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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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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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Frisk CA, Xistris-Songpanya G, Osborne M, Biswas Y, Melzer R, Yearsley JM. Phenotypic variation from waterlogging in multiple perennial ryegrass varieties under climate change conditions. FRONTIERS IN PLANT SCIENCE 2022; 13:954478. [PMID: 35991411 PMCID: PMC9387306 DOI: 10.3389/fpls.2022.954478] [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: 05/27/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Identifying how various components of climate change will influence ecosystems and vegetation subsistence will be fundamental to mitigate negative effects. Climate change-induced waterlogging is understudied in comparison to temperature and CO2. Grasslands are especially vulnerable through the connection with global food security, with perennial ryegrass dominating many flood-prone pasturelands in North-western Europe. We investigated the effect of long-term waterlogging on phenotypic responses of perennial ryegrass using four common varieties (one diploid and three tetraploid) grown in atmospherically controlled growth chambers during two months of peak growth. The climate treatments compare ambient climatological conditions in North-western Europe to the RCP8.5 climate change scenario in 2050 (+2°C and 550 ppm CO2). At the end of each month multiple phenotypic plant measurements were made, the plants were harvested and then allowed to grow back. Using image analysis and principal component analysis (PCA) methodologies, we assessed how multiple predictors (phenotypic, environmental, genotypic, and temporal) influenced overall plant performance, productivity and phenotypic responses. Long-term waterlogging was found to reduce leaf-color intensity, with younger plants having purple hues indicative of anthocyanins. Plant performance and yield was lower in waterlogged plants, with tetraploid varieties coping better than the diploid one. The climate change treatment was found to reduce color intensities further. Flooding was found to reduce plant productivity via reductions in color pigments and root proliferation. These effects will have negative consequences for global food security brought on by increased frequency of extreme weather events and flooding. Our imaging analysis approach to estimate effects of waterlogging can be incorporated into plant health diagnostics tools via remote sensing and drone-technology.
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Affiliation(s)
- Carl A. Frisk
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Earth Institute, University College Dublin, Dublin, Ireland
| | | | - Matthieu Osborne
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Yastika Biswas
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Rainer Melzer
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Earth Institute, University College Dublin, Dublin, Ireland
| | - Jon M. Yearsley
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Earth Institute, University College Dublin, Dublin, Ireland
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Israel WK, Watson-Lazowski A, Chen ZH, Ghannoum O. High intrinsic water use efficiency is underpinned by high stomatal aperture and guard cell potassium flux in C3 and C4 grasses grown at glacial CO2 and low light. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1546-1565. [PMID: 34718533 DOI: 10.1093/jxb/erab477] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/26/2021] [Indexed: 05/15/2023]
Abstract
We compared how stomatal morphology and physiology control intrinsic leaf water use efficiency (iWUE) in two C3 and six C4 grasses grown at ambient (400 µmol mol-1) or glacial CO2 (180 µmol mol-1) and high (1000 µmol m-2 s-1) or low light intensity (200 µmol m-2 s-1). C4 grasses tended to have higher iWUE and CO2 assimilation rates, and lower stomatal conductance (gs), operational stomatal aperture (aop), and guard cell K+ influx rate relative to C3 grasses, while stomatal size (SS) and stomatal density (SD) did not vary according to the photosynthetic type. Overall, iWUE and gs depended most on aop and density of open stomata. In turn, aop correlated with K+ influx, stomatal opening speed on transition to high light, and SS. Species with higher SD had smaller and faster-opening stomata. Although C4 grasses operated with lower gs and aop at ambient CO2, they showed a greater potential to open stomata relative to maximal stomatal conductance (gmax), indicating heightened stomatal sensitivity and control. We uncovered promising links between aop, gs, iWUE, and K+ influx among C4 grasses, and differential K+ influx responses of C4 guard cells to low light, revealing molecular targets for improving iWUE in C4 crops.
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Affiliation(s)
- Walter Krystler Israel
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australia
| | - Alexander Watson-Lazowski
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australia
| | - Zhong-Hua Chen
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Oula Ghannoum
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australia
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Carins Murphy MR, Jordan GJ, Brodribb TJ. Ferns are less dependent on passive dilution by cell expansion to coordinate leaf vein and stomatal spacing than angiosperms. PLoS One 2017; 12:e0185648. [PMID: 28953931 PMCID: PMC5617223 DOI: 10.1371/journal.pone.0185648] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 09/16/2017] [Indexed: 12/29/2022] Open
Abstract
Producing leaves with closely spaced veins is a key innovation linked to high rates of photosynthesis in angiosperms. A close geometric link between veins and stomata in angiosperms ensures that investment in enhanced venous water transport provides the strongest net carbon return to the plant. This link is underpinned by “passive dilution” via expansion of surrounding cells. However, it is not known whether this ‘passive dilution’ mechanism is present in plant lineages other than angiosperms and is another key feature of the angiosperms’ evolutionary success. Consequently, we sought to determine whether the ‘passive dilution’ mechanism is; (i) exclusive to the angiosperms, (ii) a conserved mechanism that evolved in the common ancestor of ferns and angiosperms, or (iii) has evolved continuously over time. To do this we first we assessed the plasticity of vein and stomatal density and epidermal cell size in ferns in response to light environment. We then compared the relationships between these traits found among ferns with modelled relationships that assume vein and stomatal density respond passively to epidermal cell expansion, and with those previously observed in angiosperms. Vein density, stomatal density and epidermal cell size were linked in ferns with remarkably similar relationships to those observed in angiosperms, except that fern leaves had fewer veins per stomata. However, plasticity was limited in ferns and stomatal spacing was dependent on active stomatal differentiation as well as passive cell expansion. Thus, ferns (like angiosperms) appear to coordinate vein and stomatal density with epidermal cell expansion to some extent to maintain a constant ratio between veins and stomata in the leaf. The different general relationships between vein density and stomatal density in ferns and angiosperms suggests the groups have different optimum balances between the production of vein tissue dedicated to water supply and stomatal tissue for gas exchange.
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Affiliation(s)
| | - Gregory J. Jordan
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Timothy J. Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
- * E-mail:
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