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Bicharanloo B, Bagheri Shirvan M, Cavagnaro TR, Keitel C, Dijkstra FA. Nitrogen addition and defoliation alter belowground carbon allocation with consequences for plant nitrogen uptake and soil organic carbon decomposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 846:157430. [PMID: 35863579 DOI: 10.1016/j.scitotenv.2022.157430] [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: 04/13/2022] [Revised: 06/29/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Grassland plants allocate photosynthetically fixed carbon (C) belowground to root biomass and rhizodeposition, but also to support arbuscular mycorrhizal fungi (AMF). These C allocation pathways could increase nutrient scavenging, but also mining of nutrients through enhanced organic matter decomposition. While important for grassland ecosystem functioning, methodological constraints have limited our ability to measure these processes under field conditions. We used 13CO2 and 15N pulse labelling methods to examine belowground C allocation to root biomass production, rhizodeposition and AMF colonisation during peak plant growth in a grassland field experiment after three years of N fertilisation (0 and 40 kg N ha-1 year-1) and defoliation frequency treatments ("low" and "high", with 3-4 and 6-8 simulated grazing events per year, mimicking moderate and intense grazing, respectively). Moreover, we quantified the consequences for plant nitrogen (N) uptake and decomposition of soil organic C (SOC). Nitrogen fertilisation increased rhizodeposition and AMF colonisation (by 63 % and 54 %), but reduced root biomass (by 25 %). With high defoliation frequency, AMF colonisation increased (by 60 %), but both root biomass and rhizodeposition declined (by 35 % and 58 %). Plant N uptake was highest without N fertilisation and low defoliation frequency, and positively related to root biomass and the number of root tips. Therefore, when N supply is low and the capacity to produce C through photosynthesis is high, belowground C allocation to root production and associated root tips was important to scavenge for N in the soil. In contrast, the strong positive relationship between the rate of rhizodeposition and SOC decomposition, suggests that rhizodeposition may help plants to mine for nutrients locked in SOC. Taken together, the results of this study suggest that belowground C allocation pathways affected by N fertilisation and defoliation frequency affect plant N scavenging and mining with important consequences for long-term grassland C dynamics.
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Affiliation(s)
- Bahareh Bicharanloo
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia.
| | - Milad Bagheri Shirvan
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
| | - Timothy R Cavagnaro
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Claudia Keitel
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
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Sun L, Ataka M, Han M, Han Y, Gan D, Xu T, Guo Y, Zhu B. Root exudation as a major competitive fine-root functional trait of 18 coexisting species in a subtropical forest. THE NEW PHYTOLOGIST 2021; 229:259-271. [PMID: 32772392 DOI: 10.1111/nph.16865] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Root exudation stimulates microbial decomposition and enhances nutrient availability to plants. It remains difficult to measure and predict this carbon flux in natural conditions, especially for mature woody plants. Based on a known conceptual framework of root functional traits coordination, we proposed that root functional traits may predict root exudation. We measured root exudation and other seven root morphological/chemical/physiological traits for 18 coexisting woody species in a deciduous-evergreen mixed forest in subtropical China. Root exudation, respiration, diameter and nitrogen (N) concentration all exhibited significant phylogenetic signals. We found that root exudation positively correlated with competitive traits (root respiration, N concentration) and negatively with a conservative trait (root tissue density). Furthermore, these relationships were independent of phylogenetic signals. A principal component analysis showed that root exudation and morphological traits loaded on two perpendicular axes. Root exudation is a competitive trait in a multidimensional fine-root functional coordination. The metabolic dimension on which root exudation loaded was relatively independent of the morphological dimension, indicating that increasing nutrient availability by root exudation might be a complementary strategy for plant nutrient acquisition. The positive relationship between root exudation and root respiration and N concentration is a promising approach for the future prediction of root exudation.
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Affiliation(s)
- Lijuan Sun
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Mioko Ataka
- Graduate School of Agriculture, Kyoto University, Kyoto, 6068502, Japan
| | - Mengguang Han
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Yunfeng Han
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Dayong Gan
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Tianle Xu
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Yanpei Guo
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Biao Zhu
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
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Wu E, Wang Y, Yahuza L, He M, Sun D, Huang Y, Liu Y, Yang L, Zhu W, Zhan J. Rapid adaptation of the Irish potato famine pathogen Phytophthora infestans to changing temperature. Evol Appl 2020; 13:768-780. [PMID: 32211066 PMCID: PMC7086108 DOI: 10.1111/eva.12899] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/19/2019] [Accepted: 10/28/2019] [Indexed: 01/06/2023] Open
Abstract
Temperature plays a multidimensional role in host-pathogen interactions. As an important element of climate change, elevated world temperature resulting from global warming presents new challenges to sustainable disease management. Knowledge of pathogen adaptation to global warming is needed to predict future disease epidemiology and formulate mitigating strategies. In this study, 21 Phytophthora infestans isolates originating from seven thermal environments were acclimated for 200 days under stepwise increase or decrease of experimental temperatures and evolutionary responses of the isolates to the thermal changes were evaluated. We found temperature acclimation significantly increased the fitness and genetic adaptation of P. infestans isolates at both low and high temperatures. Low-temperature acclimation enforced the countergradient adaptation of the pathogen to its past selection and enhanced the positive association between the pathogen's intrinsic growth rate and aggressiveness. At high temperatures, we found that pathogen growth collapsed near the maximum temperature for growth, suggesting a thermal niche boundary may exist in the evolutionary adaptation of P. infestans. These results indicate that pathogens can quickly adapt to temperature shifts in global warming. If this is associated with environmental conditions favoring pathogen spread, it will threaten future food security and human health and require the establishment of mitigating actions.
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Affiliation(s)
- E‐Jiao Wu
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
- Jiangsu Key Laboratory for Horticultural Crop Genetic ImprovementInstitute of PomologyJiangsu Academy of Agricultural SciencesNanjingChina
| | - Yan‐Ping Wang
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Lurwanu Yahuza
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Meng‐Han He
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
- College of Plant ProtectionHenan Agricultural UniversityZhengzhouChina
| | - Dan‐Li Sun
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yan‐Mei Huang
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yu‐Chan Liu
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Li‐Na Yang
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Wen Zhu
- Key Lab for Biopesticide and Chemical BiologyMinistry of EducationFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
| | - Jiasui Zhan
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFujian Agriculture and Forestry UniversityFuzhouChina
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural SciencesUppsalaSweden
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Slot M, Winter K. High tolerance of tropical sapling growth and gas exchange to moderate warming. Funct Ecol 2017. [DOI: 10.1111/1365-2435.13001] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Martijn Slot
- Smithsonian Tropical Research Institute Balboa, Ancón Republic of Panama
| | - Klaus Winter
- Smithsonian Tropical Research Institute Balboa, Ancón Republic of Panama
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Production of native arbuscular mycorrhizal fungi inoculum under different environmental conditions. Braz J Microbiol 2016; 48:87-94. [PMID: 27889421 PMCID: PMC5221349 DOI: 10.1016/j.bjm.2016.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/07/2016] [Indexed: 11/23/2022] Open
Abstract
In order to obtain an arbuscular mycorrhizal fungi (AMF) native inoculum from Sierra de Moa and determine the most appropriate conditions for its big scale production, four light and temperature combinations were tested in three plant species (Calophyllum antillanum, Talipariti elatum and Paspalum notatum). Growth and development parameters, as well as the mycorrhizal functioning of the seedlings were evaluated. The natural light treatment under high temperatures (L-H) was the most suitable for the growth and development of the three plant species, showing the highest total biomass values, mainly of root, and a positive root-shoot ratio balance. This treatment also promoted higher values of root mycorrhizal colonization, external mycelium and AMF spore density. A total of 38 AMF species were identified among the plants and environmental conditions tested. Archaeospora sp.1, Glomus sp.5, Glomus brohultii and G. glomerulatum were observed in all the treatments. The L-H condition can be recommended for native inoculum production, as it promotes a better expression of the AM symbiosis and an elevated production of mycorrhizal propagules.
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