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Sun T, Zhang X, Lv S, Lin X, Ma J, Liu J, Fang Q, Tang L, Liu L, Cao W, Liu B, Zhu Y. Improving the predictions of leaf photosynthesis during and after short-term heat stress with current rice models. Plant Cell Environ 2023; 46:3353-3370. [PMID: 37575035 DOI: 10.1111/pce.14683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/15/2023]
Abstract
In response to increasing global warming, extreme heat stress significantly alters photosynthetic production. While numerous studies have investigated the temperature effects on photosynthesis, factors like vapour pressure deficit (VPD), leaf nitrogen, and feedback of sink limitation during and after extreme heat stress remain underexplored. This study assessed photosynthesis calculations in seven rice growth models using observed maximum photosynthetic rate (Pmax ) during and after short-term extreme heat stress in multi-year environment-controlled experiments. Biochemical models (FvCB-type) outperformed light response curve-based models (LRC-type) when incorporating observed leaf nitrogen, photosynthetically active radiation, temperatures, and intercellular CO2 concentration (Ci ) as inputs. Prediction uncertainty during heat stress treatment primarily resulted from variation in temperatures and Ci . Improving FVPD (the slope for the linear effect of VPD on Ci /Ca ) to be temperature-dependent, rather than constant as in original models, significantly improved Ci prediction accuracy under heat stress. Leaf nitrogen response functions led to model variation in leaf photosynthesis predictions after heat stress, which was mitigated by calibrated nitrogen response functions based on active photosynthetic nitrogen. Additionally, accounting for observed differences in carbohydrate accumulation between panicles and stems during grain filling improved the feedback of sink limitation, reducing Ci overestimation under heat stress treatments.
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Affiliation(s)
- Ting Sun
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Key Laboratory of Specialty Agri-product Quality and Hazard Controlling Technology of Zhejiang Province, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, China
| | - Xiaohu Zhang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Suyu Lv
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xuanhao Lin
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jifeng Ma
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jiaming Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qizhao Fang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Liang Tang
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Leilei Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weixing Cao
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Bing Liu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yan Zhu
- National Engineering and Technology Center for Information Agriculture, Engineering Research Center of Smart Agriculture, Ministry of Education, Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for Modern Crop Production, College of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China
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2
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Waring EF, Perkowski EA, Smith NG. Soil nitrogen fertilization reduces relative leaf nitrogen allocation to photosynthesis. J Exp Bot 2023; 74:5166-5180. [PMID: 37235800 DOI: 10.1093/jxb/erad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 05/25/2023] [Indexed: 05/28/2023]
Abstract
The connection between soil nitrogen availability, leaf nitrogen, and photosynthetic capacity is not perfectly understood. Because these three components tend to be positively related over large spatial scales, some posit that soil nitrogen positively drives leaf nitrogen, which positively drives photosynthetic capacity. Alternatively, others posit that photosynthetic capacity is primarily driven by above-ground conditions. Here, we examined the physiological responses of a non-nitrogen-fixing plant (Gossypium hirsutum) and a nitrogen-fixing plant (Glycine max) in a fully factorial combination of light by soil nitrogen availability to help reconcile these competing hypotheses. Soil nitrogen stimulated leaf nitrogen in both species, but the relative proportion of leaf nitrogen used for photosynthetic processes was reduced under elevated soil nitrogen in all light availability treatments due to greater increases in leaf nitrogen content than chlorophyll and leaf biochemical process rates. Leaf nitrogen content and biochemical process rates in G. hirsutum were more responsive to changes in soil nitrogen than those in G. max, probably due to strong G. max investments in root nodulation under low soil nitrogen. Nonetheless, whole-plant growth was significantly enhanced by increased soil nitrogen in both species. Light availability consistently increased relative leaf nitrogen allocation to leaf photosynthesis and whole-plant growth, a pattern that was similar between species. These results suggest that the leaf nitrogen-photosynthesis relationship varies under different soil nitrogen levels and that these species preferentially allocated more nitrogen to plant growth and non-photosynthetic leaf processes, rather than photosynthesis, as soil nitrogen increased.
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Affiliation(s)
- Elizabeth F Waring
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
- Department of Natural Sciences, Northeastern State University, Tahlequah, OK, USA
| | - Evan A Perkowski
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Nicholas G Smith
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
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3
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Marro N, Lidoy J, Chico MÁ, Rial C, García J, Varela RM, Macías FA, Pozo MJ, Janoušková M, López-Ráez JA. Strigolactones: New players in the nitrogen-phosphorus signalling interplay. Plant Cell Environ 2022; 45:512-527. [PMID: 34719040 DOI: 10.1111/pce.14212] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 05/08/2023]
Abstract
Nitrogen (N) and phosphorus (P) are among the most important macronutrients for plant growth and development, and the most widely used as fertilizers. Understanding how plants sense and respond to N and P deficiency is essential to optimize and reduce the use of chemical fertilizers. Strigolactones (SLs) are phytohormones acting as modulators and sensors of plant responses to P deficiency. In the present work, we assess the potential role of SLs in N starvation and in the N-P signalling interplay. Physiological, transcriptional and metabolic responses were analysed in wild-type and SL-deficient tomato plants grown under different P and N regimes, and in plants treated with a short-term pulse of the synthetic SL analogue 2'-epi-GR24. The results evidence that plants prioritize N over P status by affecting SL biosynthesis. We also show that SLs modulate the expression of key regulatory genes of phosphate and nitrate signalling pathways, including the N-P integrators PHO2 and NIGT1/HHO. The results support a key role for SLs as sensors during early plant responses to both N and phosphate starvation and mediating the N-P signalling interplay, indicating that SLs are involved in more physiological processes than so far proposed.
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Affiliation(s)
- Nicolás Marro
- Department of Mycorrhizal Symbioses, Institute of Botany of the Czech Academy of Sciences, Průhonice, Czech Republic
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, FCEFyN, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Javier Lidoy
- Group of Mycorrhizas, Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - María Ángeles Chico
- Group of Mycorrhizas, Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - Carlos Rial
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (CeiA3), School of Science, University of Cádiz, Cádiz, Spain
| | - Juan García
- Group of Mycorrhizas, Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - Rosa M Varela
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (CeiA3), School of Science, University of Cádiz, Cádiz, Spain
| | - Francisco A Macías
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (CeiA3), School of Science, University of Cádiz, Cádiz, Spain
| | - María J Pozo
- Group of Mycorrhizas, Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - Martina Janoušková
- Department of Mycorrhizal Symbioses, Institute of Botany of the Czech Academy of Sciences, Průhonice, Czech Republic
| | - Juan A López-Ráez
- Group of Mycorrhizas, Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
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Young DY, Shachar-Hill Y. Large fluxes of fatty acids from membranes to triacylglycerol and back during N-deprivation and recovery in Chlamydomonas. Plant Physiol 2021; 185:796-814. [PMID: 33822218 PMCID: PMC8133548 DOI: 10.1093/plphys/kiaa071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Microalgae accumulate triacylglycerol (TAG) during nutrient deprivation and break it down after nutrient resupply, and these processes involve dramatic shifts in cellular carbon allocation. Due to the importance of algae in the global carbon cycle, and the potential of algal lipids as feedstock for chemical and fuel production, these processes are of both ecophysiological and biotechnological importance. However, the metabolism of TAG is not well understood, particularly the contributions of fatty acids (FAs) from different membrane lipids to TAG accumulation and the fate of TAG FAs during degradation. Here, we used isotopic labeling time course experiments on Chlamydomonas reinhardtii to track FA synthesis and transfer between lipid pools during nitrogen (N)-deprivation and resupply. When cells were labeled before N-deprivation, total levels of label in cellular FAs were unchanged during subsequent N-deprivation and later resupply, despite large fluxes into and out of TAG and membrane lipid pools. Detailed analyses of FA levels and labeling revealed that about one-third of acyl chains accumulating in TAG during N-deprivation derive from preexisting membrane lipids, and in total, at least 45% of TAG FAs passed through membrane lipids at one point. Notably, most acyl chains in membrane lipids during recovery after N-resupply come from TAG. Fluxes of polyunsaturated FAs from plastidic membranes into TAG during N-deprivation were particularly noteworthy. These findings demonstrate a high degree of integration of TAG and membrane lipid metabolism and highlight a role for TAG in storage and supply of membrane lipid components.
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Affiliation(s)
- Danielle Yvonne Young
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Yair Shachar-Hill
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
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5
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Sakakibara H. Cytokinin biosynthesis and transport for systemic nitrogen signaling. Plant J 2021; 105:421-430. [PMID: 33015901 DOI: 10.1111/tpj.15011] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
The plasticity of growth and development in response to environmental changes is one of the essential aspects of plant behavior. Cytokinins play an important role as signaling molecules in the long-distance communication between organs in systemic growth regulation in response to nitrogen. The spatial distribution of the expression sites of cytokinin biosynthesis genes leads to structural differences in the molecular species transported through the xylem and phloem, giving root-borne trans-hydroxylated cytokinins, namely trans-zeatin (tZ) type, a specialized efficacy in regulating shoot growth. Furthermore, root-to-shoot translocation via the xylem, tZ, and its precursor, the tZ riboside, controls different sets of shoot growth traits to fine-tune shoot growth in response to nitrogen availability. In addition to nitrogen, photosynthetically generated sugars positively regulate de novo cytokinin biosynthesis in the roots, and contribute to plant growth under elevated CO2 conditions. In shoot-to-root signaling, cytokinins also play a role in the regulation of nutrient acquisition and root system growth in cooperation with other types of signaling molecules, such as C-TERMINALLY ENCODED PEPTIDE DOWNSTREAMs. As cytokinin is a key regulator for the maintenance of shoot apical meristem, deepening our understanding of the regulatory mechanisms of cytokinin biosynthesis and transport in response to nitrogen is important not only for basic comprehension of plant growth, but also to ensure the stability of agricultural production.
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Affiliation(s)
- Hitoshi Sakakibara
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
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6
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Abstract
Nitrogen (N), as a macro-element, plays a vital role in plant growth and development. N deficiency affects plant productivity by decreasing photosynthesis, leaf area and longevity of green leaf. To date, many studies have reported that the relationship between photosynthesis and N supply. Here, we summarized the physiological response of photosynthesis to N deficiency in leaf structure and N allocation within the leaf. In serious N stress, photosynthetic rate decreases for almost all plants. The reasons as follows:(1) reducing stomatal conductance of mesophyll cell (gs) and bundle sheath cells (gbs) which influences intercellular CO2 concentration; (2) reducing the content of bioenergetics and light-harvesting protein which inhibits electron transport rate and increase the light energy dissipated as heat; (3) reducing the content and/or activity of photosynthetic enzymes which reduces carboxylation rate. During reproductive stage, N stress induces plant senescence and N components degradation, especially photosynthetic enzymes and thylakoid N, and thus reduces photosynthesis. To keep high grain yield in low N deficiency, we should choose the genotype with higher N allocation within bioenergetics and lower degradation of photosynthetic enzymes. This review provides a generalized N allocation in response to N stress and gives a new prospect for breeding N-efficient genotypes.
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Affiliation(s)
- Xiaohuan Mu
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, PR China.
| | - Yanling Chen
- College of Resources and Environment, Qingdao Agricultural University, Qingdao, Shandong, 266109, PR China.
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7
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Takeuchi T, Lin YT, Fekaris N, Umen J, Sears BB, Benning C. Modulation of CHT7 Complexes during Light/Dark- and Nitrogen-Mediated Life Cycle Transitions of Chlamydomonas. Plant Physiol 2020; 184:1762-1774. [PMID: 33004613 PMCID: PMC7723089 DOI: 10.1104/pp.20.00864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The Chlamydomonas reinhardtii Compromised Hydrolysis of Triacylglycerols7 (CHT7) protein has been previously implicated in the regulation of DNA metabolism and cell-cycle-related gene expression during nitrogen (N) deprivation, and its predicted protein interaction domains are necessary for function. Here, we examined impacts of the cht7 mutation during the cell division cycle under nutrient deficiency in light-dark synchronized cultures. We explored the potential mechanisms affecting CHT7 complex activities during the cell cycle and N starvation, with a focus on the possible interaction between CHT7 and the C. reinhardtii retinoblastoma tumor suppressor (RB) protein homolog MAT3. Notably, the absence of CHT7 did not negatively impact the synchrony of cell division and cell cycle progression during diel growth. Although the majority of CHT7 and MAT3/RB proteins were observed in separate complexes by blue native-PAGE, the two proteins coimmunoprecipitated both during synchronized growth and following N deprivation, suggesting the presence of low abundance subcomplexes containing CHT7 and MAT3/RB. Furthermore, we observed several phosphorylated isoforms of CHT7 under these conditions. To test the potential role of phosphorylation on the structure and function of CHT7, we performed site-directed mutagenesis of previously identified phosphorylated amino acids within CHT7. These phosphorylated residues were dispensable for CHT7 function, but phosphorylated variants of CHT7 persisted, indicating that yet-unidentified residues within CHT7 are also likely phosphorylated. Based on the interaction of CHT7 and MAT3/RB, we postulate the presence of a low-abundance or transient regulatory complex in C. reinhardtii that may be similar to DREAM-like complexes in other organisms.
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Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Yang-Tsung Lin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Nicholas Fekaris
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - James Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Barbara B Sears
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
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Wen B, Xiao W, Mu Q, Li D, Chen X, Wu H, Li L, Peng F. How does nitrate regulate plant senescence? Plant Physiol Biochem 2020; 157:60-69. [PMID: 33091797 DOI: 10.1016/j.plaphy.2020.08.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 05/19/2023]
Abstract
Nitrogen is an essential macronutrient for plant growth and development and plays an important role in the whole life process of plants. Nitrogen is an important component of amino acids, chlorophyll, plant hormones and secondary metabolites. Nitrogen deficiency leads to early senescence in plants, which is accompanied by changes in gene expression, metabolism, growth, development, and physiological and biochemical traits, which ensures efficient nitrogen recycling and enhances the plant's tolerance to low nitrogen. Therefore, it is very important to understand the adaptation mechanisms of plants under nitrogen deficiency for the efficient utilization of nitrogen and gene regulation. With the popularization of molecular biology, bioinformatics and transgenic technology, the metabolic pathways of nitrogen-deficient plants have been verified, and important progress has been made. However, how the responses of plants to nitrogen deficiency affect the biological processes of the plants is not well understood. The current research also cannot completely explain how the metabolic pathways identified show other reactions or phenotypes through interactions or cascades after nitrogen inhibition. Nitrate is the main form of nitrogen absorption. In this review, we discuss the role of nitrate in plant senescence. Understanding how nitrate inhibition affects nitrate absorption, transport, and assimilation; chlorophyll synthesis; photosynthesis; anthocyanin synthesis; and plant hormone synthesis is key to sustainable agriculture.
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Affiliation(s)
- Binbin Wen
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China
| | - Wei Xiao
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China
| | - Qin Mu
- College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Dongmei Li
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China
| | - Xiude Chen
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China
| | - Hongyu Wu
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China
| | - Ling Li
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China.
| | - Futian Peng
- College of Horticulture Science and Engineering, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China.
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Li YT, Li Y, Li YN, Liang Y, Sun Q, Li G, Liu P, Zhang ZS, Gao HY. Dynamic light caused less photosynthetic suppression, rather than more, under nitrogen deficit conditions than under sufficient nitrogen supply conditions in soybean. BMC Plant Biol 2020; 20:339. [PMID: 32680459 PMCID: PMC7368695 DOI: 10.1186/s12870-020-02516-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 06/23/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Plants are always exposed to dynamic light. The photosynthetic light use efficiency of leaves is lower in dynamic light than in uniform irradiance. Research on the influence of environmental factors on dynamic photosynthesis is very limited. Nitrogen is critical for plants, especially for photosynthesis. Low nitrogen (LN) decreases ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and thus limits photosynthesis. The decrease in Rubisco also delays photosynthetic induction in LN leaves; therefore, we hypothesized that the difference of photosynthetic CO2 fixation between uniform and dynamic light will be greater in LN leaves compared to leaves with sufficient nitrogen supply. RESULTS To test this hypothesis, soybean plants were grown under low or high nitrogen (HN), and the photosynthetic gas exchange, enzyme activity and protein amount in leaves were measured under uniform and dynamic light. Unexpectedly, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves. The underlying mechanism was also clarified. Short low-light (LL) intervals did not affect Rubisco activity but clearly deactivated fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase), indicating that photosynthetic induction after a LL interval depends on the reactivation of FBPase and SBPase rather than Rubisco. In LN leaves, the amount of Rubisco decreased more than FBPase and SBPase, so FBPase and SBPase were present in relative excess. A lower fraction of FBPase and SBPase needs to be activated in LN leaves for photosynthesis recovery during the high-light phase of dynamic light. Therefore, photosynthetic recovery is faster in LN leaves than in HN leaves, which relieves the photosynthetic suppression caused by dynamic light in LN leaves. CONCLUSIONS Contrary to our expectations, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves of soybean. This is the first report of a stress condition alleviating the photosynthetic suppression caused by dynamic light.
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Affiliation(s)
- Yu-Ting Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Yue-Nan Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Liang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Qiang Sun
- Tai'an Testing Center For Food And Drug Control, Tai'an, Shandong Province, China
| | - Geng Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Peng Liu
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Zi-Shan Zhang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Hui-Yuan Gao
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
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Srivastava AK, Shankar A, Nalini Chandran AK, Sharma M, Jung KH, Suprasanna P, Pandey GK. Emerging concepts of potassium homeostasis in plants. J Exp Bot 2020; 71:608-619. [PMID: 31624829 DOI: 10.1093/jxb/erz458] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
Potassium (K+) is an essential cation in all organisms that influences crop production and ecosystem stability. Although most soils are rich in K minerals, relatively little K+ is present in forms that are available to plants. Moreover, leaching and run-off from the upper soil layers contribute to K+ deficiencies in agricultural soils. Hence, the demand for K fertilizer is increasing worldwide. K+ regulates multiple processes in cells and organs, with K+ deficiency resulting in decreased plant growth and productivity. Here, we discuss the complexity of the reactive oxygen species-calcium-hormone signalling network that is responsible for the sensing of K+ deficiency in plants, together with genetic approaches using K+ transporters that have been used to increase K+ use efficiency (KUE) in plants, particularly under environmental stress conditions such as salinity and heavy metal contamination. Publicly available rice transcriptome data are used to demonstrate the two-way relationship between K+ and nitrogen nutrition, highlighting how each nutrient can regulate the uptake and root to shoot translocation of the other. Future research directions are discussed in terms of this relationship, as well as prospects for molecular approaches for the generation of improved varieties and the implementation of new agronomic practices. An increased knowledge of the systems that sense and take up K+, and their regulation, will not only improve current understanding of plant K+ homeostasis but also facilitate new research and the implementation of measures to improve plant KUE for sustainable food production.
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Affiliation(s)
- Ashish Kumar Srivastava
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
| | - Alka Shankar
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Anil Kumar Nalini Chandran
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin, Republic of Korea
| | - Manisha Sharma
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Ki-Hong Jung
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin, Republic of Korea
| | - Penna Suprasanna
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
| | - Girdhar K Pandey
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
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11
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Hoshika Y, De Carlo A, Baraldi R, Neri L, Carrari E, Agathokleous E, Zhang L, Fares S, Paoletti E. Ozone-induced impairment of night-time stomatal closure in O 3-sensitive poplar clone is affected by nitrogen but not by phosphorus enrichment. Sci Total Environ 2019; 692:713-722. [PMID: 31539979 DOI: 10.1016/j.scitotenv.2019.07.288] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Nocturnal transpiration may be a key factor influencing water use in plants. Tropospheric ozone (O3) and availability of nutrients such as nitrogen (N) and phosphorus (P) in the soil can affect daytime water use through stomata, but the combined effects of O3, N and P on night-time stomatal conductance (gs) are not known. We investigated the effects of O3 and soil availability of N and P on nocturnal gs and the dynamics of stomatal response after leaf severing in an O3-sensitive poplar clone (Oxford) subjected to combined treatments over a growing season in an O3 free air controlled exposure (FACE) facility. The treatments were two soil N levels (0 and 80 kg N ha-1; N0 and N80), three soil P levels (0, 40 and 80 kg P ha-1; P0, P40 and P80) and three O3 levels (ambient concentration, AA [35.0 ppb as hourly mean]; 1.5 × AA; 2.0 × AA). The analysis of stomatal dynamics after leaf severing suggested that O3 impaired stomatal closure execution. As a result, nocturnal gs was increased by 2.0 × AA O3 in August (+39%) and September (+108%). Night-time gs was correlated with POD0 (phytotoxic O3 dose) and increased exponentially after 40 mmol m-2 POD0. Such increase of nocturnal gs was attributed to the emission of ethylene due to 2.0 × AA O3 exposure, while foliar abscisic acid (ABA) or indole-3-acetic acid (IAA) did not affect gs at night. Interestingly, the O3-induced stomatal opening at night was limited by N treatments in August, but not limited in September. Phosphorus decreased nocturnal gs, although P did not modify the O3-induced stomatal dysfunction. The results suggest that the increased nocturnal gs may be associated with a need to improve N acquisition to cope with O3 stress.
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Affiliation(s)
- Yasutomo Hoshika
- Istituto di Ricerca sugli Ecosistemi Terrestri (IRET), National Research Council (CNR), Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy.
| | - Anna De Carlo
- Istituto di Bioeconomia (IBE), National Research Council (CNR), via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Rita Baraldi
- Istituto di Bioeconomia (IBE), National Research Council (CNR), Via P. Gobetti, 101, 40129 Bologna, Italy
| | - Luisa Neri
- Istituto di Bioeconomia (IBE), National Research Council (CNR), Via P. Gobetti, 101, 40129 Bologna, Italy
| | - Elisa Carrari
- Istituto di Ricerca sugli Ecosistemi Terrestri (IRET), National Research Council (CNR), Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy
| | - Evgenios Agathokleous
- Institute of Ecology, Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science and Technology (NUIST), Nanjing, Jiangsu 210044, China
| | - Lu Zhang
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Changjiang Road 600, 150030 Harbin, China
| | - Silvano Fares
- Research Centre for Forestry and Wood, Council for Agricultural Research and Economics, Roma, Italy
| | - Elena Paoletti
- Istituto di Ricerca sugli Ecosistemi Terrestri (IRET), National Research Council (CNR), Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy
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12
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Mei L, Yang X, Zhang S, Zhang T, Guo J. Arbuscular mycorrhizal fungi alleviate phosphorus limitation by reducing plant N:P ratios under warming and nitrogen addition in a temperate meadow ecosystem. Sci Total Environ 2019; 686:1129-1139. [PMID: 31412509 DOI: 10.1016/j.scitotenv.2019.06.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 06/10/2023]
Abstract
Global change apart from ecosystem processes also influences the community structure of key organisms, such as arbuscular mycorrhizal fungi (AMF). We conducted a 3-year experiment where we suppressed with benomyl mycorrhiza to understand how AMF alter the plant community structure under warming and nitrogen (N) addition. The elemental content and foliar tissue stoichiometry of the dominant species Leymus chinensis and the subordinate species Puccinellia tenuiflora were studied along with soil nutrient stoichiometries. Overall, N addition enhanced plant N: phosphorus (P) ratios at a greater level than experimental warming did. Under global change conditions, AMF symbionts significantly increased soil available P concentrations, promoted plant P absorption and decreased the plant N:P ratios. AMF alleviate P limitation by reducing plant N:P ratios. Our results highlight that the negative influence of global change on plant productivity might cancel each other out through the additive effects of AMF and that global change will increase the dependency of plants on their mycorrhizal symbionts.
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Affiliation(s)
- Linlin Mei
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China
| | - Xue Yang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China
| | - Shuaiqing Zhang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China
| | - Tao Zhang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
| | - Jixun Guo
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
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13
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Zhang ZW, Fu YF, Zhou YH, Wang CQ, Lan T, Chen GD, Zeng J, Chen YE, Yuan M, Yuan S, Hu JY. Nitrogen and nitric oxide regulate Arabidopsis flowering differently. Plant Sci 2019; 284:177-184. [PMID: 31084870 DOI: 10.1016/j.plantsci.2019.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/02/2019] [Accepted: 04/17/2019] [Indexed: 05/27/2023]
Abstract
Both nitrogen (N) and nitric oxide (NO) postpone plant flowering. However, we still don't know whether N and NO trigger the same signaling pathways leading to flowering delay. Our previous study found that ferredoxin NADP+ oxidoreductase (FNR1) and the blue-light receptor cryptochrome 1 (CRY1) are involved in nitrogen-regulated flowering-time control. However, NO-induced late-flowering does not require FNR1 or CRY1. Sucrose supply counteracts the flowering delay induced by NO. However high-N-induced late-flowering could not be reversed by 5% sucrose supplementation. The high nitrogen condition decreased the amplitudes of all transcripts of the circadian clock. While NO increased the amplitudes of circadian transcripts of CRY1, LHY (LATE ELONGATED HYPOCOTYL), CCA1 (CIRCADIAN CLOCK ASSOCIATED 1) and TOC1 (TIMING OF CAB EXPRESSION 1), but decreased the amplitudes of circadian transcripts of CO (CONSTANS) and GI (GIGANTEA). 5% sucrose supplementation reversed the declines in amplitudes of circadian transcripts of CO and GI after the NO treatment. NO induced S-nitrosation modification on oscillators CO and GI, but not on the other oscillators of the circadian clock. Sucrose supply interestingly reduced S-nitrosation levels of GI and CO proteins. Thus N and NO rely on overlapping but distinct signaling pathways on plant flowering.
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Affiliation(s)
- Zhong-Wei Zhang
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Yu-Fan Fu
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Yang-Hong Zhou
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Chang-Quan Wang
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Ting Lan
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Guang-Deng Chen
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Jian Zeng
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China
| | - Ming Yuan
- College of Life Sciences, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China
| | - Shu Yuan
- College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Jin-Yao Hu
- Research Center for Eco-Enviromental Engineering, Mianyang Normal University, Mianyang, 621000, Sichuan, China.
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14
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Wang M, Gu Z, Wang R, Guo J, Ling N, Firbank LG, Guo S. Plant Primary Metabolism Regulated by Nitrogen Contributes to Plant-Pathogen Interactions. Plant Cell Physiol 2019; 60:329-342. [PMID: 30388252 DOI: 10.1093/pcp/pcy211] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 10/27/2018] [Indexed: 06/08/2023]
Abstract
Nitrogen contributes to plant defense responses by the regulation of plant primary metabolism during plant-pathogen interactions. Based on biochemical, physiological, bioinformatic and transcriptome approaches, we investigated how different nitrogen forms (ammonium vs. nitrate) regulate the physiological response of cucumber (Cucumis sativus) to Fusarium oxysporum f. sp. cucumerinum (FOC) infection. The metabolic profile revealed that nitrate-grown plants accumulated more organic acids, while ammonium-grown plants accumulated more amino acids; FOC infection significantly increased levels of both amino acids and organic acids in the roots of ammonium-grown plants. Transcriptome analysis showed that genes related to carbon metabolism were mostly up-regulated in plants grown with nitrate, whereas in ammonium-grown plants the up-regulated genes were mostly those that were related to primary nitrogen metabolism. Root FOC colonization and disease incidence were positively correlated with levels of root amino acids and negatively correlated with levels of root organic acids. In conclusion, organic acid metabolism and expression of related genes increased under nitrate, whereas ammonium increased the level of amino acids and expression of related genes; these altered levels of organic acids and amino acids resulted in different tolerances to FOC infection depending on the nitrogen forms supplied.
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Affiliation(s)
- Min Wang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Zechen Gu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Ruirui Wang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Junjie Guo
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Ning Ling
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | | | - Shiwei Guo
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
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15
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Nawaz MA, Chen C, Shireen F, Zheng Z, Sohail H, Afzal M, Ali MA, Bie Z, Huang Y. Genome-wide expression profiling of leaves and roots of watermelon in response to low nitrogen. BMC Genomics 2018; 19:456. [PMID: 29898660 PMCID: PMC6001020 DOI: 10.1186/s12864-018-4856-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 06/06/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Nitrogen (N) is a key macronutrient required for plant growth and development. In this study, watermelon plants were grown under hydroponic conditions at 0.2 mM N, 4.5 mM N, and 9 mM N for 14 days. RESULTS Dry weight and photosynthetic assimilation at low N (0.2 mM) was reduced by 29 and 74% compared with high N (9 mM). The photochemical activity (Fv/Fm) was also reduced from 0.78 at high N to 0.71 at low N. The N concentration in the leaf, stem, and root of watermelon under low N conditions was reduced by 68, 104, and 108%, respectively compared with 9 mM N treatment after 14 days of N treatment. In the leaf tissues of watermelon grown under low N conditions, 9598 genes were differentially expressed, out of which 4533 genes (47.22%) were up-regulated whereas, 5065 genes (52.78%) were down-regulated compared with high N. Similarly in the root tissues, 3956 genes were differentially expressed, out of which 1605 genes were up-regulated (40.57%) and 2351 genes were down-regulated (59.43%), compared with high N. Our results suggest that leaf tissues are more sensitive to N deficiency compared with root tissues. The gene ontology (GO) analysis showed that the availability of N significantly affected 19 biological processes, 8 cell component metabolic pathways, and 3 molecular functions in the leaves; and 13 biological processes, 12 molecular functions, and 5 cell component metabolic pathways in the roots of watermelon. The low affinity nitrate transporters, high affinity nitrate transporters, ammonium transporters, genes related with nitrogen assimilation, and chlorophyll and photosynthesis were expressed differentially in response to low N. Three nitrate transporters (Cla010066, Cla009721, Cla012765) substantially responded to low nitrate supply in the root and leaf tissues. Additionally, a large number of transcription factors (1365) were involved in adaptation to low N availability. The major transcription factor families identified in this study includes MYB, AP2-EREBP, bHLH, C2H2 and NAC. CONCLUSION Candidate genes identified in this study for nitrate uptake and transport can be targeted and utilized for further studies in watermelon breeding and improvement programs to improve N uptake and utilization efficiency.
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Affiliation(s)
- Muhammad Azher Nawaz
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
- University College of Agriculture, University of Sargodha, Sargodha, Pakistan
| | - Chen Chen
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Fareeha Shireen
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Zhuhua Zheng
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Hamza Sohail
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Muhammad Afzal
- University College of Agriculture, University of Sargodha, Sargodha, Pakistan
| | - Muhammad Amjad Ali
- Department of Plant Pathology, and Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Pakistan
| | - Zhilong Bie
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Yuan Huang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
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Yu Q, Wang HJ, Wang HZ, Li Y, Liang XM, Xu C, Jeppesen E. Does the responses of Vallisneria natans (Lour.) Hara to high nitrogen loading differ between the summer high-growth season and the low-growth season? Sci Total Environ 2017; 601-602:1513-1521. [PMID: 28605869 DOI: 10.1016/j.scitotenv.2017.05.268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 05/28/2023]
Abstract
Loss of submersed macrophytes is a world-wide phenomenon occurring when shallow lakes become eutrophic due to excess nutrient loading. In addition to the well-known effect of phosphorus, nitrogen as a trigger of macrophyte decline has received increasing attention. The precise impact of high nitrogen concentrations is debated, and the role of different candidate factors may well change over the season. In this study, we conducted experiments with Vallisneria natans during the growing season (June-September) in 10 ponds subjected to substantial differences in nitrogen loading (five targeted total nitrogen concentrations: control, 2, 10, 20, and 100mgL-1) and compared the results with those obtained in our earlier published study from the low-growth season (December-April). Like in the low-growth season, growth of V. natans in summer declined with increasing ammonium (NH4) concentrations and particularly with increasing phytoplankton chlorophyll a (ChlaPhyt). Accordingly, we propose that shading by phytoplankton might be of key importance for macrophyte decline, affecting also periphyton growth as periphyton chlorophyll a (ChlaPeri) decreased with increasing ChlaPhyt. Free amino acid contents (FAA) of plants tended to increase with increasing NH4 concentrations, while the relationships between FAA with growth indices were all weak, suggesting that FAA might be a useful indicator of the physiological stress of the plants but not of macrophyte growth. Taken together, the results from the two seasons indicate that although a combination of high nitrogen concentrations (ammonium) and shading by phytoplankton may cause severe stress on macrophytes, active growth in the growing season enabled them to partly overcome the stress.
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Affiliation(s)
- Qing Yu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Hai-Jun Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Hong-Zhu Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yan Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Min Liang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Chi Xu
- School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Erik Jeppesen
- Department of Bioscience and Arctic Research Centre, Aarhus University, 8600 Silkeborg, Denmark; Sino Danish Centre for Education and Research (SDC), Beijing, China
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17
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Wang YM, Wang P, Hao XZ, Zhou DM, Li JZ. Effect of different nitrogen forms on the toxicity of Zn in wheat seedling root: a modeling analysis. Environ Sci Pollut Res Int 2017; 24:18896-18906. [PMID: 28653200 DOI: 10.1007/s11356-017-9495-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 06/08/2017] [Indexed: 06/07/2023]
Abstract
Heavy metal stress in culture media is always rhizotoxic. Our study aims to investigate the role of negative potential (ψ 0) at root cell membrane surface (CMs) on modeling Zn2+ toxicity to wheat seedling roots and to examine the effects of different nitrogen forms (NH4+ and NO3-) on ψ 0 and Zn rhizotoxicity. Solution culture experiments were conducted to measure the root elongation and Zn accumulation under Zn2+ exposure. The role of two nitrogen forms in affecting Zn2+ toxicity was compared, giving particular consideration to ψ 0 and Zn2+ activities at CMs ({Zn2+}0). Results showed that NH4+ alleviates Zn2+ rhizotoxicity and NO3- increases Zn2+ rhizotoxicity. In modeling the rhizotoxicity, root length correlated better with {Zn2+}0 than {Zn2+}b, and the predictive accuracy (r 2) of NH4+ treatment increased from 0.748 to 0.917 when incorporation of {Zn2+}0 and {Ca2+}0 into analysis. Oppositely, ψ 0 played a limited role in modeling Zn2+ rhizotoxicity and bioavailability in NO3- treated medium (r 2 = 0.609). Moreover, higher concentration of Zn in roots was found in NO3- treatment, compared with the NH4+ treatment. ψ 0 rather than the rhizotoxicity data correlated better with Zn accumulation especially in the NO3- treatment (r 2 > 0.7), which meant the electrical driving force at CMs playing a dominant role in modeling the metal accumulation. In conclusion, the alleviatory role of NH4+ on Zn toxicity and uptake was well explained and modeled by electrostatic effects at CMs. Though our data do not explore mechanisms for the NO3--Zn2+ interactions, we propose that ψ 0 worked better in affecting the driving force for root Zn uptake, than influencing metal bioavailability at CMs.
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Affiliation(s)
- Yi-Min Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Peng Wang
- School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Xiu-Zhen Hao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Dong-Mei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Ji-Zhou Li
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
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Song M, Yu L, Jiang Y, Lei Y, Korpelainen H, Niinemets Ü, Li C. Nitrogen-controlled intra- and interspecific competition between Populus purdomii and Salix rehderiana drive primary succession in the Gongga Mountain glacier retreat area. Tree Physiol 2017; 37:799-814. [PMID: 28338926 DOI: 10.1093/treephys/tpx017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
In this study, intra- and interspecific competition were investigated in early successional Salix rehderiana Schneider and later-appearing Populus purdomii Rehder under non-fertilized (control) and nitrogen (N)-fertilized conditions in the Hailuogou glacier retreat area. Our aim was to discover whether N is a key factor in plant-plant competition and whether N drives the primary succession process in a glacier retreat area. We analyzed differences in responses to intra- and interspecific competition and N fertilization between P. purdomii and S. rehderiana, including parameters such as biomass accumulation, nutrient absorption, non-structural carbohydrates, photosynthetic capacity, hydrolysable amino acids and leaf ultrastructure. In the control treatments, S. rehderiana individuals subjected to interspecific competition benefited from the presence of P. purdomii plants, as indicated by higher levels of biomass accumulation, photosynthetic capacity, N absorption, amino acid contents and photosynthetic N-use efficiency. However, in the N-fertilized treatments, P. purdomii individuals exposed to interspecific competition benefited from the presence of S. rehderiana plants, as shown by a higher growth rate, enhanced carbon gain capacity, greater amino acid contents, and elevated water-use efficiency, whereas the growth of S. rehderiana was significantly reduced. Our results demonstrate that N plays a pivotal role in determining the asymmetric competition pattern among Salicaceae species during primary succession. We argue that the interactive effects of plant-plant competition and N availability are key mechanisms that drive primary succession in the Gongga Mountain glacier retreat area.
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Affiliation(s)
- Mengya Song
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Lei Yu
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yonglei Jiang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yanbao Lei
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
| | - Helena Korpelainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, P.O. Box 27,University of Helsinki, HelsinkiFI-00014, Finland
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia
| | - Chunyang Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
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Delavaux CS, Camenzind T, Homeier J, Jiménez-Paz R, Ashton M, Queenborough SA. Nutrient enrichment effects on mycorrhizal fungi in an Andean tropical montane Forest. Mycorrhiza 2017; 27:311-319. [PMID: 27924430 DOI: 10.1007/s00572-016-0749-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
Nitrogen (N) and phosphorus (P) deposition are increasing worldwide largely due to increased fertilizer use and fossil fuel combustion. Most work with N and P deposition in natural ecosystems has focused on temperate, highly industrialized, regions. Tropical regions are becoming more developed, releasing large amounts of these nutrients into the atmosphere. Nutrient enrichment in nutrient-poor systems such as tropical montane forest can represent a relatively large shift in nutrient availability, especially for sensitive microorganisms such as arbuscular mycorrhizal fungi (AMF). These symbiotic fungi are particularly critical, given their key role in ecosystem processes affecting plant community structure and function.To better understand the consequences of nutrient deposition in plant communities, a long-term nutrient addition experiment was set up in a tropical montane forest in the Andes of southern Ecuador. In this study, we investigated the impacts of 7 years of elevated N and P on AMF root colonization potential (AMF-RCP) through a greenhouse bait plant method in which we quantified root colonization. We also examined the relationship between AMF-RCP and rarefied tree diversity.After 7 years of nutrient addition, AMF-RCP was negatively correlated with soil P, positively correlated with soil N, and positively correlated with rarefied tree diversity. Our results show that AMF in this tropical montane forest are directly affected by soil N and P concentrations, but may also be indirectly impacted by shifts in rarefied tree diversity. Our research also highlights the need to fully understand the benefits and drawbacks of using different sampling methods (e.g., AMF-RCP versus direct root sampling) to robustly examine AMF-plant interactions in the future.
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Affiliation(s)
- Camille S Delavaux
- Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA.
- Ecology and Evolutionary Biology, University of Kansas, Room 9, Takeru Higuchi Hall, Lawrence, KS, 66047, USA.
| | - Tessa Camenzind
- Institute of Biology, Freie Universität Berlin, Altensteinstr. 6, 14195, Berlin, Germany
- Berlin- Brandenburg Institute of Advanced Biodiversity Research, Plant Ecology, 14195, Berlin, Germany
| | - Jürgen Homeier
- Albrecht von Haller Institute of Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Rosa Jiménez-Paz
- Laboratorio de Ecología de Plantas, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de octubre 1076 y Roca, Apdo. 17-01-2184, Quito, Ecuador
| | - Mark Ashton
- Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA
| | - Simon A Queenborough
- Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect St, New Haven, CT, 06511, USA
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20
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Affiliation(s)
- Alain Gojon
- UMR Biochimie & Physiologie Moléculaire des Plantes - (B&PMP), CNRS-INRA-SUPAGRO-UM, Campus INRA / SupAgro, Place Pierre Viala –, Montpellier Cedex, France
- Correspondence:
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Vellend M, Baeten L, Becker-Scarpitta A, Boucher-Lalonde V, McCune JL, Messier J, Myers-Smith IH, Sax DF. Plant Biodiversity Change Across Scales During the Anthropocene. Annu Rev Plant Biol 2017; 68:563-586. [PMID: 28125286 DOI: 10.1146/annurev-arplant-042916-040949] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Plant communities have undergone dramatic changes in recent centuries, although not all such changes fit with the dominant biodiversity-crisis narrative used to describe them. At the global scale, future declines in plant species diversity are highly likely given habitat conversion in the tropics, although few extinctions have been documented for the Anthropocene to date (<0.1%). Nonnative species introductions have greatly increased plant species richness in many regions of the world at the same time that they have led to the creation of new hybrid polyploid species by bringing previously isolated congeners into close contact. At the local scale, conversion of primary vegetation to agriculture has decreased plant diversity, whereas other drivers of change-e.g., climate warming, habitat fragmentation, and nitrogen deposition-have highly context-dependent effects, resulting in a distribution of temporal trends with a mean close to zero. These results prompt a reassessment of how conservation goals are defined and justified.
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Affiliation(s)
- Mark Vellend
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada;
| | - Lander Baeten
- Forest and Nature Lab, Department of Forest and Water Management, Ghent University, BE-9090 Melle-Gontrode, Belgium
| | | | | | - Jenny L McCune
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Julie Messier
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada;
| | - Isla H Myers-Smith
- School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Dov F Sax
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912
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22
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Munzi S, Sheppard LJ, Leith ID, Cruz C, Branquinho C, Bini L, Gagliardi A, Cai G, Parrotta L. The cost of surviving nitrogen excess: energy and protein demand in the lichen Cladonia portentosa as revealed by proteomic analysis. Planta 2017; 245:819-833. [PMID: 28054148 DOI: 10.1007/s00425-017-2647-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/01/2017] [Indexed: 05/10/2023]
Abstract
Different nitrogen forms affect different metabolic pathways in lichens. In particular, the most relevant changes in protein expression were observed in the fungal partner, with NO 3- mostly affecting the energetic metabolism and NH 4+ affecting transport and regulation of proteins and the energetic metabolism much more than NO 3- did. Excess deposition of reactive nitrogen is a well-known agent of stress for lichens, but which symbiont is most affected and how, remains a mystery. Using proteomics can expand our understanding of stress effects on lichens. We investigated the effects of different doses and forms of reactive nitrogen, with and without supplementary phosphorus and potassium, on the proteome of the lichen Cladonia portentosa growing in a 'real-world' simulation of nitrogen deposition. Protein expression changed with the nitrogen treatments but mostly in the fungal partner, with NO3- mainly affecting the energetic metabolism and NH4+ also affecting the protein synthesis machinery. The photobiont mainly responded overexpressing proteins involved in energy production. This suggests that in response to nitrogen stress, the photobiont mainly supports the defensive mechanisms initiated by the mycobiont with an increased energy production. Such surplus energy is then used by the cell to maintain functionality in the presence of NO3-, while a futile cycle of protein production can be hypothesized to be induced by NH4+ excess. External supply of potassium and phosphorus influenced differently the responses of particular enzymes, likely reflecting the many processes in which potassium exerts a regulatory function.
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Affiliation(s)
- Silvana Munzi
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016, Lisbon, Portugal.
| | - Lucy J Sheppard
- Centre for Ecology and Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, EH26 0QB, UK
| | - Ian D Leith
- Centre for Ecology and Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, EH26 0QB, UK
| | - Cristina Cruz
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016, Lisbon, Portugal
| | - Cristina Branquinho
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016, Lisbon, Portugal
| | - Luca Bini
- Department of Life Sciences, University of Siena, Via Aldo Moro, 2, 53100, Siena, Italy
| | - Assunta Gagliardi
- Department of Life Sciences, University of Siena, Via Aldo Moro, 2, 53100, Siena, Italy
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, Via Pier Andrea Mattioli, 4, 53100, Siena, Italy
| | - Luigi Parrotta
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio, 42, 40126, Bologna, Italy
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23
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Gong XY, Schäufele R, Schnyder H. Bundle-sheath leakiness and intrinsic water use efficiency of a perennial C4 grass are increased at high vapour pressure deficit during growth. J Exp Bot 2017; 68:321-333. [PMID: 27864539 PMCID: PMC5853292 DOI: 10.1093/jxb/erw417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/20/2016] [Indexed: 05/05/2023]
Abstract
Bundle-sheath leakiness (ϕ) is a key parameter of the CO2-concentrating mechanism of C4 photosynthesis and is related to leaf-level intrinsic water use efficiency (WUEi). This work studied short-term dynamic responses of ϕ to alterations of atmospheric CO2 concentration in Cleistogenes squarrosa, a perennial grass, grown at high (1.6 kPa) or low (0.6 kPa) vapour pressure deficit (VPD) combined with high or low N supply in controlled environment experiments. ϕ was determined by concurrent measurements of photosynthetic gas exchange and on-line carbon isotope discrimination, using a new protocol. Growth at high VPD led to an increase of ϕ by 0.13 and a concurrent increase of WUEi by 14%, with similar effects at both N levels. ϕ responded dynamically to intercellular CO2 concentration (C i), increasing with C i Across treatments, ϕ was negatively correlated to the ratio of CO2 saturated assimilation rate to carboxylation efficiency (a proxy of the relative activities of Rubisco and phosphoenolpyruvate carboxylase) indicating that the long-term environmental effect on ϕ was related to the balance between C3 and C4 cycles. Our study revealed considerable dynamic and long-term variation in ϕ of C. squarrosa, suggesting that ϕ should be determined when carbon isotope discrimination is used to assess WUEi Also, the data indicate a trade-off between WUEi and energetic efficiency in C. squarrosa.
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Affiliation(s)
- Xiao Ying Gong
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
| | - Rudi Schäufele
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, Alte Akademie 12, 85354 Freising, Germany
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24
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David LC, Berquin P, Kanno Y, Seo M, Daniel-Vedele F, Ferrario-Méry S. N availability modulates the role of NPF3.1, a gibberellin transporter, in GA-mediated phenotypes in Arabidopsis. Planta 2016; 244:1315-1328. [PMID: 27541496 DOI: 10.1007/s00425-016-2588-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/12/2016] [Indexed: 05/20/2023]
Abstract
AtNPF3.1 gene expression is promoted by limiting nitrogen nutrition. Atnpf3.1 mutants are affected in hypocotyl elongation and seed germination under conditions of low-nitrate availability. The NITRATE TRANSPORTER1/PEPTIDE TRANSPORTER (NPF) family encodes nitrate or peptides transporters, some of which are also able to transport hormones. AtNPF3.1 has been described as a nitrate/nitrite/gibberellin transporter. Until now only its gibberellins (GAs) transport capacity have been proven in planta. We further analyzed its substrate specificity towards different GA species using a yeast heterologous system which revealed that (1) NPF3.1 transported not only bioactive GAs but also their precursors and metabolites and (2) the GAs' import activity of NPF3.1 was not affected by the presence of exogenous nitrate. Gene expression analysis along with germination assays and hypocotyl length measurements of loss of function mutants was used to understand the in planta role of NPF3.1. GUS staining revealed that this gene is expressed mainly in the endodermis of roots and hypocotyls, in shoots, stamens, and dry seeds. Germination assays in the presence of paclobutrazol, a GA biosynthesis inhibitor, revealed that the germination rate of npf3.1 mutants was lower compared to wild type when GA was added at the same time. Likewise, hypocotyl length measurements showed that the npf3.1 mutants were less sensitive to exogenous GA addition in the presence of paclobutrazol, compared to wild type. Moreover, this phenotype was observed only when plants were grown on low-nitrate supply. In addition, NPF3.1 gene expression was upregulated by low exogenous nitrate concentrations and the npf3.1 mutants exhibited a not yet described GA-related phenotype under these conditions. All together, these results indicated that NPF3.1 is indeed involved in GAs transport in planta under low-nitrate conditions.
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Affiliation(s)
- Laure C David
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
| | - Patrick Berquin
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
| | - Yuri Kanno
- RIKEN Center for Sustainable Resource Science Yokohama, Kanagawa, 230-0045, Japan
| | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science Yokohama, Kanagawa, 230-0045, Japan
| | - Françoise Daniel-Vedele
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France
| | - Sylvie Ferrario-Méry
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles, France.
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25
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Li L, Shi X, Zheng F, Li C, Wu D, Bai G, Gao D, Wu J, Li T. A novel nitrogen-dependent gene associates with the lesion mimic trait in wheat. Theor Appl Genet 2016; 129:2075-2084. [PMID: 27460590 DOI: 10.1007/s00122-016-2758-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/22/2016] [Indexed: 05/24/2023]
Abstract
Using bulk segregant analysis (BSA) coupling with RNA-seq and DNA markers identified a potentially novel nitrogen-dependent lesion mimic gene Ndhrl1 on 2BS in wheat. Lesion mimic (LM) refers to hypersensitive reaction-like (HRL) traits that appear on leaf tissue in the absence of plant pathogens. In a wheat line P7001, LM showed up on the leaves under the 0 g nitrogen (N) treatment, but disappeared when sufficient N was supplied, suggesting that LM is N-responsive and N dosage dependent. Using BSA strategy together with RNA-seq and DNA markers, we identified an N-dependent LM gene (Ndhrl1) and mapped it to the short arm of chromosome 2B using an F5 recombinant inbred population developed from the cross of P7001 × P216. The putative gene was delimited into an interval of 8.1 cM flanked by the CAPS/dCAPS markers 7hrC9 and 7hr2dc14, and co-segregated with the dCAPS marker 7hrdc2. This gene is most likely a novel gene for LM in wheat based on its chromosomal location. Further analysis of RNA-seq data showed that plant-pathogen interaction, nitrogen metabolism, zeatin biosynthesis and plant hormone signal transduction pathways were significantly differentially expressed between LM and non-LM lines.
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Affiliation(s)
- Lei Li
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China
- College of Plant Protection, Yangzhou University, Yangzhou, 225009, China
| | - Xuan Shi
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Fei Zheng
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Changcheng Li
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Di Wu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Guihua Bai
- Lixiahe Agricultural Research Institute of Jiangsu Province, Yangzhou, 225000, China
- Department of Agronomy, Kansas State University, Manhattan, KS, 66506, USA
| | - Derong Gao
- USDA-ARS Hard Winter Wheat Genetics Research Unit, Manhattan, KS, 66506, USA
| | - Jincai Wu
- College of Plant Protection, Yangzhou University, Yangzhou, 225009, China
| | - Tao Li
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
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26
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Gu DY, Wang XF, Yang FJ, Jiao J, Wei M, Shi QH. [Effects of purified humic acid on growth and nutrient absorption of cucumber (Cucumis sativus)seedlings under low nitrogen stress.]. Ying Yong Sheng Tai Xue Bao 2016; 27:2535-2542. [PMID: 29733141 DOI: 10.13287/j.1001-9332.201608.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Taking 'Xintaimici' and 'Jinyou 1' as experimental cucumber cultivars, this paper studied the effects of watering purified humic acid (PHA) at different levels (0, 50, 100, 150, 200 mg·L-1) on growth and nutrient absorption of cucumber seedlings under low nitrogen stress (1 mmol·L-1 NO3-) in sand culture pots. The results showed that, under low N condition, PHA could significantly increase the total root length, root surface area, root tip number and root volume of cucumber seedlings, and promote plant height, stem diameter and leaf area. Proline and soluble sugar contents in cucumber leaves were significantly increased by PHA. The absorption of N, P, K, Ca, Mg, Fe in cucumber seedlings was promoted. According to the response of the two cucumber cultivars to PHA under low N stress, some traits of two cultivars showed different sensitivity to PHA level. The comprehensive analysis of the above results inferred that the PHA level from 100 mg·L-1 to 150 mg·L-1 could significantly enhance the growth and nutrient absorption of cucumber seedlings.
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Affiliation(s)
- Duan Yin Gu
- College of Horticulture Science and Enginee-ring, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Xiu Feng Wang
- College of Horticulture Science and Enginee-ring, Shandong Agricultural University, Tai'an 271018, Shandong, China
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, Chin
| | - Feng Juan Yang
- College of Horticulture Science and Enginee-ring, Shandong Agricultural University, Tai'an 271018, Shandong, China
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, Chin
| | - Juan Jiao
- Tai'an Academy of Agricultural Sciences, Tai'an 271000, Shandong, China
| | - Min Wei
- College of Horticulture Science and Enginee-ring, Shandong Agricultural University, Tai'an 271018, Shandong, China
- Scientific Observing and Experimental Station of Environment Controlled Agricultural Engineering in Huang-Huai-Hai Region, Ministry of Agriculture, Tai'an 271018, Shandong, China
| | - Qing Hua Shi
- College of Horticulture Science and Enginee-ring, Shandong Agricultural University, Tai'an 271018, Shandong, China
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, Chin
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27
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Chang Z, Liu Y, Dong H, Teng K, Han L, Zhang X. Effects of Cytokinin and Nitrogen on Drought Tolerance of Creeping Bentgrass. PLoS One 2016; 11:e0154005. [PMID: 27099963 PMCID: PMC4839601 DOI: 10.1371/journal.pone.0154005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Cytokinin (CK) is a vital plant hormone that controls many aspects of growth and development in plants. Nitrogen (N) is the indispensable macronutrient needed in plants and also one of the most important limiting factors for plant growth. This study was designed to investigate the simultaneous effects of CK and N on the visual turf quality and antioxidant metabolism of drought-stressed creeping bentgrass (Agrostis stolonifera L.). 'PennA-4' creeping bentgrass treated with trans-zeatin riboside at three rates of CK concentrations of 0, 10 and 100 μM (designated by CK0, 10, and 100) and two nitrogen rates with 2.5 and 7.5 kg N·ha-1 every 15 days (designated by low and high N) in a complete factorial arrangement was grown under two soil moisture regimes: well-watered and drought stress. Exogenous CK improved turf quality and delayed leaf wilting under drought stress, especially under high N. The grasses treated with CK10 and CK100 had lower O2- production and H2O2 concentration than those without CK treatment. The CK100 treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and guaiacol peroxidase (POD) by 25%, 22%, 17% and 24%, respectively, relative to CK0. Moreover, the activity changes of the antioxidant enzyme isoforms were more significant under high N condition relative to low N condition. Our results demonstrated the beneficial impacts of CK and N on physiological reactions, especially antioxidant metabolism, and foliar application of CK at 10 or 100 μM plus 7.5 kg ha-1 N biweekly may improve drought stress resistance of creeping bentgrass.
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Affiliation(s)
- Zhihui Chang
- College of Forestry, Beijing Forestry University, Beijing, 100083, P.R. China
| | - Yang Liu
- College of Forestry, Beijing Forestry University, Beijing, 100083, P.R. China
| | - Hui Dong
- College of Forestry, Beijing Forestry University, Beijing, 100083, P.R. China
| | - Ke Teng
- College of Forestry, Beijing Forestry University, Beijing, 100083, P.R. China
| | - Liebao Han
- College of Forestry, Beijing Forestry University, Beijing, 100083, P.R. China
| | - Xunzhong Zhang
- Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061, United States of America
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28
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Kerpel-Fronius E. Evolution of knowledge on infantile dehydration. Contrib Nephrol 2015; 21:62-7. [PMID: 7389368 DOI: 10.1159/000385248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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29
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Neal K, Eun JS, Young AJ, Mjoun K, Hall JO. Feeding protein supplements in alfalfa hay-based lactation diets improves nutrient utilization, lactational performance, and feed efficiency of dairy cows. J Dairy Sci 2014; 97:7716-28. [PMID: 25262186 DOI: 10.3168/jds.2014-8033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 08/15/2014] [Indexed: 11/19/2022]
Abstract
Due to the increasing cost of soybean meal and concerns of excess N being excreted into the environment, new protein supplements have been developed. Two products that have shown potential in increasing N utilization efficiency are slow-release urea (SRU; Optigen; Alltech Inc., Nicholasville, KY) and ruminal-escape protein derived from yeast (YMP; DEMP; Alltech Inc.). The objective of this study was to assess the effects of feeding these 2 supplements in alfalfa hay-based [45.7% of forage dietary dry matter (DM)] dairy diets on nutrient utilization, feed efficiency, and lactational performance of dairy cows. Twelve multiparous dairy cows were used in a triple 4 × 4 Latin square design with one square consisting of ruminally cannulated cows. Treatments included (1) control, (2) SRU-supplemented total mixed ration (SRUT), (3) YMP-supplemented total mixed ration (YMPT), and (4) SRU- and YMP-supplemented total mixed ration (SYT). The control consisted only of a mixture of soybean meal and canola meal in a 50:50 ratio. The SRU and the YMP were supplemented at 0.49 and 1.15% DM, respectively. The experiment consisted of 4 periods lasting 28 d each (21 d of adaptation and 7 d of sampling). Cows fed YMPT and SYT had decreased intake of DM, and all supplemented treatments had lower crude protein intake compared with those fed the control. Milk yield tended to have the greatest increase in YMPT compared with the control (41.1 vs. 39.7 kg/d) as well as a tendency for increased milk fat and protein yields. Feed efficiencies based on yields of milk, 3.5% fat-corrected milk, and energy-corrected milk increased at 10 to 16% due to protein supplementation. Cows fed protein supplements partitioned less energy toward body weight gain, but tended to partition more energy toward milk production. Efficiency of use of feed N to milk N increased by feeding SRUT and YMPT, and milk N-to-manure N ratio increased with YMPT. Overall results from this experiment indicate that replacing the mixture of soybean meal and canola meal with SRU and YMP in alfalfa hay-based dairy diets can be a good approach to improve nutrient utilization efficiencies in lactating dairy cows.
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Affiliation(s)
- K Neal
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan 84322
| | - J-S Eun
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan 84322.
| | - A J Young
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan 84322
| | - K Mjoun
- Alltech, Brookings, SD 57006
| | - J O Hall
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan 84322
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López MC, Estellés F, Moya VJ, Fernández C. Use of dry citrus pulp or soybean hulls as a replacement for corn grain in energy and nitrogen partitioning, methane emissions, and milk performance in lactating Murciano-Granadina goats. J Dairy Sci 2014; 97:7821-32. [PMID: 25459909 DOI: 10.3168/jds.2014-8424] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 09/12/2014] [Indexed: 12/16/2023]
Abstract
The aim of this study was to assess the effect of substitution of dietary corn grain by dry citrus pulp or soybean hulls on energy and nitrogen partitioning, substrate oxidation, methane emission, and milk performance in dairy goats during midlactation. Twelve multiparous Murciano-Granadina goats of similar body weight (41.7 ± 2.8 kg) were split in 3 groups in an incomplete crossover design. One group of 4 goats was fed a mixed ration with 605 g/kg of dry matter of corn grain (CRG), another group replaced corn grain with dry citrus pulp (CTP), and the last with soybean hulls (SYH). The goats were allocated to individual metabolism cages. After 14 d of adaptation, feed intake, total fecal and urine output, and milk yield were recorded daily over a 5-d period. Then, gas exchange measurements were recorded by a mobile open-circuit indirect calorimetry system using a head box. Dry matter intake was similar for all 3 groups (1.53 kg/d, on average). Total replacement of the concentrate with fibrous by-products increased fiber apparent digestibility. The metabolizable energy intake was significantly greater for diet CRG than SYH (1,193 vs. 1,079 kJ/kg of BW⁰·⁷⁵, respectively), CTP showed an intermediate value. The heat production was higher for the fiber diet than starchy diet (908 vs. 843 kJ/kg of BW⁰·⁷⁵ for SYH and CRG, respectively). The efficiency of use of metabolizable energy for milk production obtained by regression was 0.59. Goats fed CTP and SYH diets produced similar CH₄ emissions (34.8 g/d, on average), significantly higher compared with goats fed the CRG diet (24.7 g/d). Goats of the 3 treatments were in negative energy balance, so the oxidation of fat was greater than for carbohydrates. No significant differences were observed for milk production (1.72 kg/d), and milk fat was significantly greater for a more fibrous diet compared with a starchy diet (6.57 vs. 4.95% in SYH and CRG, respectively).
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Affiliation(s)
- M C López
- Institute for Animal Science and Technology, Polytechnic University of Valencia, 46022 Valencia, Spain
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Abstract
Root system architecture is a fundamentally important trait for resource acquisition in both ecological and agronomic contexts. Because of the plasticity of root development and the almost infinite complexity of the soil, root system architecture is shaped by environmental factors to a much greater degree than shoot architecture. In attempting to understand how roots sense and respond to environmental cues, the striking effects of nitrate and other forms of nitrogen on root growth and branching have received particular attention. This minireview focuses on the latest advances in our understanding of the diverse nitrogen signalling pathways that are now known to act at multiple stages in the process of lateral root development, as well as on primary root growth.
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Affiliation(s)
- Brian G Forde
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
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Xu Y, Wang R, Tong Y, Zhao H, Xie Q, Liu D, Zhang A, Li B, Xu H, An D. Mapping QTLs for yield and nitrogen-related traits in wheat: influence of nitrogen and phosphorus fertilization on QTL expression. Theor Appl Genet 2014; 127:59-72. [PMID: 24072207 DOI: 10.1007/s00122-013-2201-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 09/17/2013] [Indexed: 05/21/2023]
Abstract
The present study identified some new important genomic regions and demonstrated the availability of conditional analysis in dissecting QTLs induced by environmental factors. The high input and low use efficiency of nutrient fertilizers require knowledge of the genetic control of crop reaction to nutrient supplements. In this study, 14 morphological and 8 physiological traits of a set of 182 wheat (Triticum aestivum L.) recombinant inbred lines (Xiaoyan 54 × Jing 411) were investigated in six environments to map quantitative trait loci (QTLs). The influence of nitrogen (N) and phosphorus (P) fertilization on QTL expression was studied by unconditional and conditional analysis. A total of 117 and 30 QTLs were detected by unconditional and conditional analysis, respectively, among which 21 were common for both methods. Thirty-four QTL clusters were identified. Eighteen conserved QTLs (15.4 % of the 117 QTLs) between years, but within nutritional treatment were found. The three major QTLs on chromosomes 2D, 4B and 6A were coincident with Rht8, Rht-B1b and TaGW2, respectively. The other two important intervals on chromosomes 4B and 7A for yield component traits were newly detected QTLs that warrant further study. By conditional analysis, spikelet number per spike was found to be induced by P fertilization mostly, whereas N fertilization had more effects on the expression of the QTLs for nitrogen concentration and utilization efficiency traits. QTLs that respond to N and P interactions were also detected. The results are helpful for understanding the genetic basis of N utilization efficiency in wheat under different N and P supplement environments and provide evidence for the availability of conditional analysis in dissecting QTLs induced by environmental factors.
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Affiliation(s)
- Yunfeng Xu
- Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, 050021, China
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Kalliokoski T, Mäkinen H, Jyske T, Nöjd P, Linder S. Effects of nutrient optimization on intra-annual wood formation in Norway spruce. Tree Physiol 2013; 33:1145-1155. [PMID: 24169103 DOI: 10.1093/treephys/tpt078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the Nordic countries, growth of Norway spruce (Picea abies (L.) Karst.) is generally limited by low availability of nutrients, especially nitrogen. Optimizing forest management requires better insight on how growth responds to the environmental conditions and their manipulation. The aim of this study was to analyse the effects of nutrient optimization on timing and the rate of tracheid formation of Norway spruce and to follow the differentiation of newly formed tracheids. The study was performed during two growing seasons in a long-term nutrient optimization experiment in northern Sweden, where all essential macro- and micronutrients were supplied in irrigation water every second day from mid-June to mid-August. The control plots were without additional nutrients and water. Tracheid formation in the stem was monitored throughout the growing season by weekly sampling of microcores at breast height. The onset of xylogenesis occurred in early June, but in early summer there were no significant between-treatment differences in the onset and relative rate of tracheid formation. In both treatments, the onset of secondary cell wall formation occurred in mid-June. The maximum rate of tracheid formation occurred close to the summer solstice and 50% of the tracheids had been accumulated in early July. Optimized nutrition resulted in the formation of ∼50% more tracheids and delayed the cessation of tracheid formation, which extended the tracheid formation period by 20-50%, compared with control trees. The increased growth was mainly an effect of enhanced tracheid formation rate during the mid- and later-part of the growing season. In the second year, the increased growth rate also resulted in 11% wider tracheids. We conclude that the onset and rate of tracheid formation and differentiation during summer is primarily controlled by photoperiod, temperature and availability of nutrients, rather than supply of carbohydrates.
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Affiliation(s)
- Tuomo Kalliokoski
- Vantaa Unit, Finnish Forest Research Institute, PO Box 18, FI-01301 Vantaa, Finland
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Bay G, Nahar N, Oubre M, Whitehouse MJ, Wardle DA, Zackrisson O, Nilsson MC, Rasmussen U. Boreal feather mosses secrete chemical signals to gain nitrogen. New Phytol 2013; 200:54-60. [PMID: 23795916 DOI: 10.1111/nph.12403] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/06/2013] [Indexed: 05/13/2023]
Abstract
The mechanistic basis of feather moss-cyanobacteria associations, a main driver of nitrogen (N) input into boreal forests, remains unknown. Here, we studied colonization by Nostoc sp. on two feather mosses that form these associations (Pleurozium schreberi and Hylocomium splendens) and two acrocarpous mosses that do not (Dicranum polysetum and Polytrichum commune). We also determined how N availability and moss reproductive stage affects colonization, and measured N transfer from cyanobacteria to mosses. The ability of mosses to induce differentiation of cyanobacterial hormogonia, and of hormogonia to then colonize mosses and re-establish a functional symbiosis was determined through microcosm experiments, microscopy and acetylene reduction assays. Nitrogen transfer between cyanobacteria and Pleurozium schreberi was monitored by secondary ion mass spectrometry (SIMS). All mosses induced hormogonia differentiation but only feather mosses were subsequently colonized. Colonization on Pleurozium schreberi was enhanced during the moss reproductive phase but impaired by elevated N. Transfer of N from cyanobacteria to their host moss was observed. Our results reveal that feather mosses likely secrete species-specific chemo-attractants when N-limited, which guide cyanobacteria towards them and from which they gain N. We conclude that this signalling is regulated by N demands of mosses, and serves as a control of N input into boreal forests.
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Affiliation(s)
- Guillaume Bay
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Nurun Nahar
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Matthieu Oubre
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Martin J Whitehouse
- Department of Geosciences, Swedish Museum of Natural History, Box 50007, Stockholm, Sweden
| | - David A Wardle
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Olle Zackrisson
- The Institute for Subarctic Landscape Research, SE-930 90, Arjeplog, Sweden
| | - Marie-Charlotte Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Ulla Rasmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
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Xia J, Wan S. Independent effects of warming and nitrogen addition on plant phenology in the Inner Mongolian steppe. Ann Bot 2013; 111:1207-17. [PMID: 23585496 PMCID: PMC3662520 DOI: 10.1093/aob/mct079] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 02/19/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Phenology is one of most sensitive traits of plants in response to regional climate warming. Better understanding of the interactive effects between warming and other environmental change factors, such as increasing atmosphere nitrogen (N) deposition, is critical for projection of future plant phenology. METHODS A 4-year field experiment manipulating temperature and N has been conducted in a temperate steppe in northern China. Phenology, including flowering and fruiting date as well as reproductive duration, of eight plant species was monitored and calculated from 2006 to 2009. KEY RESULTS Across all the species and years, warming significantly advanced flowering and fruiting time by 0·64 and 0·72 d per season, respectively, which were mainly driven by the earliest species (Potentilla acaulis). Although N addition showed no impact on phenological times across the eight species, it significantly delayed flowering time of Heteropappus altaicus and fruiting time of Agropyron cristatum. The responses of flowering and fruiting times to warming or N addition are coupled, leading to no response of reproductive duration to warming or N addition for most species. Warming shortened reproductive duration of Potentilla bifurca but extended that of Allium bidentatum, whereas N addition shortened that of A. bidentatum. No interactive effect between warming and N addition was found on any phenological event. Such additive effects could be ascribed to the species-specific responses of plant phenology to warming and N addition. CONCLUSIONS The results suggest that the warming response of plant phenology is larger in earlier than later flowering species in temperate grassland systems. The effects of warming and N addition on plant phenology are independent of each other. These findings can help to better understand and predict the response of plant phenology to climate warming concurrent with other global change driving factors.
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Affiliation(s)
- Jianyang Xia
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
| | - Shiqiang Wan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
- State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, College of Life Sciences, Henan University, Kaifeng, Henan 475004, China
- For correspondence. E-mail
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Richard N, Engrola S, Palma P, Pinto W, Simes D, Conceição L. Assessment of protein digestive capacity and utilisation during ontogeny of Senegalese sole larvae: a tracer study using in vivo produced radiolabelled peptide fractions. Commun Agric Appl Biol Sci 2013; 78:396-397. [PMID: 25141722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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Mozdzer TJ, Megonigal JP. Jack-and-master trait responses to elevated CO2 and N: a comparison of native and introduced Phragmites australis. PLoS One 2012; 7:e42794. [PMID: 23118844 PMCID: PMC3485286 DOI: 10.1371/journal.pone.0042794] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 07/11/2012] [Indexed: 12/02/2022] Open
Abstract
Global change is predicted to promote plant invasions world-wide, reducing biodiversity and ecosystem function. Phenotypic plasticity may influence the ability of introduced plant species to invade and dominate extant communities. However, interpreting differences in plasticity can be confounded by phylogenetic differences in morphology and physiology. Here we present a novel case investigating the role of fitness trait values and phenotypic plasticity to global change factors between conspecific lineages of Phragmites australis. We hypothesized that due to observed differences in the competitive success of North American-native and Eurasian-introduced P. australis genotypes, Eurasian-introduced P. australis would exhibit greater fitness in response to global change factors. Plasticity and plant performance to ambient and predicted levels of carbon dioxide and nitrogen pollution were investigated to understand how invasion pressure may change in North America under a realistic global change scenario. We found that the introduced Eurasian genotype expressed greater mean trait values in nearly every ecophysiological trait measured – aboveground and belowground – to elevated CO2 and nitrogen, outperforming the native North American conspecific by a factor of two to three under every global change scenario. This response is consistent with “jack and master” phenotypic plasticity. We suggest that differences in plant nitrogen productivity, specific leaf area, belowground biomass allocation, and inherently higher relative growth rate are the plant traits that may enhance invasion of Eurasian Phragmites in North America. Given the high degree of genotypic variability within this species, and our limited number of genotypes, our results must be interpreted cautiously. Our study is the first to demonstrate the potential importance of jack-and-master phenotypic plasticity in plant invasions when facing imminent global change conditions. We suggest that jack-and-master invasive genotypes and/or species similar to introduced P. australis will have an increased ecological fitness, facilitating their invasion in both stressful and resource rich environments.
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Affiliation(s)
- Thomas J Mozdzer
- Smithsonian Environmental Research Center, Edgewater, Maryland, United States of America.
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38
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Yan CF, Han SJ, Zhou YM, Wang CG, Dai GH, Xiao WF, Li MH. Needle-age related variability in nitrogen, mobile carbohydrates, and δ13C within Pinus koraiensis tree crowns. PLoS One 2012; 7:e35076. [PMID: 22493732 PMCID: PMC3320863 DOI: 10.1371/journal.pone.0035076] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 03/12/2012] [Indexed: 11/19/2022] Open
Abstract
For both ecologists and physiologists, foliar physioecology as a function of spatially and temporally variable environmental factors such as sunlight exposure within a tree crown is important for understanding whole tree physiology and for predicting ecosystem carbon balance and productivity. Hence, we studied concentrations of nitrogen (N), non-structural carbohydrates (NSC = soluble sugars + starch), and δ(13)C in different-aged needles within Pinus koraiensis tree crowns, to understand the needle age- and crown position-related physiology, in order to test the hypothesis that concentrations of N, NSC, and δ(13)C are needle-age and crown position dependent (more light, more photosynthesis affecting N, NSC, and δ(13)C), and to develop an accurate sampling strategy. The present study indicated that the 1-yr-old needles had significantly higher concentration levels of mobile carbohydrates (both on a mass and an area basis) and N(area) (on an area basis), as well as NSC-N ratios, but significantly lower levels of N(mass) (on a mass basis) concentration and specific leaf area (SLA), compared to the current-year needles. Azimuthal (south-facing vs. north-facing crown side) effects were found to be significant on starch [both on a mass (ST(mass)) and an area basis (ST(area))], δ(13)C values, and N(area), with higher levels in needles on the S-facing crown side than the N-facing crown side. Needle N(mass) concentrations significantly decreased but needle ST(mass), ST(area), and δ(13)C values significantly increased with increasing vertical crown levels. Our results suggest that the sun-exposed crown position related to photosynthetic activity and water availability affects starch accumulation and carbon isotope discrimination. Needle age associated with physiological activity plays an important role in determining carbon and nitrogen physiology. The present study indicates that across-scale sampling needs to carefully select tissue samples with equal age from a comparable crown position.
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Affiliation(s)
- Cai-Feng Yan
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Shi-Jie Han
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Yu-Mei Zhou
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Cun-Guo Wang
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Guan-Hua Dai
- Research Station of Changbai Moutain Forest Ecosystems, Chinese Academy of Sciences, Erdaobaihe, China
| | - Wen-Fa Xiao
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration, Chinese Academy of Forestry, Beijing, China
| | - Mai-He Li
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- Tree Physioecology, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
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Gough L, Gross KL, Cleland EE, Clark CM, Collins SL, Fargione JE, Pennings SC, Suding KN. Incorporating clonal growth form clarifies the role of plant height in response to nitrogen addition. Oecologia 2012; 169:1053-62. [PMID: 22302512 DOI: 10.1007/s00442-012-2264-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 01/15/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Gough
- Department of Biology, University of Texas at Arlington, Box 19498, Arlington, TX 76019, USA.
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40
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Benno P, Dahlgren AL, Midtvedt T. [Helicobacter pylori--a friend in need]. Lakartidningen 2011; 108:2232. [PMID: 22165187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Peter Benno
- institutionen for mikrobiologi, tumör- och cellbiologi (MTC), Karolinska institutet, Stockholm.
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Cabrera-Bosquet L, Albrizio R, Nogués S, Araus JL. Dual Δ¹³C/δ¹⁸O response to water and nitrogen availability and its relationship with yield in field-grown durum wheat. Plant Cell Environ 2011; 34:418-33. [PMID: 21062317 DOI: 10.1111/j.1365-3040.2010.02252.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The combined use of stable carbon and oxygen isotopes in plant matter is a tool of growing interest in cereal crop management and breeding, owing to its relevance for assessing the photosynthetic and transpirative performance under different growing conditions including water and N regimes. However, this method has not been applied to wheat grown under real field conditions. Here, plant growth, grain yield (GY) and the associated agronomic components, carbon isotope discrimination (Δ¹³C) plus oxygen isotope composition (δ¹⁸O) as well as leaf and canopy gas exchange were measured in field-grown wheat subjected to different water and N availabilities. Water limitation was the main factor affecting yield, leaf and canopy gas exchange and Δ¹³C and δ¹⁸O, whereas N had a smaller effect on such traits. The combination of Δ¹³C and δ¹⁸O gave a clear advantage compared with gas exchange measurements, as it provides information on the instantaneous and the long-term plant photosynthetic and transpirative performance and are less labour intensive than gas exchange measurements. In addition, the combination of plant Δ¹³C and δ¹⁸O predicted differences in GY and related agronomical parameters, providing agronomists and breeders with integrative traits for selecting crop management practices and/or genotypes with better performance under water-limiting and N-limiting conditions.
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Affiliation(s)
- Llorenç Cabrera-Bosquet
- Unitat de Fisiologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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42
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Ren H, Xu Z, Huang J, Clark C, Chen S, Han X. Nitrogen and water addition reduce leaf longevity of steppe species. Ann Bot 2011; 107:145-55. [PMID: 21084404 PMCID: PMC3002476 DOI: 10.1093/aob/mcq219] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 09/30/2010] [Accepted: 10/04/2010] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Changes in supplies of resources will modify plant functional traits. However, few experimental studies have addressed the effects of nitrogen and water variations, either singly or in combination, on functional traits. METHODS A 2-year field experiment was conducted to test the effects of nitrogen and water addition on leaf longevity and other functional traits of the two dominant (Agropyron cristatum and Stipa krylovii) and three most common species (Cleistogenes squarrosa, Melilotoides ruthenica and Potentilla tanacetifolia) in a temperate steppe in northern China. KEY RESULTS Additional nitrogen and water increased leaf nitrogen content and net photosynthetic rate, and changed other measured functional traits. Leaf longevity decreased significantly with both nitrogen addition (-6 days in 2007 and -5·4 days in 2008; both P < 0·001) and watering (-13 days in 2007 and -9·9 days in 2008; both P < 0·001), and significant differences in leaf longevity were also found among species. Nitrogen and water interacted to affect leaf longevity and other functional traits. Soil water content explained approx. 70 % of the shifts in leaf longevity. Biomass at both species and community level increased under water and nitrogen addition because of the increase in leaf biomass production per individual plant. CONCLUSIONS The results suggest that additional nitrogen and water supplies reduce plant leaf longevity. Soil water availability might play a fundamental role in determining leaf longevity and other leaf functional traits, and its effects can be modified by soil nitrogen availability in semi-arid areas. The different responses of species to resource alterations may cause different global change ramifications under future climate change scenarios.
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Affiliation(s)
- Haiyan Ren
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
- Graduate University of the Chinese Academy of Sciences, Yuquanlu, Beijing 100049, China
| | - Zhuwen Xu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Jianhui Huang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
| | - Christopher Clark
- School of Life Sciences and Global Institute of Sustainability, Arizona State University, Tempe, AZ 85287–4501, USA
| | - Shiping Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
| | - Xingguo Han
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
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Reumann S, Voitsekhovskaja O, Lillo C. From signal transduction to autophagy of plant cell organelles: lessons from yeast and mammals and plant-specific features. Protoplasma 2010; 247:233-56. [PMID: 20734094 DOI: 10.1007/s00709-010-0190-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Accepted: 07/28/2010] [Indexed: 05/08/2023]
Abstract
Autophagy is an evolutionarily conserved intracellular process for the vacuolar degradation of cytoplasmic constituents. The central structures of this pathway are newly formed double-membrane vesicles (autophagosomes) that deliver excess or damaged cell components into the vacuole or lysosome for proteolytic degradation and monomer recycling. Cellular remodeling by autophagy allows organisms to survive extensive phases of nutrient starvation and exposure to abiotic and biotic stress. Autophagy was initially studied by electron microscopy in diverse organisms, followed by molecular and genetic analyses first in yeast and subsequently in mammals and plants. Experimental data demonstrate that the basic principles, mechanisms, and components characterized in yeast are conserved in mammals and plants to a large extent. However, distinct autophagy pathways appear to differ between kingdoms. Even though direct information remains scarce particularly for plants, the picture is emerging that the signal transduction cascades triggering autophagy and the mechanisms of organelle turnover evolved further in higher eukaryotes for optimization of nutrient recycling. Here, we summarize new research data on nitrogen starvation-induced signal transduction and organelle autophagy and integrate this knowledge into plant physiology.
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Affiliation(s)
- Sigrun Reumann
- Centre for Organelle Research, University of Stavanger, 4021 Stavanger, Norway.
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Szalai G, Dai N, Danin A, Dudai N, Barazani O. Effect of nitrogen source in the fertilizing solution on nutritional quality of three members of the Portulaca oleracea aggregate. J Sci Food Agric 2010; 90:2039-2045. [PMID: 20572061 DOI: 10.1002/jsfa.4049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Portulaca oleracea (purslane) is nutritious but, in addition to the essential alpha-linolenic acid, vitamin C and tocopherols, it contains undesirable oxalic acid. Knowing the effects of nitrate and ammonium on oxalate accumulation, we tested the agronomic potential of three members of the P. oleracea aggregate under various nitrogen fertilization conditions, by measuring biomass production and accumulation of fatty acids, organic acids and tocopherol in the commercial P. sativa (Pos) and two natural members: P. nitida (Pon) and P. papillato-stellulata (Pop). RESULTS With nitrate as the sole N source, we measured differences between Pon and Pos in concentrations of the essential omega-3 fatty acid alpha-linolenic acid. Pos also gained less dry biomass under these conditions, implying a higher agronomical and nutritional value for Pon. Increasing the fertilizer ammonium concentration and reducing that of nitrate significantly decreased oxalic acid by factors of up to 1.7, 2.6 and 3.4 in Pos, Pop and Pon, respectively, significantly increased concentrations of tocopherol and malic acid, had no effect on fatty acids or ascorbic acid, but reduced biomass. CONCLUSION In spite of the recumbent growth habit of Pon, the present findings indicate its agronomic potential. Because early flowering and seed production may be the limiting factors in purslane agriculture, growing Pon in nitrate-poor conditions might be agriculturally favorable.
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Affiliation(s)
- Gabriella Szalai
- Agricultural Research Institute of the Hungarian Academy of Sciences, H-2462 Martonvasar, Hungary
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McCarthy HR, Oren R, Johnsen KH, Gallet-Budynek A, Pritchard SG, Cook CW, Ladeau SL, Jackson RB, Finzi AC. Re-assessment of plant carbon dynamics at the Duke free-air CO(2) enrichment site: interactions of atmospheric [CO(2)] with nitrogen and water availability over stand development. New Phytol 2010; 185:514-28. [PMID: 19895671 DOI: 10.1111/j.1469-8137.2009.03078.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
*The potential for elevated [CO(2)]-induced changes to plant carbon (C) storage, through modifications in plant production and allocation of C among plant pools, is an important source of uncertainty when predicting future forest function. Utilizing 10 yr of data from the Duke free-air CO(2) enrichment site, we evaluated the dynamics and distribution of plant C. *Discrepancy between heights measured for this study and previously calculated heights required revision of earlier allometrically based biomass determinations, resulting in higher (up to 50%) estimates of standing biomass and net primary productivity than previous assessments. *Generally, elevated [CO(2)] caused sustained increases in plant biomass production and in standing C, but did not affect the partitioning of C among plant biomass pools. Spatial variation in net primary productivity and its [CO(2)]-induced enhancement was controlled primarily by N availability, with the difference between precipitation and potential evapotranspiration explaining most interannual variability. Consequently, [CO(2)]-induced net primary productivity enhancement ranged from 22 to 30% in different plots and years. *Through quantifying the effects of nutrient and water availability on the forest productivity response to elevated [CO(2)], we show that net primary productivity enhancement by elevated [CO(2)] is not uniform, but rather highly dependent on the availability of other growth resources.
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Affiliation(s)
- Heather R McCarthy
- Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC 27708, USA.
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Abdul-Hamid H, Mencuccini M. Age- and size-related changes in physiological characteristics and chemical composition of Acer pseudoplatanus and Fraxinus excelsior trees. Tree Physiol 2009; 29:27-38. [PMID: 19203930 DOI: 10.1093/treephys/tpn001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Forest growth is an important factor both economically and ecologically, and it follows a predictable trend with age. Generally, growth accelerates as canopies develop in young forests and declines substantially soon after maximum leaf area is attained. The causes of this decline are multiple and may be linked to age- or size-related processes, or both. Our objective was to determine the relative effects of tree age and tree size on the physiological attributes of two broadleaf species. As age and size are normally coupled during growth, an approach based on grafting techniques to separate the effects of size from those of age was adopted. Genetically identical grafted seedlings were produced from scions taken from trees of four age classes, ranging from 4 to 162 years. We found that leaf-level net photosynthetic rate per unit of leaf mass and some other leaf structural and biochemical characteristics had decreased substantially with increasing size of the donor trees in the field, whereas other gas exchange parameters expressed on a leaf area basis did not. In contrast, these parameters remained almost constant in grafted seedlings, i.e., scions taken from donor trees with different meristematic ages show no age-related trend after they were grafted onto young rootstocks. In general, the results suggested that size-related limitations triggered the declines in photosynthate production and tree growth, whereas less evidence was found to support a role of meristematic age.
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Affiliation(s)
- Hazandy Abdul-Hamid
- Department of Forest Production, Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
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Abstract
Lawns are a dominant cover type in urban ecosystems, and there is concern about their impacts on water quality. However, recent watershed-level studies suggest that these pervious areas might be net sinks, rather than sources, for nitrogen (N) in the urban environment. A 15N pulse-labeling experiment was performed on lawn and forest plots in the Baltimore (Maryland, U.S.A.) metropolitan area to test the hypothesis that lawns are a net sink for atmospheric-N deposition and to compare and contrast mechanisms of N retention in these vegetation types. A pulse of 15N-NO3-, simulating a precipitation event, was followed through mineral soils, roots, Oi-layer/thatch, aboveground biomass, microbial biomass, inorganic N, and evolved N2 gas over a one-year period. The 15N label was undetectable in gaseous samples, but enrichment of other pools was high. Gross rates of production and consumption of NO3- and NH4+ were measured to assess differences in internal N cycling under lawns and forests. Rates of N retention were similar during the first five days of the experiment, with lawns showing higher N retention than forests after 10, 70, and 365 days. Lawns had larger pools of available NO3- and NH4+; however, gross rates of mineralization and nitrification were also higher, leading to no net differences in NO3- and NH4+ turnover times between the two systems. Levels of 15N remained steady in forest mineral soils from day 70 to 365 (at 23% of applied 15N), but continued to accumulate in lawn mineral soils over this same time period, increasing from 20% to 33% of applied 15N. The dominant sink for N in lawn plots changed over time. Immobilization in mineral soils dominated immediately (one day) after tracer application (42% of recovered 15N); plant biomass dominated the short term (10 days; 51%); thatch and mineral-soil pools together dominated the medium term (70 days; 28% and 36%, respectively); and the mineral-soil pool alone dominated long-term retention (one year; 70% of recovered 15N). These findings illustrate the mechanisms whereby urban and suburban lawns under low to moderate management intensities are an important sink for atmospheric-N deposition.
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Affiliation(s)
- S M Raciti
- Department of Natural Resources, Cornell University, Fernow Hall, Ithaca, New York 14853, USA.
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Kier LB. A review of recent studies relating ligand diffusion, general anesthesia, and sleep. AANA J 2008; 76:109-112. [PMID: 18478815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This review article presents 3 theories related to ligand diffusion, general anesthesia and sleep. The first theory describes the diffusion of molecules across a protein surface to a receptor. It is based on the effect of the amino acid side chains on the protein surface on the structure of bulk water nearby. This influence creates pathways, called chreodes, through the water near the protein surface, permitting a rapid diffusion of molecules to the receptors. A second theory involving the role of chreodes presents a mechanism of action of nonspecific anesthetic agents. These agents interrupt the diffusion of neurotransmitter molecules to their receptors, bringing on the anesthetic effects. Finally, building on the similarities of anesthesia and sleep, a theory is presented proposing that an external agent influences sleep in a way similar to that of the nonspecific anesthetic molecules. This external agent is proposed to be elemental nitrogen. Several observations are presented to support this mechanism.
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Affiliation(s)
- Lemont B Kier
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, USA.
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McNeil BE, Read JM, Sullivan TJ, McDonnell TC, Fernandez IJ, Driscoll CT. The spatial pattern of nitrogen cycling in the Adirondack Park, New York. Ecol Appl 2008; 18:438-452. [PMID: 18488607 DOI: 10.1890/07-0276.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Maps of canopy nitrogen obtained through analysis of high-resolution, hyperspectral, remotely sensed images now offer a powerful means to make landscape-scale to regional-scale estimates of forest N cycling and net primary production (NPP). Moreover, recent research has suggested that the spatial variability within maps of canopy N may be driven by environmental gradients in such features as historic forest disturbance, temperature, species composition, moisture, geology, and atmospheric N deposition. Using the wide variation in these six features found within the diverse forest ecosystems of the 2.5 million ha Adirondack Park, New York, USA, we examined linkages among environmental gradients and three measures of N cycling collected during the 2003 growing season: (1) field survey of canopy N, (2) field survey of soil C:N, and (3) canopy N measured through analysis of two 185 x 7.5 km Hyperion hyperspectral images. These three measures of N cycling strongly related to forest type but related poorly to all other environmental gradients. Further analysis revealed that the spatial pattern in N cycling appears to have distinct inter- and intraspecific components of variability. The interspecific component, or the proportional contribution of species functional traits to canopy biomass, explained 93% of spatial variability within the field canopy N survey and 37% of variability within the soil C:N survey. Residual analysis revealed that N deposition accounted for an additional 2% of variability in soil C:N, and N deposition and historical forest disturbance accounted for an additional 2.8% of variability in canopy N. Given our finding that 95.8% of the variability in the field canopy N survey could be attributed to variation in the physical environment, our research suggests that remotely sensed maps of canopy N may be useful not only to assess the spatial variability in N cycling and NPP, but also to unravel the relative importance of their multiple controlling factors.
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Affiliation(s)
- Brenden E McNeil
- Department of Geography, Maxwell School of Citizenship and Public Affairs, Syracuse University, Syracuse, New York 13244, USA.
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Gunter SA, Beck PA, Hutchison S, Phillips JM. Effects of stocking and nitrogen fertilization rates on steers grazing dallisgrass-dominated pasture. J Anim Sci 2008; 83:2235-42. [PMID: 16100079 DOI: 10.2527/2005.8392235x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To compare the performance of steer calves managed under different stocking rates (SR; 3.7, 6.2, 8.6, and 11.1 steers/ha for 140 d; chi(I1)) and N fertilization rates (112, 224, and 336 kg of N/ha; chi(I2)) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 +/- 2.5 kg) were assigned randomly to one of 12 0.81-ha dallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: gammai = beta0 + beta1chi(I1) + beta2chi(I2) + beta(11)chi2(I1) + beta(12)chi2(I2) + beta(12)chi(i1)chi(i2) + epsilonI, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and returned 355.64 dollars. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112, 224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually.
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Affiliation(s)
- S A Gunter
- Southwest Research and Extension Center, Division of Agriculture, University of Arkansas, Hope, 71801, USA.
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