing water loss at high temperatures, plants can be driven toward mortality thresholds more rapidly than has been previously recognized. The inclusion of TSM and responses to heat stress could improve our ability to predict the vulnerability of different tree species to future droughts.
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Affiliation(s)
- Renée M. Marchin
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Diana Backes
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Alessandro Ossola
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Michelle R. Leishman
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Mark G. Tjoelker
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - David S. Ellsworth
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
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24
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Brendel O, Epron D. Are differences among forest tree populations in carbon isotope composition an indication of adaptation to drought? TREE PHYSIOLOGY 2022; 42:26-31. [PMID: 34726246 DOI: 10.1093/treephys/tpab143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Oliver Brendel
- Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy F-54000, France
| | - Daniel Epron
- Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy F-54000, France
- Kyoto University, Graduate School of Agriculture, Kyoto 606-8502, Japan
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25
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Gibbs JA, Mcausland L, Robles-Zazueta CA, Murchie EH, Burgess AJ. A Deep Learning Method for Fully Automatic Stomatal Morphometry and Maximal Conductance Estimation. FRONTIERS IN PLANT SCIENCE 2021; 12:780180. [PMID: 34925424 PMCID: PMC8675901 DOI: 10.3389/fpls.2021.780180] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/01/2021] [Indexed: 06/14/2023]
Abstract
Stomata are integral to plant performance, enabling the exchange of gases between the atmosphere and the plant. The anatomy of stomata influences conductance properties with the maximal conductance rate, g smax, calculated from density and size. However, current calculations of stomatal dimensions are performed manually, which are time-consuming and error prone. Here, we show how automated morphometry from leaf impressions can predict a functional property: the anatomical gsmax. A deep learning network was derived to preserve stomatal morphometry via semantic segmentation. This forms part of an automated pipeline to measure stomata traits for the estimation of anatomical gsmax. The proposed pipeline achieves accuracy of 100% for the distinction (wheat vs. poplar) and detection of stomata in both datasets. The automated deep learning-based method gave estimates for gsmax within 3.8 and 1.9% of those values manually calculated from an expert for a wheat and poplar dataset, respectively. Semantic segmentation provides a rapid and repeatable method for the estimation of anatomical gsmax from microscopic images of leaf impressions. This advanced method provides a step toward reducing the bottleneck associated with plant phenotyping approaches and will provide a rapid method to assess gas fluxes in plants based on stomata morphometry.
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Affiliation(s)
- Jonathon A. Gibbs
- School of Computer Science, University of Nottingham, Nottingham, United Kingdom
| | - Lorna Mcausland
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | | | - Erik H. Murchie
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
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26
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Shi P, Jiao Y, Diggle PJ, Turner R, Wang R, Niinemets Ü. Spatial distribution characteristics of stomata at the areole level in Michelia cavaleriei var. platypetala (Magnoliaceae). ANNALS OF BOTANY 2021; 128:875-886. [PMID: 34397092 PMCID: PMC8577203 DOI: 10.1093/aob/mcab106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/13/2021] [Indexed: 05/21/2023]
Abstract
BACKGROUND AND AIMS In hierarchically reticulate venation patterns, smaller orders of veins form areoles in which stomata are located. This study aimed to quantify the spatial relationship among stomata at the areole level. METHODS For each of 12 leaves of M. cavaleriei var. platypetala, we assumed that stomatal characteristics were symmetrical on either side of the midrib, and divided the leaf surface on one side of the midrib into six layers equidistantly spaced along the apical-basal axis. We then further divided each layer into three positions equidistantly spaced from midrib to leaf margin, resulting in a total of 18 sampling locations. In addition, for 60 leaves, we sampled three positions from midrib to margin within only the widest layer of the leaf. Stomatal density and mean nearest neighbour distance (MNND) were calculated for each section. A replicated spatial point pattern approach quantified stomatal spatial relationships at different distances (0-300 μm). KEY RESULTS A tendency towards regular arrangement (inhibition as opposed to attraction or clustering) was observed between stomatal centres at distances <100 μm. Leaf layer (leaf length dimension) had no significant effect on local stomatal density, MNND or the spatial distribution characteristics of stomatal centres. In addition, we did not find greater inhibition at the centre of areoles, and in positions farther from the midrib. CONCLUSIONS Spatial inhibition might be caused by the one-cell-spacing rule, resulting in more regular arrangement of stomata, and it was found to exist at distances up to ~100 μm. This work implies that leaf hydraulic architecture, consisting of both vascular and mesophyll properties, is sufficient to prevent important spatial variability in water supply at the areole level.
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Affiliation(s)
- Peijian Shi
- College of Biology and the Environment, Bamboo Research Institute, Nanjing Forestry University, Nanjing, China
| | - Yabing Jiao
- College of Biology and the Environment, Bamboo Research Institute, Nanjing Forestry University, Nanjing, China
| | - Peter J Diggle
- Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Rolf Turner
- Department of Statistics, The University of Auckland, New Zealand
| | - Rong Wang
- College of Biology and the Environment, Bamboo Research Institute, Nanjing Forestry University, Nanjing, China
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
- Estonian Academy of Sciences, Tallinn, Estonia
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27
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Freeze tolerance influenced forest cover and hydrology during the Pennsylvanian. Proc Natl Acad Sci U S A 2021; 118:2025227118. [PMID: 34635589 DOI: 10.1073/pnas.2025227118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
The distribution of forest cover alters Earth surface mass and energy exchange and is controlled by physiology, which determines plant environmental limits. Ancient plant physiology, therefore, likely affected vegetation-climate feedbacks. We combine climate modeling and ecosystem-process modeling to simulate arboreal vegetation in the late Paleozoic ice age. Using GENESIS V3 global climate model simulations, varying pCO2, pO2, and ice extent for the Pennsylvanian, and fossil-derived leaf C:N, maximum stomatal conductance, and specific conductivity for several major Carboniferous plant groups, we simulated global ecosystem processes at a 2° resolution with Paleo-BGC. Based on leaf water constraints, Pangaea could have supported widespread arboreal plant growth and forest cover. However, these models do not account for the impacts of freezing on plants. According to our interpretation, freezing would have affected plants in 59% of unglaciated land during peak glacial periods and 73% during interglacials, when more high-latitude land was unglaciated. Comparing forest cover, minimum temperatures, and paleo-locations of Pennsylvanian-aged plant fossils from the Paleobiology Database supports restriction of forest extent due to freezing. Many genera were limited to unglaciated land where temperatures remained above -4 °C. Freeze-intolerance of Pennsylvanian arboreal vegetation had the potential to alter surface runoff, silicate weathering, CO2 levels, and climate forcing. As a bounding case, we assume total plant mortality at -4 °C and estimate that contracting forest cover increased net global surface runoff by up to 6.1%. Repeated freezing likely influenced freeze- and drought-tolerance evolution in lineages like the coniferophytes, which became increasingly dominant in the Permian and early Mesozoic.
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28
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Du B, Zhu Y, Kang H, Liu C. Spatial variations in stomatal traits and their coordination with leaf traits in Quercus variabilis across Eastern Asia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147757. [PMID: 34058578 DOI: 10.1016/j.scitotenv.2021.147757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 05/26/2023]
Abstract
The stomatal traits influence ecosystem carbon-water fluxes and play essential roles that enable plants to adapt to changing environmental conditions. However, how stomatal traits vary along a large climate gradient and whether stomatal traits coordinated with other leaf functional traits in response to environmental changes remain unclear. We investigated the stomatal density (SD), stomatal size (SS), and leaf traits (leaf area (LA), leaf mass per area (LMA), and vein density (VD)) of 44 in situ Quercus variabilis populations across Eastern Asia (24 to 51.8°N, 99 to 137°E) and 15 populations grown in a common garden, and evaluated their relationships with environmental factors. Stepwise multiple regression showed that the SD was significantly associated with mean annual precipitation (MAP), LMA, and VD, and the SS with latitude, mean annual temperature (MAT), mean monthly solar radiation (MMSR), and VD. The SD was positively correlated with the LMA, while the SS was negatively correlated with the VD. The SD and LMA increased with decreasing precipitation, which indicated that they may coordinate to commonly enhance plant resistance against drought. The SS decreased; however, the VD increased with temperature. This implied that plants might further reduce their SS by increasing VD limitations under global warming. In the common garden, plants exhibited a higher SD and VD and lower SS and LA compared to those in the field; however, no relation between the stomatal and leaf traits was observed. Our results suggested that stomatal traits have high environmental plasticity and are highly coordinated with other leaf functional traits in response to environmental changes. Nevertheless, this coordination may have been formed through long-term adaptations, rather than over short time spans.
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Affiliation(s)
- Baoming Du
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yanhua Zhu
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hongzhang Kang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Design, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Chunjiang Liu
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Urban Forest Ecosystem Research Station, State Forestry Administration, Shanghai 200240, China; Shanghai Yangtze River Delta Eco-environmental Change and Management Observation and Research Station, Ministry of Science and Technology, Shanghai 200240, China.
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29
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Zhao C, Chavan S, He X, Zhou M, Cazzonelli CI, Chen ZH, Tissue DT, Ghannoum O. Smart glass impacts stomatal sensitivity of greenhouse Capsicum through altered light. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3235-3248. [PMID: 33484266 DOI: 10.1093/jxb/erab028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Optical films that alter light transmittance may reduce energy consumption in high-tech greenhouses, but their impact on crop physiology remains unclear. We compared the stomatal responses of Capsicum plants grown hydroponically under control glass (70% diffuse light) or the smart glass (SG) film ULR-80, which blocked >50% of short-wave radiation and ~9% of photosynthetically active radiation (PAR). SG had no significant effects on steady-state (gs) or maximal (gmax) stomatal conductance. In contrast, SG reduced stomatal pore size and sensitivity to exogenous abscisic acid (ABA), thereby increasing rates of leaf water loss, guard cell K+ and Cl- efflux, and Ca2+ influx. SG induced faster stomatal closing and opening rates on transition between low (100 µmol m-2 s-1) and high PAR (1500 µmol m-2 s-1), which compromised water use efficiency relative to control plants. The fraction of blue light (0% or 10%) did not affect gs in either treatment. Increased expression of stomatal closure and photoreceptor genes in epidermal peels of SG plants is consistent with fast stomatal responses to light changes. In conclusion, stomatal responses of Capsicum to SG were more affected by changes in light intensity than spectral quality, and re-engineering of the SG should maximize PAR transmission, and hence CO2 assimilation.
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Affiliation(s)
- Chenchen Zhao
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- School of Science, Western Sydney University, Penrith, NSW 2753, Australia
- Tasmanian Institute of Agriculture, University of Tasmania, Prospect, TAS, 7250, Australia
| | - Sachin Chavan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
| | - Xin He
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
| | - Meixue Zhou
- Tasmanian Institute of Agriculture, University of Tasmania, Prospect, TAS, 7250, Australia
| | - Christopher I Cazzonelli
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
| | - Zhong-Hua Chen
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- School of Science, Western Sydney University, Penrith, NSW 2753, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
| | - Oula Ghannoum
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- National Vegetable Protected Cropping Centre, Western Sydney University, Hawkesbury Campus, Richmond, NSW 2753, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australia
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Fracasso A, Vallino M, Staropoli A, Vinale F, Amaducci S, Carra A. Increased water use efficiency in miR396-downregulated tomato plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 303:110729. [PMID: 33487336 DOI: 10.1016/j.plantsci.2020.110729] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 06/12/2023]
Abstract
MicroRNAs regulate plant development and responses to biotic and abiotic stresses but their impact on water use efficiency (WUE) is poorly known. Increasing WUE is a major task in crop improvement programs aimed to meet the challenges posed by the reduction in water availability associated with the ongoing climatic change. We have examined the physiological and molecular response to water stress of tomato (Solanum lycopersicum L.) plants downregulated for miR396 by target mimicry. In water stress conditions, miR396-downregulated plants displayed reduced transpiration and a less then proportional decrease in the photosynthetic rate that resulted in higher WUE. The increase in WUE was associated with faster foliar accumulation of abscisic acid (ABA), with the induction of several drought-protective genes and with the activation of the jasmonic acid (JA) and γ-aminobutyric acid (GABA) pathways. We propose a model in which the downregulation of miR396 leads to the activation of a complex molecular response to water stress. This response acts synergistically with a set of leaf morphological modifications to increase stomatal closure and preserve the efficiency of the photosynthetic activity, ultimately resulting in higher WUE.
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Affiliation(s)
- Alessandra Fracasso
- Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy
| | - Marta Vallino
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), 10135 Torino, Italy
| | - Alessia Staropoli
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), 80055 Portici, Italy
| | - Francesco Vinale
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), 80055 Portici, Italy; Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Naples, 80137, Italy
| | - Stefano Amaducci
- Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy
| | - Andrea Carra
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), 10135 Torino, Italy.
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Haworth M, Marino G, Loreto F, Centritto M. Integrating stomatal physiology and morphology: evolution of stomatal control and development of future crops. Oecologia 2021; 197:867-883. [PMID: 33515295 PMCID: PMC8591009 DOI: 10.1007/s00442-021-04857-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 01/11/2021] [Indexed: 11/29/2022]
Abstract
Stomata are central players in the hydrological and carbon cycles, regulating the uptake of carbon dioxide (CO2) for photosynthesis and transpirative loss of water (H2O) between plants and the atmosphere. The necessity to balance water-loss and CO2-uptake has played a key role in the evolution of plants, and is increasingly important in a hotter and drier world. The conductance of CO2 and water vapour across the leaf surface is determined by epidermal and stomatal morphology (the number, size, and spacing of stomatal pores) and stomatal physiology (the regulation of stomatal pore aperture in response to environmental conditions). The proportion of the epidermis allocated to stomata and the evolution of amphistomaty are linked to the physiological function of stomata. Moreover, the relationship between stomatal density and [CO2] is mediated by physiological stomatal behaviour; species with less responsive stomata to light and [CO2] are most likely to adjust stomatal initiation. These differences in the sensitivity of the stomatal density—[CO2] relationship between species influence the efficacy of the ‘stomatal method’ that is widely used to infer the palaeo-atmospheric [CO2] in which fossil leaves developed. Many studies have investigated stomatal physiology or morphology in isolation, which may result in the loss of the ‘overall picture’ as these traits operate in a coordinated manner to produce distinct mechanisms for stomatal control. Consideration of the interaction between stomatal morphology and physiology is critical to our understanding of plant evolutionary history, plant responses to on-going climate change and the production of more efficient and climate-resilient food and bio-fuel crops.
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Affiliation(s)
- Matthew Haworth
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy.
| | - Giovanni Marino
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
| | - Francesco Loreto
- Department of Biology, Agriculture and Food Sciences (CNR-DiSBA), National Research Council of Italy, Rome, Italy
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Mauro Centritto
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
- ENI-CNR Water Research Center "Hypatia of Alexandria", Research Center Metapontum Agrobios, Metaponto, Italy
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32
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Olson ME. The comparative method is not macroevolution: across-species evidence for within-species process. Syst Biol 2021; 70:1272-1281. [PMID: 33410880 DOI: 10.1093/sysbio/syaa086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 10/28/2020] [Accepted: 11/03/2020] [Indexed: 11/14/2022] Open
Abstract
It is common for studies that employ the comparative method for the study of adaptation, i.e. documentation of potentially adaptive across-species patterns of trait-environment or trait-trait correlation, to be designated as "macroevolutionary." Authors are justified in using "macroevolution" in this way by appeal to definitions such as "evolution above the species level." I argue that regarding the comparative method as "macroevolutionary" is harmful because it hides in serious ways the true causal content of hypotheses tested with the comparative method. The comparative method is a means of testing hypotheses of adaptation and their alternatives. Adaptation is a population level phenomenon, involving heritable interindividual variation that is associated with fitness differences. For example, given heritable intrapopulational variation, more streamlined individuals in populations of fast-moving aquatic animals have higher locomotory efficiency and thus better survivorship and more resources directed to reproduction than less streamlined ones. Direct evidence consistent with this population-level scenario includes the observation that many unrelated species of fast-moving aquatic animals have similar streamlined shapes, an example of the comparative method. Crucial to note in this example is that although the data are observed across species, the comparative method for studying adaptation tests hypotheses regarding standard population-level natural selection with no content that can be construed as "macro." Even less "macro," individual-level developmental dynamics can limit or bias the range of variants available for selection. Calling any of these studies "macroevolutionary" implies that some additional process is at work, shrouding the need to test adaptation hypotheses and study the range of variants that can be produced in development.
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Affiliation(s)
- Mark E Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito sn de Ciudad Universitaria, Ciudad de México, Mexico
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33
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Westbrook AS, McAdam SAM. Stomatal density and mechanics are critical for high productivity: insights from amphibious ferns. THE NEW PHYTOLOGIST 2021; 229:877-889. [PMID: 32761918 DOI: 10.1111/nph.16850] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
Angiosperm dominance in terrestrial landscapes is partially attributable to high photosynthetic capacities. Angiosperms benefit from diverse anatomical and physiological adaptations, making it difficult to determine which factors may have been prerequisites for the evolution of enhanced photosynthetic rates in this group. We employed a novel approach to this problem: comparisons between angiosperms and Marsileaceae, a family of semi-aquatic ferns that are among the only land plants to match angiosperm photosynthetic rates. We found that Marsileaceae have very high stomatal densities and, like angiosperms but unlike all other ferns previously studied, exhibit wrong-way stomatal responses to excision. These results suggest that stomatal density and a little-studied angiosperm trait, the capacity for lateral displacement of guard cells into neighboring epidermal cells, are crucial for facilitating high rates of gas exchange. Our analysis also associates these adaptations in Marsileaceae with an increased risk of excessive water loss during drought. Our findings indicate that evolution in stomatal physiology was a prerequisite for high photosynthetic capacities in vascular plants and a key driver of the abrupt Cretaceous rise of the angiosperms.
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Affiliation(s)
- Anna S Westbrook
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Scott A M McAdam
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
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Xiong D, Flexas J. From one side to two sides: the effects of stomatal distribution on photosynthesis. THE NEW PHYTOLOGIST 2020; 228:1754-1766. [PMID: 32652573 DOI: 10.1111/nph.16801] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
The functions of stomata have been studied for a long time; however, a clear understanding of the influences of stomatal distribution on photosynthesis, especially the CO2 diffusion, is still unclear. Here, we investigated the stomatal morphology, distribution on leaf surfaces, vein traits and gas exchange parameters of 61 species, of which 29 were amphistomatous, spanning 32 families. Photosynthesis (A) was tightly coupled with operational stomatal conductance (gs ) and mesophyll conductance (gm ) regardless of whether phylogenetic relationships were accounted for. Although the enhancement of gs from ferns and gymnosperms to angiosperms could largely be explained by the increase in leaf vein density (VLA) and stomatal density (SD), the gs was decoupled from VLA and SD across angiosperm species. Instead, A in angiosperms was further influenced by the allocation of stomatal pores on leaf surfaces, which dramatically increased gs and gm . Moreover, the ratio of gs to anatomically based maximum gs was, on average, 0.12 across species. Our results show that the shift of stomatal pores from one leaf side to both sides played an important role in regulating CO2 diffusion via both stomata and mesophyll tissues. Modifications of stomata distribution have potential as a functional trait for photosynthesis improvement.
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Affiliation(s)
- Dongliang Xiong
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jaume Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears/Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Carretera de Valldemossa Km 7.5, Palma de Mallorca, Illes Balears, 07121, Spain
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35
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Muir CD. A Stomatal Model of Anatomical Tradeoffs Between Gas Exchange and Pathogen Colonization. FRONTIERS IN PLANT SCIENCE 2020; 11:518991. [PMID: 33193466 PMCID: PMC7658178 DOI: 10.3389/fpls.2020.518991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Stomatal pores control leaf gas exchange and are one route for infection of internal plant tissues by many foliar pathogens, setting up the potential for tradeoffs between photosynthesis and pathogen colonization. Anatomical shifts to lower stomatal density and/or size may also limit pathogen colonization, but such developmental changes could permanently reduce the gas exchange capacity for the life of the leaf. I developed and analyzed a spatially explicit model of pathogen colonization on the leaf as a function of stomatal size and density, anatomical traits which partially determine maximum rates of gas exchange. The model predicts greater stomatal size or density increases the probability of colonization, but the effect is most pronounced when the fraction of leaf surface covered by stomata is low. I also derived scaling relationships between stomatal size and density that preserves a given probability of colonization. These scaling relationships set up a potential anatomical conflict between limiting pathogen colonization and minimizing the fraction of leaf surface covered by stomata. Although a connection between gas exchange and pathogen defense has been suggested empirically, this is the first mathematical model connecting gas exchange and pathogen defense via stomatal anatomy. A limitation of the model is that it does not include variation in innate immunity and stomatal closure in response to pathogens. Nevertheless, the model makes predictions that can be tested with experiments and may explain variation in stomatal size and density among plants. The model is generalizable to many types of pathogens, but lacks significant biological realism that may be needed for precise predictions.
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Matthaeus WJ, Schmidt J, White JD, Zechmann B. Novel perspectives on stomatal impressions: Rapid and non-invasive surface characterization of plant leaves by scanning electron microscopy. PLoS One 2020; 15:e0238589. [PMID: 32881951 PMCID: PMC7470294 DOI: 10.1371/journal.pone.0238589] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 08/19/2020] [Indexed: 11/18/2022] Open
Abstract
Scanning electron microscopy (SEM) is widely used to investigate the surface morphology, and physiological state of plant leaves. Conventionally used methods for sample preparation are invasive, irreversible, require skill and expensive equipment, and are time and labor consuming. This study demonstrates a method to obtain in vivo surface information of plant leaves by imaging replicas with SEM that is rapid and non-invasive. Dental putty was applied to the leaves for 5 minutes and then removed. Replicas were then imaged with SEM and compared to fresh leaves, and leaves that were processed conventionally by chemical fixation, dehydration and critical point drying. The surface structure of leaves was well preserved on the replicas. The outline of epidermal as well as guard cells could be clearly distinguished enabling determination of stomatal density. Comparison of the dimensions of guard cells revealed that replicas did not differ from fresh leaves, while conventional sample preparation induced strong shrinkage (-40% in length and -38% in width) of the cells when compared to guard cells on fresh leaves. Tilting the replicas enabled clear measurement of stomatal aperture dimensions. Summing up, the major advantages of this method are that it is inexpensive, non-toxic, simple to apply, can be performed in the field, and that results on stomatal density and in vivo stomatal dimensions in 3D can be obtained in a few minutes.
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Affiliation(s)
| | - Jonathan Schmidt
- Department of Biology, Baylor University, Waco, Texas, United States of America
| | - Joseph D. White
- Department of Biology, Baylor University, Waco, Texas, United States of America
| | - Bernd Zechmann
- Center for Microscopy and Imaging, Baylor University, Waco, Texas, United States of America
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37
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Wen Y, Zhao WL, Cao KF. Global convergence in the balance between leaf water supply and demand across vascular land plants. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:904-911. [PMID: 32635988 DOI: 10.1071/fp19101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
Coordination between the density of veins (water supply) and stomata (demand for water) has been found in the leaves of modern angiosperms and also in ferns. This suggests that this coordinated development is not a unique adaptation of derived angiosperms that enables their high productivity. To test this, we compiled leaf vein and stomatal density data from 520 land vascular plant species including derived angiosperms, basal angiosperms, gymnosperms and ferns. We found global coordination across vascular land plants, although the relationships were not significant in gymnosperms and vessel-less angiosperms. By comparing the evolution of xylem conduit elements with variation in the density of veins and stomata and theoretical stomatal conductance among plant lineages, we found that the physiological advantage of modern angiosperms is associated with the emergence of xylem with low intraconduit resistance and leaves with high vein and stomata densities. Thus our results indicate two major events associated with surges in xylem hydraulic capacity in angiosperms: (1) the origin of vessels and (2) the emergence of vessels with simple perforation plates, which diminished physical limitations on stomatal conductance. These evolutionary innovations may have enabled derived angiosperms to be more productive and adaptive to the changing climate.
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Affiliation(s)
- Yin Wen
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi 530004, China; and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi 530004, China
| | - Wan-Li Zhao
- Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta, Binzhou University, Binzhou, Shandong 256600, China; and Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi 530004, China; and Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi 530004, China; and Corresponding author.
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38
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Wilson JP, White JD, Montañez IP, DiMichele WA, McElwain JC, Poulsen CJ, Hren MT. Carboniferous plant physiology breaks the mold. THE NEW PHYTOLOGIST 2020; 227:667-679. [PMID: 32267976 DOI: 10.1111/nph.16460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/17/2019] [Indexed: 06/11/2023]
Abstract
How plants have shaped Earth surface feedbacks over geologic time is a key question in botanical and geological inquiry. Recent work has suggested that biomes during the Carboniferous Period contained plants with extraordinary physiological capacity to shape their environment, contradicting the previously dominant view that plants only began to actively moderate the Earth's surface with the rise of angiosperms during the Mesozoic Era. A recently published Viewpoint disputes this recent work, thus here, we document in detail, the mechanistic underpinnings of our modeling and illustrate the extraordinary ecophysiological nature of Carboniferous plants.
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Affiliation(s)
- Jonathan P Wilson
- Department of Environmental Studies, Haverford College, Haverford, PA, 19041, USA
| | - Joseph D White
- Department of Biology, Baylor University, Waco, TX, 76798, USA
| | - Isabel P Montañez
- Department of Earth and Planetary Sciences, University of California, Davis, CA, 95616, USA
| | - William A DiMichele
- Department of Paleobiology, Smithsonian Museum of Natural History, Washington, DC, 20560, USA
| | - Jennifer C McElwain
- Department of Botany, School of Natural Sciences, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Christopher J Poulsen
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Michael T Hren
- Center for Integrative Geosciences, University of Connecticut, Storrs, CT, 06269, USA
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Veselý P, Šmarda P, Bureš P, Stirton C, Muasya AM, Mucina L, Horová L, Veselá K, Šilerová A, Šmerda J, Knápek O. Environmental pressures on stomatal size may drive plant genome size evolution: evidence from a natural experiment with Cape geophytes. ANNALS OF BOTANY 2020; 126:323-330. [PMID: 32474609 PMCID: PMC7380457 DOI: 10.1093/aob/mcaa095] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/21/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS The idea that genome (size) evolution in eukaryotes could be driven by environmental factors is still vigorously debated. In extant plants, genome size correlates positively with stomatal size, leading to the idea that conditions enabling the existence of large stomata in fossil plants also supported growth of their genome size. We test this inductive assumption in drought-adapted, prostrate-leaved Cape (South Africa) geophytes where, compared with their upright-leaved geophytic ancestors, stomata develop in a favourably humid microclimate formed underneath their leaves. METHODS Stomatal parameters (leaf cuticle imprints) and genome size (flow cytometry) were measured in 16 closely related geophytic species pairs from seven plant families. In each pair, representing a different genus, we contrasted a prostrate-leaved species with its upright-leaved phylogenetic relative, the latter whose stomata are exposed to the ambient arid climate. KEY RESULTS Except for one, all prostrate-leaves species had larger stomata, and in 13 of 16 pairs they also had larger genomes than their upright-leaved relatives. Stomatal density and theoretical maximum conductance were less in prostrate-leaved species with small guard cells (<1 pL) but showed no systematic difference in species pairs with larger guard cells (>1 pL). Giant stomata were observed in the prostrate-leaved Satyrium bicorne (89-137 µm long), despite its relatively small genome (2C = 9 Gbp). CONCLUSIONS Our results imply that climate, through selection on stomatal size, might be able to drive genome size evolution in plants. The data support the idea that plants from 'greenhouse' geological periods with large stomata might have generally had larger genome sizes when compared with extant plants, though this might not have been solely due to higher atmospheric CO2 in these periods but could also have been due to humid conditions prevailing at fossil deposit sites.
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Affiliation(s)
- Pavel Veselý
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Petr Šmarda
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
- For correspondence. E-mail
| | - Petr Bureš
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Charles Stirton
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - A Muthama Muasya
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Ladislav Mucina
- Iluka Chair in Vegetation Science and Biogeography, Harry Butler Institute, Murdoch University, Murdoch, Perth, Australia
- Department of Geography and Environmental Studies, Stellenbosch University, Matieland, Stellenbosch, South Africa
| | - Lucie Horová
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Kristýna Veselá
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Alexandra Šilerová
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Jakub Šmerda
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
| | - Ondřej Knápek
- Department of Botany and Zoology, Masaryk University, Kotlářská, Brno, Czech Republic
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Zhu J, Yao J, Yu Q, He W, Xu C, Qin G, Zhu Q, Fan D, Zhu H. A Fast and Automatic Method for Leaf Vein Network Extraction and Vein Density Measurement Based on Object-Oriented Classification. FRONTIERS IN PLANT SCIENCE 2020; 11:499. [PMID: 32431721 PMCID: PMC7214732 DOI: 10.3389/fpls.2020.00499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 04/03/2020] [Indexed: 06/11/2023]
Abstract
Rapidly determining leaf vein network patterns and vein densities is biologically important and technically challenging. Current methods, however, are limited to vein contour extraction. Further image processing is difficult, and some leaf vein traits of interest therefore cannot be quantified. In this study, we proposed a novel method for the fast and accurate determination of leaf vein network patterns and vein density. Nine tree species with different leaf characteristics and vein types were applied to verify this method. To overcome the image processing difficulties at the microscopic scale, we adopted the remote object-oriented classification method applied comprehensively in the field of remote sensing research. The key to this approach is to determine the universally applicable leaf vein extraction threshold values (scale parameter, shape parameter, compactness parameter, brightness feature, spectral feature and geometric feature). Based on our analysis, the following recommended threshold values were determined: the scale parameter was 250, the shape parameter was 0.7, the compactness parameter was 0.3, the brightness feature value was 230∼280, the spectral feature value was 180∼230, and the geometric feature value was less than 2. With the optimal extraction parameters applied, the extraction precision was above 96.40% on average for the nine species studied. The leaf vein density calculation rate increased by more than 87.3% compared to that of the traditional methods. The results showed that this method is accurate, fast, flexible and complementary to existing technologies. It is an effective tool for the fast extraction of vein networks and the exploration of leaf vein characteristics, particularly for large-scale studies in plant vein physiology.
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Affiliation(s)
- Jiyou Zhu
- Key Laboratory for Silviculture and Conservation of Ministry of Education, Key Laboratory for Silviculture and Forest Ecosystem of State Forestry Administration, Research Center for Urban Forestry, Beijing Forestry University, Beijing, China
| | - Jiangming Yao
- Forestry College, Guangxi University, Nanning, China
| | - Qiang Yu
- Key Laboratory for Silviculture and Conservation of Ministry of Education, Key Laboratory for Silviculture and Forest Ecosystem of State Forestry Administration, Research Center for Urban Forestry, Beijing Forestry University, Beijing, China
| | - Weijun He
- Forestry College, Guangxi University, Nanning, China
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Chengyang Xu
- Key Laboratory for Silviculture and Conservation of Ministry of Education, Key Laboratory for Silviculture and Forest Ecosystem of State Forestry Administration, Research Center for Urban Forestry, Beijing Forestry University, Beijing, China
| | - Guoming Qin
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, China
| | - Qiuyu Zhu
- Inspection Department of Guangxi Medical College, Nanning, China
| | - Dayong Fan
- Key Laboratory for Silviculture and Conservation of Ministry of Education, Key Laboratory for Silviculture and Forest Ecosystem of State Forestry Administration, Research Center for Urban Forestry, Beijing Forestry University, Beijing, China
| | - Hua Zhu
- Inspection Department of Guangxi Medical College, Nanning, China
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Abstract
The control of gaseous exchange between the leaf and external atmosphere is governed by stomatal conductance (gs); therefore, stomata play a critical role in photosynthesis and transpiration and overall plant productivity. Stomatal conductance is determined by both anatomical features and behavioral characteristics. Here we review some of the osmoregulatory pathways in guard cell metabolism, genes and signals that determine stomatal function and patterning, and the recent work that explores coordination between gs and carbon assimilation (A) and the influence of spatial distribution of functional stomata on underlying mesophyll anatomy. We also evaluate the current literature on mesophyll-driven signals that may coordinate stomatal behavior with mesophyll carbon assimilation and explore stomatal kinetics as a possible target to improve A and water use efficiency. By understanding these processes, we can start to provide insight into manipulation of these regulatory pathways to improve stomatal behavior and identify novel unexploited targets for altering stomatal behavior and improving crop plant productivity.
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Affiliation(s)
- Tracy Lawson
- School of Life Science, University of Essex, Colchester CO4 3SQ, United Kingdom;
| | - Jack Matthews
- School of Life Science, University of Essex, Colchester CO4 3SQ, United Kingdom;
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Wang R, Chen H, Liu X, Wang Z, Wen J, Zhang S. Plant Phylogeny and Growth Form as Drivers of the Altitudinal Variation in Woody Leaf Vein Traits. FRONTIERS IN PLANT SCIENCE 2020; 10:1735. [PMID: 32117333 PMCID: PMC7012802 DOI: 10.3389/fpls.2019.01735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
Variation in leaf veins along environmental gradients reflects an important adaptive strategy of plants to the external habitats, because of their crucial roles in maintaining leaf water status and photosynthetic capacity. However, most studies concentrate on a few species and their vein variation across horizontal spatial scale, we know little about how vein traits shift along the vertical scale, e.g., elevational gradient along a mountain, and how such patterns are shaped by plant types and environmental factors. Here, we aimed to investigate the variation in leaf vein traits (i.e., vein density, VD; vein thickness, VT; and vein volume per unit leaf area, VV) of 93 woody species distributed along an elevational gradient (1,374-3,375 m) in a temperate mountain in China. Our results showed that altitude-related trends differed between growth forms. Tree plants from higher altitudes had lower VD but higher VT and VV than those from lower altitude; however, the opposite tend was observed in VD of shrubs, and no significant altitudinal changes in their VT or VV. Plant phylogenetic information at the clade level rather than climate explained most of variation in three leaf vein traits (17.1-86.6% vs. <0.011-6.3% explained variance), supporting the phylogenetic conservatism hypothesis for leaf vein traits. Moreover, the phylogenetic effects on vein traits differed between trees and shrubs, with the vein traits of trees being relatively more conserved. Together, our study provides new picture of leaf vein variation along the altitude, and highlights the importance of taking plant phylogeny into consideration when discussing trait variation from an ecological to a biogeographic scale.
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Affiliation(s)
- Ruili Wang
- College of Forestry, Northwest A&F University, Yangling, China
- Qinling National Forest Ecosystem Research Station, Huoditang, China
| | - Haoxuan Chen
- College of Forestry, Northwest A&F University, Yangling, China
| | - Xinrui Liu
- College of Forestry, Northwest A&F University, Yangling, China
| | - Zhibo Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China
| | - Jingwen Wen
- College of Forestry, Northwest A&F University, Yangling, China
| | - Shuoxin Zhang
- College of Forestry, Northwest A&F University, Yangling, China
- Qinling National Forest Ecosystem Research Station, Huoditang, China
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43
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Flexas J, Carriquí M. Photosynthesis and photosynthetic efficiencies along the terrestrial plant's phylogeny: lessons for improving crop photosynthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:964-978. [PMID: 31833133 DOI: 10.1111/tpj.14651] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 11/12/2019] [Accepted: 12/03/2019] [Indexed: 05/08/2023]
Abstract
Photosynthesis is the basis of all life on Earth. Surprisingly, until very recently, data on photosynthesis, photosynthetic efficiencies, and photosynthesis limitations in terrestrial land plants other than spermatophytes were very scarce. Here we provide an updated data compilation showing that maximum photosynthesis rates (expressed either on an area or dry mass basis) progressively scale along the land plant's phylogeny, from lowest values in bryophytes to largest in angiosperms. Unexpectedly, both photosynthetic water (WUE) and nitrogen (PNUE) use efficiencies also scale positively through the phylogeny, for which it has been commonly reported that these two efficiencies tend to trade-off between them when comparing different genotypes or a single species subject to different environmental conditions. After providing experimental evidence that these observed trends are mostly due to an increased mesophyll conductance to CO2 - associated with specific anatomical changes - along the phylogeny, we discuss how these findings on a large phylogenetic scale can provide useful information to address potential photosynthetic improvements in crops in the near future.
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Affiliation(s)
- Jaume Flexas
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears - Instituto de Investigaciones Agroambientales y de Economía del Agua (UIB-INAGEA), Carretera de Valldemossa Km 7.5, 07122, Palma, Spain
| | - Marc Carriquí
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears - Instituto de Investigaciones Agroambientales y de Economía del Agua (UIB-INAGEA), Carretera de Valldemossa Km 7.5, 07122, Palma, Spain
- School of Biological Sciences, University of Tasmania, Private Bag 51, 7001, Hobart, TAS, Australia
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44
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Kawai K, Okada N. Leaf vascular architecture in temperate dicotyledons: correlations and link to functional traits. PLANTA 2019; 251:17. [PMID: 31776668 DOI: 10.1007/s00425-019-03295-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Using 227 dicotyledonous species in temperate region, we found the relationships among densities of different-order veins, creating diversity of leaf vascular architectures. Dicotyledonous angiosperms commonly possess a hierarchical leaf vascular system, wherein veins of different orders have different functions. Minor vein spacing determines leaf hydraulic efficiency, whereas the major veins provide mechanical support. However, there is limited information on the coordination between these vein orders across species, limiting our understanding of how diversity in vein architecture is arrayed. We aimed to examine the (1) relationships between vein densities at two spatial scales (lower- vs. higher-order veins and among minor veins) and (2) relationships of vein densities with plant functional traits. We studied ten traits related to vein densities and three functional traits (leaf dry mass per area [LMA], leaf longevity [LL], and adult plant height [Hadult]) for 227 phylogenetically diverse plant species that occur in temperate regions and examined the vein-vein and vein-functional traits relationships across species. The densities of lower- and higher-order veins were positively correlated across species. The minor vein density was positively correlated with the densities of both areoles and free-ending veins, and vascular networks with higher minor vein density tended to have a lower ratio of free-ending veins to areoles across species. Neither densities of lower- nor higher-order veins were related to LMA and LL. On the other hand, the densities of veins and areoles tended to be positively correlated with Hadult. These results suggest that densities of different-order veins are developmentally coordinated across dicotyledonous angiosperms and form the independent axis in resource use strategies based on the leaf economics spectrum.
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Affiliation(s)
- Kiyosada Kawai
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto, 606-8502, Japan.
- Center for Ecological Research, Kyoto University, 509-3 Hirano 2-Chome, Otsu, Shiga, 520-2113, Japan.
| | - Naoki Okada
- Graduate School of Global Environmental Studies, Kyoto University, Yoshida-Honmachi, Skyo-Ku, 606-8501, Japan
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Thyroff EC, Burney OT, Mickelbart MV, Jacobs DF. Unraveling Shade Tolerance and Plasticity of Semi-Evergreen Oaks: Insights From Maritime Forest Live Oak Restoration. FRONTIERS IN PLANT SCIENCE 2019; 10:1526. [PMID: 31824542 PMCID: PMC6879670 DOI: 10.3389/fpls.2019.01526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
Quercus spp. (oaks) are generally intermediate in shade tolerance, yet there is large variation within the genus in shade tolerance and plasticity in response to varying resource availability. Ecophysiological knowledge specific to semi-evergreen Quercus spp. from subtropical maritime forests is lacking relative to temperate deciduous oaks. We studied the influence of light availability and plant competition on leaf physiology and performance of semi-evergreen Quercus virginiana on a barrier island along the US southern Atlantic coast. Seedlings were underplanted in pine (Pinus taeda) plantation stands with varying overstory density (clear-cut, heavy thin, light thin, and non-thinned; creating a gradient of understory light availability) and vegetation (no competition removal or herbaceous competition removal) treatments. After 2 years, seedling survival was higher with increasing light availability (clear-cut = heavy thin > light thin > non-thinned). Seedling growth (i.e., diameter, height, and crown width) increased similarly with increasing thinning intensity, while vegetation control was mainly beneficial to seedling growth in clear-cuts. These responses were partially explained by foliar nitrogen and leaf trait measurements, which followed the same pattern. Q. virginiana seedlings demonstrated high plasticity in their ability to acclimate to varying resource availability, as indicated by light response curves, specific leaf area, stomatal density, stomatal pore index, and maximum theoretical stomatal conductance. Light compensation and saturation points illustrated seedling capacity to increase net CO2 assimilation with increased light availability. Leaves on trees in the high light environment had the highest net CO2 assimilation, stomatal density, stomatal pore index, maximum theoretical stomatal conductance, and lowest specific leaf area. Although we demonstrated the relative shade tolerance of Q. virginiana in lower light environments (i.e., heavy and light thin plots), this semi-evergreen species shows high plasticity in capacity to respond to varying resource availability, similar to other Quercus spp. from mesic and Mediterranean environments.
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Affiliation(s)
- Emily C. Thyroff
- Department of Forestry and Natural Resources, Hardwood Tree Improvement and Regeneration Center, Purdue University, West Lafayette, IN, United States
| | - Owen T. Burney
- John T. Harrington Forestry Research Center, New Mexico State University, Las Cruces, NM, United States
| | - Michael V. Mickelbart
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Douglass F. Jacobs
- Department of Forestry and Natural Resources, Hardwood Tree Improvement and Regeneration Center, Purdue University, West Lafayette, IN, United States
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46
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Yiotis C, McElwain JC. A Novel Hypothesis for the Role of Photosynthetic Physiology in Shaping Macroevolutionary Patterns. PLANT PHYSIOLOGY 2019; 181:1148-1162. [PMID: 31484680 PMCID: PMC6836816 DOI: 10.1104/pp.19.00749] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/25/2019] [Indexed: 05/08/2023]
Abstract
The fossil record and models of atmospheric concentrations of O2 and CO2 suggest that past shifts in plant ecological dominance often coincided with dramatic changes in Earth's atmospheric composition. This study tested the effects of past changes in atmospheric composition on the photosynthetic physiology of a limited range of early-diverging angiosperms (eight), gymnosperms (three), and ferns (two). We performed physiological measurements on all species and used the results to parameterize simulations of their photosynthetic paleophysiology using three independent modeling approaches. Unique physiological attributes were identified for the three evolutionary groups: angiosperm taxa displayed significantly higher mesophyll conductance (g m), yet their stomatal conductance (g s) was lower than that of ferns. Gymnosperm taxa displayed low g s and g m, but they partially offset their significant diffusional limitations on photosynthesis through their higher maximum Rubisco carboxylation rate. Despite their high total conductance to CO2, fern taxa lacked an optimized control of g s, which was reflected in their low intrinsic water use efficiency. Simulations of the photosynthetic physiology of ferns, angiosperms, and gymnosperms through Earth's history demonstrated that past fluctuations in O2 and CO2 concentrations may have resulted in significant shifts in the relative competitiveness of the three evolutionary groups. Although preliminary because of limited species sampling, these findings hint at a potential mechanistic basis for the observed broad temporal correlation between atmospheric change and shifts in plant evolutionary group-level richness observed in the fossil record and are presented as a framework to be tested with paleophotosynthetic proxies and through increased species sampling.
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Affiliation(s)
- Charilaos Yiotis
- Botany Department, School of Natural Sciences, Trinity College, Dublin 2, Ireland
| | - Jennifer C McElwain
- Botany Department, School of Natural Sciences, Trinity College, Dublin 2, Ireland
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Holohan AD, Müller C, McElwain J. Heritable Changes in Physiological Gas Exchange Traits in Response to Long-Term, Moderate Free-Air Carbon Dioxide Enrichment. FRONTIERS IN PLANT SCIENCE 2019; 10:1210. [PMID: 31681354 PMCID: PMC6802601 DOI: 10.3389/fpls.2019.01210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Atmospheric carbon dioxide ([CO2]) concentrations significantly alter developmental plant traits with potentially far-reaching consequences for ecosystem function and productivity. However, contemporary evolutionary responses among extant plant species that coincide with modern, anthropogenically driven [CO2] rise have rarely been demonstrated among field-grown plant populations. Here we present findings from a long-term, free-air carbon dioxide enrichment (FACE) study in a seminatural European grassland ecosystem in which we observe a differential capacity among plant species to acclimate intrinsic water-use efficiencies (WUEs) in response to prolonged multigenerational exposure to elevated [CO2] concentrations. In a reciprocal swap trial, using controlled environment growth chambers, we germinated seeds from six of the most dominant plant species at the FACE site [Arrhenatherum elatius (L.), Trisetum flavescens (L.), Holcus lanatus (L.), Geranium pratense (L.), Sanguisorba officinalis (L.), and Plantago lanceolata (L.)]. We found that long-term exposure to elevated [CO2] strongly influenced the dynamic control of WUEi in the first filial generations (F1) of all species as well as an unequal ability to adapt to changes in the [CO2] of the growth environment among those species. Furthermore, despite trait-environment relationships of this nature often being considered evidence for local adaptation in plants, we demonstrate that the ability to increase WUEi does not necessarily translate to an ecological advantage in diverse species mixtures.
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Affiliation(s)
- Aidan David Holohan
- School of Biology and Environmental Science, The Earth Institute, O’Brien Centre for Science (E4.47), University College Dublin, Dublin, Ireland
| | - Christoph Müller
- School of Biology and Environmental Science, The Earth Institute, O’Brien Centre for Science (E4.47), University College Dublin, Dublin, Ireland
- Institute for Plant Ecology and Interdisciplinary Research Center (IFZ), Justus Liebig University, Giessen, Germany
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Jennifer McElwain
- Botany Department, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
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48
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Gago J, Carriquí M, Nadal M, Clemente-Moreno MJ, Coopman RE, Fernie AR, Flexas J. Photosynthesis Optimized across Land Plant Phylogeny. TRENDS IN PLANT SCIENCE 2019; 24:947-958. [PMID: 31362860 DOI: 10.1016/j.tplants.2019.07.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 07/02/2019] [Accepted: 07/04/2019] [Indexed: 05/08/2023]
Abstract
Until recently, few data were available on photosynthesis and its underlying mechanistically limiting factors in plants, other than crops and model species. Currently, a new large pool of data from extant representatives of basal terrestrial plant groups is emerging, allowing exploration of how photosynthetic capacity (Amax) increases from minimum values in bryophytes to maximum in tracheophytes, which is associated to an optimization of the balance between its limiting factors. From predominant mesophyll conductance limitation (lm) in bryophytes and lycophytes (fern allies) to stomatal conductance (ls) and lm colimitation in pteridophytes (ferns) and gymnosperms, a balanced colimitation by the three limitations is finally reached in angiosperms. We discuss the implications of this new knowledge for future biotechnological attempts to improve crop photosynthesis.
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Affiliation(s)
- Jorge Gago
- Research Group on Plant Biology under Mediterranean conditions, Departament de Biologia, Universitat de les Illes Balears / Institute of Agro-Environmental Research and Water Economy -INAGEA, Carretera de Valldemossa, 07122, Palma, Spain.
| | - Marc Carriquí
- Research Group on Plant Biology under Mediterranean conditions, Departament de Biologia, Universitat de les Illes Balears / Institute of Agro-Environmental Research and Water Economy -INAGEA, Carretera de Valldemossa, 07122, Palma, Spain
| | - Miquel Nadal
- Research Group on Plant Biology under Mediterranean conditions, Departament de Biologia, Universitat de les Illes Balears / Institute of Agro-Environmental Research and Water Economy -INAGEA, Carretera de Valldemossa, 07122, Palma, Spain
| | - María José Clemente-Moreno
- Research Group on Plant Biology under Mediterranean conditions, Departament de Biologia, Universitat de les Illes Balears / Institute of Agro-Environmental Research and Water Economy -INAGEA, Carretera de Valldemossa, 07122, Palma, Spain
| | - Rafael Eduardo Coopman
- Ecophysiology Laboratory for Forest Conservation, Instituto de Conservación, Biodiversidad y Territorio, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Campus Isla Teja, Casilla 567, Valdivia, Chile
| | - Alisdair Robert Fernie
- Central Metabolism Group, Molecular Physiology Department, Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Golm, Germany
| | - Jaume Flexas
- Research Group on Plant Biology under Mediterranean conditions, Departament de Biologia, Universitat de les Illes Balears / Institute of Agro-Environmental Research and Water Economy -INAGEA, Carretera de Valldemossa, 07122, Palma, Spain.
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49
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Gao J, Tian K. Stem and leaf traits as co-determinants of canopy water flux. PLANT DIVERSITY 2019; 41:258-265. [PMID: 31528785 PMCID: PMC6743011 DOI: 10.1016/j.pld.2019.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 05/26/2023]
Abstract
Transpiration through stomata in tree canopies plays an important role in terrestrial water cycles. However, the empirical relationship between leaf stomata anatomy and canopy stomatal conductance (G s) is surprisingly rare, thereby the underlying biological mechanisms of terrestrial water flux are not well elucidated. To gain further insight into these mechanisms, we reanalyzed the dataset of G s previously reported by Gao et al. (2015) using a quantile regression model. The results indicated that the reference G s (G sref, G s at 1 kPa) was negatively correlated with wood density at each quantile, which confirmed previous data; however, G sref was significantly correlated with stomatal density at the 0.6 quantile, i.e., 450 stomata mm-2. This highlighted the potential of using stomatal density as a trait to predict canopy water flux. A conceptual model of co-determinants of xylem and stomatal morphology suggests that these traits and their coordination may play a critical role in determining tree growth, physiological homeostatic response to environmental variables, water use efficiency, and drought resistance.
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Affiliation(s)
- Jianguo Gao
- Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, No.5 Yiheyuan Road Haidian District, Beijing, 100871, PR China
- Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, 200438, PR China
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Chinese Academy of Sciences, South China Botanical Garden, Guangzhou, 510650, PR China
| | - Kai Tian
- School of Life Sciences, Nanjing University, Nanjing, 210023, PR China
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50
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Henry C, John GP, Pan R, Bartlett MK, Fletcher LR, Scoffoni C, Sack L. A stomatal safety-efficiency trade-off constrains responses to leaf dehydration. Nat Commun 2019; 10:3398. [PMID: 31363097 PMCID: PMC6667445 DOI: 10.1038/s41467-019-11006-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/10/2019] [Indexed: 01/08/2023] Open
Abstract
Stomata, the microvalves on leaf surfaces, exert major influences across scales, from plant growth and productivity to global carbon and water cycling. Stomatal opening enables leaf photosynthesis, and plant growth and water use, whereas plant survival of drought depends on stomatal closure. Here we report that stomatal function is constrained by a safety-efficiency trade-off, such that species with greater stomatal conductance under high water availability (gmax) show greater sensitivity to closure during leaf dehydration, i.e., a higher leaf water potential at which stomatal conductance is reduced by 50% (Ψgs50). The gmax - Ψgs50 trade-off and its mechanistic basis is supported by experiments on leaves of California woody species, and in analyses of previous studies of the responses of diverse flowering plant species around the world. Linking the two fundamental key roles of stomata-the enabling of gas exchange, and the first defense against drought-this trade-off constrains the rates of water use and the drought sensitivity of leaves, with potential impacts on ecosystems.
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Affiliation(s)
- Christian Henry
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
| | - Grace P John
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- Department of Integrative Biology, University of Texas at Austin, 2415 Speedway, Austin, TX, 78712, USA
| | - Ruihua Pan
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- School of Ecology and Environment, Inner Mongolia University, 235 University West Road, 010021, Hohhot, Inner Mongolia, China
| | - Megan K Bartlett
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- Department of Viticulture and Enology, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Leila R Fletcher
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
| | - Christine Scoffoni
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA, 90032, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA.
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