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Fradera-Soler M, Mravec J, Schulz A, Taboryski R, Jørgensen B, Grace OM. Revisiting an ecophysiological oddity: Hydathode-mediated foliar water uptake in Crassula species from southern Africa. PLANT, CELL & ENVIRONMENT 2024; 47:460-481. [PMID: 37876364 DOI: 10.1111/pce.14743] [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: 06/08/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
Hydathodes are usually associated with water exudation in plants. However, foliar water uptake (FWU) through the hydathodes has long been suspected in the leaf-succulent genus Crassula (Crassulaceae), a highly diverse group in southern Africa, and, to our knowledge, no empirical observations exist in the literature that unequivocally link FWU to hydathodes in this genus. FWU is expected to be particularly beneficial on the arid western side of southern Africa, where up to 50% of Crassula species occur and where periodically high air humidity leads to fog and/or dew formation. To investigate if hydathode-mediated FWU is operational in different Crassula species, we used the apoplastic fluorescent tracer Lucifer Yellow in combination with different imaging techniques. Our images of dye-treated leaves confirm that hydathode-mediated FWU does indeed occur in Crassula and that it might be widespread across the genus. Hydathodes in Crassula serve as moisture-harvesting structures, besides their more common purpose of guttation, an adaptation that has likely played an important role in the evolutionary history of the genus. Our observations suggest that ability for FWU is independent of geographical distribution and not restricted to arid environments under fog influence, as FWU is also operational in Crassula species from the rather humid eastern side of southern Africa. Our observations point towards no apparent link between FWU ability and overall leaf surface wettability in Crassula. Instead, the hierarchically sculptured leaf surfaces of several Crassula species may facilitate FWU due to hydrophilic leaf surface microdomains, even in seemingly hydrophobic species. Overall, these results confirm the ecophysiological relevance of hydathode-mediated FWU in Crassula and reassert the importance of atmospheric humidity for some arid-adapted plant groups.
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Affiliation(s)
- Marc Fradera-Soler
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- Royal Botanic Gardens, Kew, Richmond, Surrey, UK
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Plant Science and Biodiversity Center, Nitra, Slovakia
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Rafael Taboryski
- National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark, Lyngby, Denmark
| | - Bodil Jørgensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Olwen M Grace
- Royal Botanic Gardens, Kew, Richmond, Surrey, UK
- Royal Botanic Garden Edinburgh, Edinburgh, UK
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Beckett HAA, Webb D, Turner M, Sheppard A, Ball MC. Bark water uptake through lenticels increases stem hydration and contributes to stem swelling. PLANT, CELL & ENVIRONMENT 2024; 47:72-90. [PMID: 37811590 DOI: 10.1111/pce.14733] [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: 03/09/2023] [Accepted: 09/26/2023] [Indexed: 10/10/2023]
Abstract
Foliar water uptake can recharge water storage tissue and enable greater hydration than through access to soil water alone; however, few studies have explored the role of the bark in facilitating water uptake. We investigated pathways and dynamics of bark water uptake (BWU) in stems of the mangrove Avicennia marina. We provide novel evidence that specific entry points control dynamics of water uptake through the outer bark surface. Furthermore, using a fluorescent symplastic tracer dye we provide the first evidence that lenticels on the outer bark surface facilitate BWU, thus increasing stem water content by up to 3.7%. X-ray micro-computed tomography showed that BWU was sufficient to cause measurable swelling of stem tissue layers increasing whole stem cross-sectional area by 0.83 mm2 or 2.8%, implicating it as a contributor to the diel patterns of water storage recharge that buffer xylem water potential and maintain hydration of living tissue.
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Affiliation(s)
- Holly A A Beckett
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
| | - Daryl Webb
- Centre for Advanced Microscopy, Australian National University, Canberra, Australia
| | - Michael Turner
- Department of Applied Mathematics, Research School of Physics, Australian National University, Canberra, Australia
| | - Adrian Sheppard
- Department of Applied Mathematics, Research School of Physics, Australian National University, Canberra, Australia
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Canberra, Australia
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3
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Lima JF, Boanares D, Costa VE, Moreira ASFP. Do photosynthetic metabolism and habitat influence foliar water uptake in orchids? PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:257-267. [PMID: 36546714 DOI: 10.1111/plb.13499] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Epiphytic and rupicolous plants inhabit environments with limited water resources. Such plants commonly use Crassulacean Acid Metabolism (CAM), a photosynthetic pathway that accumulates organic acids in cell vacuoles at night, so reducing their leaf water potential and favouring water absorption. Foliar water uptake (FWU) aids plant survival during drought events in environments with high water deficits. We hypothesized that FWU represents a strategy employed by epiphytic and rupicolous orchids for water acquisition and that CAM will favour increased water absorption. We examined 6 epiphyte, 4 terrestrial and 6 rupicolous orchids that use C3 (n = 9) or CAM (n = 7) pathways. Five individuals per species were used to evaluate FWU, structural characteristics and leaf water balance. Rupicolous species with C3 metabolism had higher FWU than other species. FWU (Cmax and k) could be related to succulence, SLM and leaf RWC. The results indicated that high orchid leaf densities favoured FWU, as area available for water storage increases with leaf density. Structural characteristics linked to water storage (e.g. high RWC, succulence), on the other hand, could limit leaf water absorption by favouring high internal leaf water potentials. Epiphytic, rupicolous and terrestrial orchids showed FWU. Rupicolous species had high levels of FWU, probably through absorption from mist. However, succulence in plants with CAM appears to mitigate FWU.
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Affiliation(s)
- J F Lima
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - D Boanares
- Instituto Tecnológico Vale, Desenvolvimento Sustentável, Belém, Brazil
| | - V E Costa
- Instituto de Biociências, Centro de Isótopos Estáveis Prof. Dr. Carlos Ducatti, Botucatu, Brazil
| | - A S F P Moreira
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlândia, Brazil
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Kagawa A. Foliar water uptake as a source of hydrogen and oxygen in plant biomass. TREE PHYSIOLOGY 2022; 42:2153-2173. [PMID: 35554604 DOI: 10.1101/2020.08.20.260372] [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: 02/01/2022] [Accepted: 05/08/2022] [Indexed: 05/25/2023]
Abstract
Introductory biology lessons around the world typically teach that plants absorb water through their roots, but, unfortunately, absorption of water through leaves and subsequent transport and use of this water for biomass formation remains a field limited mostly to specialists. Recent studies have identified foliar water uptake as a significant net water source for terrestrial plants. The growing interest in the development of a new model that includes both foliar water uptake (in liquid form) and root water uptake to explain hydrogen and oxygen isotope ratios in leaf water and tree rings demands a method for distinguishing between these two water sources. Therefore, in this study, I have devised a new labelling method that utilizes two different water sources, one enriched in deuterium (HDO + D2O; δD = 7.0 × 10 4‰, δ18O = 4.1‰) and one enriched in oxygen-18 (H218O; δD = -85‰, δ18O = 1.1 × 104‰), to simultaneously label both foliar-absorbed and root-absorbed water and quantify their relative contributions to plant biomass. Using this new method, I here present evidence that, in the case of well-watered Cryptomeria japonica D. Don, hydrogen and oxygen incorporated into new leaf cellulose in the rainy season derives mostly from foliar-absorbed water (69% from foliar-absorbed water and 31% from root-absorbed water), while that of new root cellulose derives mostly from root-absorbed water (20% from foliar-absorbed water and 80% from root-absorbed water), and new branch xylem is somewhere in between (55% from foliar-absorbed water and 45% from root-absorbed water). The dual-labelling method first implemented in this study enables separate and simultaneous labelling of foliar-absorbed and root-absorbed water and offers a new tool to study the uptake, transport and assimilation processes of these waters in terrestrial plants.
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Affiliation(s)
- Akira Kagawa
- Forestry and Forest Products Research Institute, Wood Anatomy and Quality Laboratory, Tsukuba 305-8687, Japan
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Yan X, Chang Y, Zhao W, Qian C, Yin X, Fan X, Zhu X, Zhao X, Ma XF. Transcriptome profiling reveals that foliar water uptake occurs with C 3 and crassulacean acid metabolism facultative photosynthesis in Tamarix ramosissima under extreme drought. AOB PLANTS 2022; 14:plab060. [PMID: 35047161 PMCID: PMC8763614 DOI: 10.1093/aobpla/plab060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/14/2022] [Indexed: 05/21/2023]
Abstract
Tamarix ramosissima is a typical desert plant species that is widely distributed in the desert areas of Northwest China. It plays a significant role in sand fixation and soil water conservation. In particular, how it uses water to survive in the desert plays an important role in plant growth and ecosystem function. Previous studies have revealed that T. ramosissima can alleviate drought by absorbing water from its leaves under extreme drought conditions. To date, there is no clear molecular regulation mechanism to explain foliar water uptake (FWU). In the present study, we correlated diurnal meteorological data, sap flow and photosynthetic parameters to determine the physical and biological characteristics of FWU. Our results suggested that the lesser the groundwater, the easier it is for T. ramosissima to absorb water via the leaves. Gene ontology annotation and Kyoto Encyclopaedia of Genes and Genomes pathway analysis of the transcriptome profile of plants subjected to high humidity suggested that FWU was highly correlated to carbohydrate metabolism, energy transfer, pyruvate metabolism, hormone signal transduction and plant-pathogen interaction. Interestingly, as a C3 plant, genes such as PEPC, PPDK, MDH and RuBP, which are involved in crassulacean acid metabolism (CAM) photosynthesis, were highly upregulated and accompanied by FWU. Therefore, we proposed that in the case of sufficient water supply, C3 photosynthesis is used in T. ramosissima, whereas in cases of extreme drought, starch is degraded to provide CO2 for CAM photosynthesis to make full use of the water obtained via FWU and the water that was transported or stored to assimilating branches and stems. This study may provide not only an important theoretical foundation for FWU and conversion from C3 plants to CAM plants but also for engineering improved photosynthesis in high-yield drought-tolerant plants and mitigation of climate change-driven drought.
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Affiliation(s)
- Xia Yan
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
- Key Laboratory of Inland River Ecohydrology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
| | - Yan Chang
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
| | - Weijia Zhao
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
| | - Chaoju Qian
- Key Laboratory of Stress Physiology and Ecology in Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
| | - Xiaoyue Yin
- Key Laboratory of Stress Physiology and Ecology in Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingke Fan
- Key Laboratory of Stress Physiology and Ecology in Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinyu Zhu
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
| | - Xiangqiang Zhao
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
| | - Xiao-Fei Ma
- School of Life Sciences, Nantong University, Nantong 226019, Jiangsu, China
- Key Laboratory of Stress Physiology and Ecology in Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
- Corresponding author’s e-mail address:
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Bryant C, Fuenzalida TI, Zavafer A, Nguyen HT, Brothers N, Harris RJ, Beckett HAA, Holmlund HI, Binks O, Ball MC. Foliar water uptake via cork warts in mangroves of the Sonneratia genus. PLANT, CELL & ENVIRONMENT 2021; 44:2925-2937. [PMID: 34118083 DOI: 10.1111/pce.14129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
Foliar water uptake (FWU) occurs in plants of diverse ecosystems; however, the diversity of pathways and their associated FWU kinetics remain poorly resolved. We characterized a novel FWU pathway in two mangrove species of the Sonneratia genus, S. alba and S. caseolaris. Further, we assessed the influence of leaf wetting duration, wet-dry seasonality and leaf dehydration on leaf conductance to surface water (Ksurf ). The symplastic tracer dye, disodium fluorescein, revealed living cells subtending and encircling leaf epidermal structures known as cork warts as a pathway of FWU entry into the leaf. Rehydration kinetics experiments revealed a novel mode of FWU, with slow and steady rates of water uptake persistent over a duration of 12 hr. Ksurf increased with longer durations of leaf wetting and was greater in leaves with more negative water potentials at the initiation of leaf wetting. Ksurf declined by 68% between wet and dry seasons. Our results suggest that FWU via cork warts in Sonneratia sp. may be rate limited and under active regulation. We conclude that FWU pathways in halophytes may require ion exclusion to avoid uptake of salt when inundated, paralleling the capacity of halophyte roots for ion selectivity during water acquisition.
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Affiliation(s)
- Callum Bryant
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Tomas I Fuenzalida
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Alonso Zavafer
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Hoa T Nguyen
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
- Vietnam National University of Agriculture, Trau Quy, Gia Lam, Ha Noi, Vietnam
| | - Nigel Brothers
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Rosalie J Harris
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Holly A A Beckett
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Helen I Holmlund
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
- Pepperdine University, Natural Science Division, Malibu, CA, 90263, USA
| | - Oliver Binks
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
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Waseem M, Nie ZF, Yao GQ, Hasan M, Xiang Y, Fang XW. Dew absorption by leaf trichomes in Caragana korshinskii: An alternative water acquisition strategy for withstanding drought in arid environments. PHYSIOLOGIA PLANTARUM 2021; 172:528-539. [PMID: 33452683 DOI: 10.1111/ppl.13334] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 12/23/2020] [Accepted: 01/11/2021] [Indexed: 05/25/2023]
Abstract
Investigating plant morphological traits can provide insights into plant drought tolerance. To date, many papers have focused on plant hydraulic responses to drought during dehydration, but atmospheric water absorption by trichomes to mitigate drought stress by influencing leaf hydraulics in plant species that inhabit arid environments has been largely ignored. The experiment in this study was designed to assess how dew absorbed by leaf trichomes helps Caragana korshinskii withstand drought. The results showed that under a drought stress and dew (DS & D) treatment, C. korshinskii displayed a strong capacity to absorb dew with trichomes; exhibited slow decreases in leaf water potential (Ψleaf ), leaf hydraulic conductivity (Kleaf ), and gas exchange; experienced 50% Kleaf and gas exchange losses at lower relative soil water content levels than plants treated with drought stress and no dew (DS & ND); and experienced 50% Kleaf loss (Kleaf P50 ) at similar Ψleaf levels as DS & ND plants. Its congener C. sinica, which does not have leaf trichomes, displayed little ability to absorb dew under drought stress and did not show any remarkable improvement in the above parameters under the DS & D treatment. Our results indicated that leaf trichomes are important epidermal dew-uptake structures that assist in partially sustaining the leaf hydraulic assimilation system, mitigate the adverse effects of drought stress and contribute to the distribution of C. korshinskii in arid environments.
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Affiliation(s)
- Muhammad Waseem
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Zheng-Fei Nie
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Guang-Qian Yao
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Mahadi Hasan
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xiang-Wen Fang
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
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Li X, Zhang C, Zhang B, Wu D, Zhu D, Zhang W, Ye Q, Yan J, Fu J, Fang C, Ha D, Fu S. Nitrogen deposition and increased precipitation interact to affect fine root production and biomass in a temperate forest: Implications for carbon cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144497. [PMID: 33418324 DOI: 10.1016/j.scitotenv.2020.144497] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Fine roots connect belowground and aboveground systems and help regulate the carbon balance of terrestrial ecosystems by providing nutrients and water for plants. To evaluate the effects of atmospheric nitrogen (N) deposition and increased precipitation on fine root production and standing biomass in a temperate deciduous forest in central China, we conducted a 6-year experiment. From 2013 to 2018, we applied N (25 kg N ha-1 yr-1) and water (336 mm, 30% of the ambient annual precipitation) above the forest canopy, and we quantified fine root production and biomass in 2017 and 2018. At 0-10 cm soil depth, the statistical interaction between addition of N and water was not significant in terms of fine root production or biomass. At 0-10 cm soil depth, N addition significantly increased fine root production by 18.1%, but did not affect fine root biomass. Water addition significantly increased fine root production and biomass by 13.6 and 17.0%, respectively. Both N and water addition had significant direct positive effects on fine root production, and water addition had indirect positive effects on fine root biomass through decreasing soil NO3- concentration. At 10-30 cm soil depth, the statistical interaction between N addition and water addition was significant in terms of both fine root production and biomass, i.e., the positive effect of N addition was reduced by water addition, and vice versa. These findings indicate that fine roots and therefore belowground carbon storage may have complex responses to increases in atmospheric N deposition and changes in precipitation predicted for the future. The findings also suggest that results obtained from experiments that consider only one independent variable (e.g., N input or water input) and only one soil depth should be interpreted with caution.
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Affiliation(s)
- Xiaowei Li
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
| | - Chenlu Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China.
| | - Beibei Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Di Wu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Dandan Zhu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Wei Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Juemin Fu
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | | | - Denglong Ha
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | - Shenglei Fu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
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Foliar water uptake in arid ecosystems: seasonal variability and ecophysiological consequences. Oecologia 2020; 193:337-348. [PMID: 32474806 DOI: 10.1007/s00442-020-04673-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/19/2020] [Indexed: 10/24/2022]
Abstract
Foliar water uptake (FWU) has been reported for different species across several ecosystems types. However, little attention has been given to arid ecosystems, where FWU during dew formation or small rain events could ameliorate water deficits. FWU and their effects on leaf water potential (ΨLeaf) were evaluated in grasses and shrubs exploring different soil water sources in a Patagonian steppe. Also, seasonal variability in FWU and the role of cell wall elasticity in determining the effects on ΨLeaf were assessed. Eleven small rain events (< 8 mm) and 45 days with dew formation were recorded during the study period. All species exhibited FWU after experimental wetting. There was a large variability in FWU across species, from 0.04 mmol m-2 s-1 in species with deep roots to 0.75 mmol m-2 s-1 in species with shallow roots. Species-specific mean FWU rates were positively correlated with mean transpiration rates. The increase in ΨLeaf after leaf wetting varied between 0.65 MPa and 1.67 MPa across species and seasons. The effects of FWU on ΨLeaf were inversely correlated with cell wall elasticity. FWU integrated over both seasons varied between 28 mol m-2 in species with deep roots to 361 mol m-2 in species with shallow roots. Taking into account the percentage of coverage of each species, accumulated FWU represented 1.6% of the total annual transpiration of grasses and shrubs in this ecosystem. Despite this low FWU integrated over time compared to transpiration, wetting leaves surfaces can help to avoid larger water deficit during the dry season.
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10
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Binks O, Mencuccini M, Rowland L, da Costa ACL, de Carvalho CJR, Bittencourt P, Eller C, Teodoro GS, Carvalho EJM, Soza A, Ferreira L, Vasconcelos SS, Oliveira R, Meir P. Foliar water uptake in Amazonian trees: Evidence and consequences. GLOBAL CHANGE BIOLOGY 2019; 25:2678-2690. [PMID: 31012521 DOI: 10.1111/gcb.14666] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
The absorption of atmospheric water directly into leaves enables plants to alleviate the water stress caused by low soil moisture, hydraulic resistance in the xylem and the effect of gravity on the water column, while enabling plants to scavenge small inputs of water from leaf-wetting events. By increasing the availability of water, and supplying it from the top of the canopy (in a direction facilitated by gravity), foliar uptake (FU) may be a significant process in determining how forests interact with climate, and could alter our interpretation of current metrics for hydraulic stress and sensitivity. FU has not been reported for lowland tropical rainforests; we test whether FU occurs in six common Amazonian tree genera in lowland Amazônia, and make a first estimation of its contribution to canopy-atmosphere water exchange. We demonstrate that FU occurs in all six genera and that dew-derived water may therefore be used to "pay" for some morning transpiration in the dry season. Using meteorological and canopy wetness data, coupled with empirically derived estimates of leaf conductance to FU (kfu ), we estimate that the contribution by FU to annual transpiration at this site has a median value of 8.2% (103 mm/year) and an interquartile range of 3.4%-15.3%, with the biggest sources of uncertainty being kfu and the proportion of time the canopy is wet. Our results indicate that FU is likely to be a common strategy and may have significant implications for the Amazon carbon budget. The process of foliar water uptake may also have a profound impact on the drought tolerance of individual Amazonian trees and tree species, and on the cycling of water and carbon, regionally and globally.
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Affiliation(s)
- Oliver Binks
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | | | - Lucy Rowland
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Paulo Bittencourt
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Cleiton Eller
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Azul Soza
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | | | - Rafael Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Patrick Meir
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
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11
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Gong XW, Lü GH, He XM, Sarkar B, Yang XD. High Air Humidity Causes Atmospheric Water Absorption via Assimilating Branches in the Deep-Rooted Tree Haloxylon ammodendron in an Arid Desert Region of Northwest China. FRONTIERS IN PLANT SCIENCE 2019; 10:573. [PMID: 31156661 PMCID: PMC6530360 DOI: 10.3389/fpls.2019.00573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 04/16/2019] [Indexed: 05/30/2023]
Abstract
Atmospheric water is one of the main water resources for plants in arid ecosystems. However, whether deep-rooted, tomentum-less desert trees can absorb atmospheric water via aerial organs and transport the water into their bodies remains poorly understood. In the present study, a woody, deep-rooted, tomentum-less plant, Haloxylon ammodendron (C.A. Mey.) Bunge, was selected as the experimental object to investigate the preconditions for and consequences of foliar water uptake. Plant water status, gas exchange, and 18O isotopic signatures of the plant were investigated following a typical rainfall pulse and a high-humidity exposure experiment. The results showed that a high content of atmospheric water was the prerequisite for foliar water uptake by H. ammodendron in the arid desert region. After atmospheric water was absorbed via the assimilating branches, which perform the function of leaves due to leaf degeneration, the plant transported the water to the secondary branches and trunk stems, but not to the taproot xylem or the soil, based on the 18O isotopic signatures of the specimen. Foliar water uptake altered the plant water status and gas exchange-related traits, i.e., water potential, stomatal conductance, transpiration rate, and instantaneous water use efficiency. Our results suggest that atmospheric water might be a subsidiary water resource for sustaining the survival and growth of deep-rooted plants in arid desert regions. These findings contribute to the knowledge of plant water physiology and restoration of desert plants in the arid regions of the planet.
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Affiliation(s)
- Xue-Wei Gong
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
| | - Guang-Hui Lü
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
- Institute of Arid Ecology and Environment, Xinjiang University, Urumqi, China
| | - Xue-Min He
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
- Institute of Arid Ecology and Environment, Xinjiang University, Urumqi, China
| | - Binoy Sarkar
- Department of Animal and Plant Sciences, The University of Sheffield, Sheffield, United Kingdom
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
| | - Xiao-Dong Yang
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
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Yan X, Qian C, Yin X, Fan X, Zhao X, Gu M, Wang T, Ma XF. A whole-transcriptome approach to evaluate reference genes for quantitative diurnal gene expression studies under natural field conditions in Tamarix ramosissima leaves. ELECTRON J BIOTECHN 2018. [DOI: 10.1016/j.ejbt.2018.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Dawson TE, Goldsmith GR. The value of wet leaves. THE NEW PHYTOLOGIST 2018; 219:1156-1169. [PMID: 29959896 DOI: 10.1111/nph.15307] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/03/2018] [Indexed: 06/08/2023]
Abstract
Contents Summary 1156 I. Introduction 1156 II. How often are leaves wet? 1157 III. The costs of leaf wetting 1157 IV. The real and potential benefits of leaf wetting 1161 V. Wet leaves: costs, benefits and tradeoffs in a changing world 1165 Acknowledgements 1166 References 1166 SUMMARY: An often-overlooked feature of all plants is that their leaf surfaces are wet for significant periods over their lifetimes. Leaf wetting has a number of direct and indirect effects on plant function from the scale of the leaf to that of the ecosystem. The costs of leaf wetting for plant function, such as the growth of pathogens and the leaching of nutrients, have long been recognized. However, an emerging body of research has also begun to demonstrate some very clear benefits. For instance, leaf wetting can improve plant-water relations and lead to increased photosynthesis. Leaf wetting may also lead to synergistic effects on plant function, such as when leaf water potential improvements lead to enhanced growth that does not occur when plant leaves are dry. We identify important reasons why leaf wetting can be critical for plant sciences to not only acknowledge, but also directly address, in future research. To do so, we provide a framework for the consideration of the relative balance of the various costs and benefits resulting from leaf wetting, as well as how this balance may be expected to change given projected scenarios of global climate change in the future.
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Affiliation(s)
- Todd E Dawson
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy & Management, University of California, Berkeley, CA, 94720, USA
| | - Gregory R Goldsmith
- Ecosystem Fluxes Group, Laboratory for Atmospheric Chemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Schmid College of Science and Technology, Chapman University, Orange, CA, 92866, USA
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Li W, Qiang XJ, Han XR, Jiang LL, Zhang SH, Han J, He R, Cheng XG. Ectopic Expression of a Thellungiella salsuginea Aquaporin Gene, TsPIP1;1, Increased the Salt Tolerance of Rice. Int J Mol Sci 2018; 19:ijms19082229. [PMID: 30061546 PMCID: PMC6122036 DOI: 10.3390/ijms19082229] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 11/25/2022] Open
Abstract
Aquaporins play important regulatory roles in the transport of water and small molecules in plants. In this study, a Thellungiella salsuginea TsPIP1;1 aquaporin was transformed into Kitaake rice, and three transgenic lines were evaluated by profiling the changes of the physiological metabolism, osmotic potential, and differentially expressed genes under salt stress. The TsPIP1;1 protein contains six transmembrane domains and is localized in the cytoplasm membrane. Overexpression of the TsPIP1;1 gene not only increased the accumulation of prolines, soluble sugars and chlorophyll, but also lowered the osmotic potential and malondialdehyde content in rice under salt stress, and alleviated the amount of salt damage done to rice organs by regulating the distribution of Na/K ions, thereby promoting photosynthetic rates. Transcriptome sequencing confirmed that the differentially expressed genes that are up-regulated in rice positively respond to salt stimulus, the photosynthetic metabolic process, and the accumulation profiles of small molecules and Na/K ions. The co-expressed Rubisco and LHCA4 genes in rice were remarkably up-regulated under salt stress. This data suggests that overexpression of the TsPIP1;1 gene is involved in the regulation of water transport, the accumulation of Na/K ions, and the translocation of photosynthetic metabolites, thus conferring enhanced salt tolerance to rice.
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Affiliation(s)
- Wei Li
- Lab of Plant Nutrition Molecular Biology, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xiao-Jing Qiang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xiao-Ri Han
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
| | - Lin-Lin Jiang
- Lab of Plant Nutrition Molecular Biology, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Shu-Hui Zhang
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
| | - Jiao Han
- College of Life Science, Shanxi Normal University, Linfen 041004, China.
| | - Rui He
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
| | - Xian-Guo Cheng
- Lab of Plant Nutrition Molecular Biology, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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Secchi F, Pagliarani C, Zwieniecki MA. The functional role of xylem parenchyma cells and aquaporins during recovery from severe water stress. PLANT, CELL & ENVIRONMENT 2017; 40:858-871. [PMID: 27628165 DOI: 10.1111/pce.12831] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/09/2016] [Accepted: 08/27/2016] [Indexed: 05/05/2023]
Abstract
Xylem parenchyma cells [vessel associated cells (VACs)] constitute a significant fraction of the xylem in woody plants. These cells are often closely connected with xylem vessels or tracheids via simple pores (remnants of plasmodesmata fields). The close contact and biological activity of VACs during times of severe water stress and recovery from stress suggest that they are involved in the maintenance of xylem transport capacity and responsible for the restoration of vessel/tracheid functionality following embolism events. As recovery from embolism requires the transport of water across xylem parenchyma cell membranes, an understanding of stem-specific aquaporin expression patterns, localization and activity is a crucial part of any biological model dealing with embolism recovery processes in woody plants. In this review, we provide a short overview of xylem parenchyma cell biology with a special focus on aquaporins. In particular we address their distributions and activity during the development of drought stress, during the formation of embolism and the subsequent recovery from stress that may result in refilling. Complemented by the current biological model of parenchyma cell function during recovery from stress, this overview highlights recent breakthroughs on the unique ability of long-lived perennial plants to undergo cycles of embolism-recovery related to drought/rewetting or freeze/thaw events.
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Affiliation(s)
- Francesca Secchi
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, 10095, Italy
| | - Chiara Pagliarani
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Turin, Grugliasco, 10095, Italy
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