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Nie Z, Wang L, Zhao P, Wang Z, Shi Q, Liu H. Metabolomics reveals the impact of nitrogen combined with the zinc supply on zinc availability in calcareous soil via root exudates of winter wheat (Triticum aestivum). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 204:108069. [PMID: 37852066 DOI: 10.1016/j.plaphy.2023.108069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/20/2023]
Abstract
A possible mechanism for the improved availability of zinc (Zn) in soil by combining nitrogen (N) with Zn supply was investigated based on the root exudates of winter wheat. N, Zn supply as well as their combination significantly regulated nine root exudates in winter wheat; in which, the secretion of cis-aconitic acid involving in the TCA cycle, C5-branched dibasic acid metabolism, glyoxylate and dicarboxylate metabolism and 2-oxocarboxylic acid metabolism was upregulated by N, Zn supply as well as their combination. N-Zn combination induced the activities of citrate synthase and cis-aconitase in roots and shoots of winter wheat thus to increase the concentrations of citric and aconitic acid; the decrease of isocitric acid concentrations in shoots indicated the inhibited conversion of aconitic acid to isocitric acid by N-Zn combination. It revealed a possible reason for the enhanced secretion of cis-aconitic acid by N-Zn combination. Exogenous addition of 10 μ plant-1 cis-aconitate significantly increased available Zn concentrations in soil and Zn concentrations in winter wheat under N-Zn combination. Thus, the N-Zn combination regulated the metabolism of cis-aconitic acid in winter wheat, thus enhancing the secretion of cis-aconitic acid to increase the bioavailability of Zn in soil.
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Affiliation(s)
- Zhaojun Nie
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
| | - Linglu Wang
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
| | - Peng Zhao
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
| | - Zhenbo Wang
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
| | - Qiuzhe Shi
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
| | - Hongen Liu
- Resources and Environment College, Henan Agricultural University, Zhengzhou, 450002, Henan Province, China.
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Bělonožníková K, Černý M, Hýsková V, Synková H, Valcke R, Hodek O, Křížek T, Kavan D, Vaňková R, Dobrev P, Haisel D, Ryšlavá H. Casein as protein and hydrolysate: Biostimulant or nitrogen source for Nicotiana tabacum plants grown in vitro? PHYSIOLOGIA PLANTARUM 2023; 175:e13973. [PMID: 37402155 DOI: 10.1111/ppl.13973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/28/2023] [Accepted: 06/28/2023] [Indexed: 07/06/2023]
Abstract
In contrast to inorganic nitrogen (N) assimilation, the role of organic N forms, such as proteins and peptides, as sources of N and their impact on plant metabolism remains unclear. Simultaneously, organic biostimulants are used as priming agents to improve plant defense response. Here, we analysed the metabolic response of tobacco plants grown in vitro with casein hydrolysate or protein. As the sole source of N, casein hydrolysate enabled tobacco growth, while protein casein was used only to a limited extent. Free amino acids were detected in the roots of tobacco plants grown with protein casein but not in the plants grown with no source of N. Combining hydrolysate with inorganic N had beneficial effects on growth, root N uptake and protein content. The metabolism of casein-supplemented plants shifted to aromatic (Trp), branched-chain (Ile, Leu, Val) and basic (Arg, His, Lys) amino acids, suggesting their preferential uptake and/or alterations in their metabolic pathways. Complementarily, proteomic analysis of tobacco roots identified peptidase C1A and peptidase S10 families as potential key players in casein degradation and response to N starvation. Moreover, amidases were significantly upregulated, most likely for their role in ammonia release and impact on auxin synthesis. In phytohormonal analysis, both forms of casein influenced phenylacetic acid and cytokinin contents, suggesting a root system response to scarce N availability. In turn, metabolomics highlighted the stimulation of some plant defense mechanisms under such growth conditions, that is, the high concentrations of secondary metabolites (e.g., ferulic acid) and heat shock proteins.
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Affiliation(s)
- Kateřina Bělonožníková
- Department of Biochemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
| | - Martin Černý
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Veronika Hýsková
- Department of Biochemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
| | - Helena Synková
- Institute of Experimental Botany, Czech Academy of Sciences, Praha 6, Czech Republic
| | - Roland Valcke
- Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Diepenbeek, Belgium
| | - Ondřej Hodek
- Department of Analytical Chemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
| | - Tomáš Křížek
- Department of Analytical Chemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
| | - Daniel Kavan
- Department of Biochemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
| | - Radomíra Vaňková
- Institute of Experimental Botany, Czech Academy of Sciences, Praha 6, Czech Republic
| | - Petre Dobrev
- Institute of Experimental Botany, Czech Academy of Sciences, Praha 6, Czech Republic
| | - Daniel Haisel
- Institute of Experimental Botany, Czech Academy of Sciences, Praha 6, Czech Republic
| | - Helena Ryšlavá
- Department of Biochemistry, Faculty of Science, Charles University, Praha 2, Czech Republic
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Adamczyk B. Root-Derived Proteases as a Plant Tool to Access Soil Organic Nitrogen; Current Stage of Knowledge and Controversies. PLANTS 2021; 10:plants10040731. [PMID: 33918076 PMCID: PMC8069566 DOI: 10.3390/plants10040731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/30/2021] [Accepted: 04/07/2021] [Indexed: 02/03/2023]
Abstract
Anthropogenic deterioration of the global nitrogen (N) cycle emerges mainly from overuse of inorganic N fertilizers in nutrient-limited cropping systems. To counteract a further dysregulation of the N cycle, we need to improve plant nitrogen use efficiency. This aim may be reached via unravelling all plant mechanisms to access soil N, with special attention to the dominating high-molecular-mass N pool. Traditionally, we believe that inorganic N is the only plant-available N pool, however, more recent studies point to acquisition of organic N compounds, i.e., amino acids, short peptides, and proteins. The least known mechanism of plants to increase the N uptake is a direct increase of soil proteolysis via root-derived proteases. This paper provides a review of the knowledge about root-derived proteases and also controversies behind this phenomenon.
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Affiliation(s)
- Bartosz Adamczyk
- The Natural Resources Institute, Luonnonvarakeskus, Viikinkaari 4, 00790 Helsinki, Finland
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4
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Arai N, Ohno Y, Jumyo S, Hamaji Y, Ohyama T. Organ-specific expression and epigenetic traits of genes encoding digestive enzymes in the lance-leaf sundew (Drosera adelae). JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1946-1961. [PMID: 33247920 PMCID: PMC7921302 DOI: 10.1093/jxb/eraa560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 11/25/2020] [Indexed: 05/16/2023]
Abstract
Over the last two decades, extensive studies have been performed at the molecular level to understand the evolution of carnivorous plants. As fruits, the repertoire of protein components in the digestive fluids of several carnivorous plants have gradually become clear. However, the quantitative aspects of these proteins and the expression mechanisms of the genes that encode them are still poorly understood. In this study, using the Australian sundew Drosera adelae, we identified and quantified the digestive fluid proteins. We examined the expression and methylation status of the genes corresponding to major hydrolytic enzymes in various organs; these included thaumatin-like protein, S-like RNase, cysteine protease, class I chitinase, β-1, 3-glucanase, and hevein-like protein. The genes encoding these proteins were exclusively expressed in the glandular tentacles. Furthermore, the promoters of the β-1, 3-glucanase and cysteine protease genes were demethylated only in the glandular tentacles, similar to the previously reported case of the S-like RNase gene da-I. This phenomenon correlated with high expression of the DNA demethylase DEMETER in the glandular tentacles, strongly suggesting that it performs glandular tentacle-specific demethylation of the genes. The current study strengthens and generalizes the relevance of epigenetics to trap organ-specific gene expression in D. adelae. We also suggest similarities between the trap organs of carnivorous plants and the roots of non-carnivorous plants.
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Affiliation(s)
- Naoki Arai
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Yusuke Ohno
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Shinya Jumyo
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Yusuke Hamaji
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Takashi Ohyama
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Shinjuku-ku, Tokyo, Japan
- Correspondence:
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Greenfield LM, Hill PW, Paterson E, Baggs EM, Jones DL. Do plants use root-derived proteases to promote the uptake of soil organic nitrogen? PLANT AND SOIL 2020; 456:355-367. [PMID: 33087989 PMCID: PMC7567722 DOI: 10.1007/s11104-020-04719-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
AIMS The capacity of plant roots to directly acquire organic nitrogen (N) in the form of oligopeptides and amino acids from soil is well established. However, plants have poor access to protein, the central reservoir of soil organic N. Our question is: do plants actively secrete proteases to enhance the breakdown of soil protein or are they functionally reliant on soil microorganisms to undertake this role? METHODS Growing maize and wheat under sterile hydroponic conditions with and without inorganic N, we measured protease activity on the root surface (root-bound proteases) or exogenously in the solution (free proteases). We compared root protease activities to the rhizosphere microbial community to estimate the ecological significance of root-derived proteases. RESULTS We found little evidence for the secretion of free proteases, with almost all protease activity associated with the root surface. Root protease activity was not stimulated under N deficiency. Our findings suggest that cereal roots contribute one-fifth of rhizosphere protease activity. CONCLUSIONS Our results indicate that plant N uptake is only functionally significant when soil protein is in direct contact with root surfaces. The lack of protease upregulation under N deficiency suggests that root protease activity is unrelated to enhanced soil N capture.
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Affiliation(s)
| | - Paul W. Hill
- School of Natural Sciences, Bangor University, Gwynedd, LL57 2UW UK
| | - Eric Paterson
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH UK
| | - Elizabeth M. Baggs
- Global Academy of Agriculture and Food Security, the Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG UK
| | - Davey L. Jones
- School of Natural Sciences, Bangor University, Gwynedd, LL57 2UW UK
- SoilsWest, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
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6
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Noll L, Zhang S, Zheng Q, Hu Y, Wanek W. Wide-spread limitation of soil organic nitrogen transformations by substrate availability and not by extracellular enzyme content. SOIL BIOLOGY & BIOCHEMISTRY 2019; 133:37-49. [PMID: 31579313 PMCID: PMC6774789 DOI: 10.1016/j.soilbio.2019.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Proteins constitute the single largest soil organic nitrogen (SON) reservoir and its decomposition drives terrestrial N availability. Protein cleavage by extracellular enzymes is the rate limiting step in the soil organic N cycle and can be controlled by extracellular enzyme production or protein availability/stabilization in soil. Both controls can be affected by geology and land use, as well as be vulnerable to changes in soil temperature and moisture/O2. To explore major controls of soil gross protein depolymerization we sampled six soils from two soil parent materials (calcareous and silicate), where each soil type included three land uses (cropland, pasture and forest). Soil samples were subjected to three temperature treatments (5, 15, 25 °C at 60% water-holding capacity (WHC) and aerobic conditions) or three soil moisture/O2 treatments (30 and 60% WHC at 21% O2, 90% WHC at 1% O2, at 20 °C) in short-term experiments. Samples were incubated for one day in the temperature experiment and for one week in the moisture/O2 experiment. Gross protein depolymerization rates were measured by a novel 15N isotope pool dilution approach. The low temperature sensitivity of gross protein depolymerization, the lack of relationship with protease activity and strong effects of soil texture and pH demonstrate that this process is constrained by organo-mineral associations and not by soil enzyme content. This also became apparent from the inverse effects in calcareous and silicate soils caused by water saturation/O2 limitation. We highlight that the specific soil mineralogy influenced the response of gross depolymerization rates to water saturation/O2 limitation, causing (I) increasing gross depolymerization rates due to release of adsorbed proteins by reductive dissolution of Fe- and Mn-oxyhydroxides in calcareous soils and (II) decreasing gross depolymerization rates due to mobilization of coagulating and toxic Al3+ compounds in silicate soils.
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Affiliation(s)
- Lisa Noll
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Shasha Zhang
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Qing Zheng
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Yuntao Hu
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Wolfgang Wanek
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
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7
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Kobylińska A, Borek S, Posmyk MM. Melatonin redirects carbohydrates metabolism during sugar starvation in plant cells. J Pineal Res 2018; 64:e12466. [PMID: 29292521 DOI: 10.1111/jpi.12466] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/21/2017] [Indexed: 12/25/2022]
Abstract
Recent studies have shown that melatonin is an important molecule in plant physiology. It seems that the most important is that melatonin efficacy eliminates oxidative stress (direct and indirect antioxidant) and moreover induce plant stress reaction and switch on different defence strategies (preventively and interventively actions). In this report, the impact of exogenous melatonin on carbohydrate metabolism in Nicotiana tabacum L. line Bright Yellow 2 (BY-2) suspension cells during sugar starvation was examined. We analysed starch concentration, α-amylase and PEPCK activity as well as proteolytic activity in culture media. It has been shown that BY-2 cell treatment with 200 nM of melatonin improved viability of sugar-starved cells. It was correlated with higher starch content and phosphoenolpyruvate carboxykinase (PEPCK) activity. The obtained results revealed that exogenous melatonin under specific conditions (stress) can play regulatory role in sugar metabolism, and it may modulate carbohydrate concentration in etiolated BY-2 cells. Moreover, our results confirmed the hypothesis that if the starch is synthesised even in sugar-starved cells, it is highly probable that melatonin shifts the BY-2 cell metabolism on gluconeogenesis pathway and allows for synthesis of carbohydrates from nonsugar precursors, that is amino acids. These points to another defence strategy that was induced by exogenous melatonin applied in plants to overcome adverse environmental conditions.
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Affiliation(s)
- Agnieszka Kobylińska
- Laboratory of Plant Ecophysiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Sławomir Borek
- Department of Plant Physiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - Małgorzata M Posmyk
- Laboratory of Plant Ecophysiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
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8
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Abstract
Chronic wasting disease (CWD) affects cervids and is the only known prion disease readily transmitted among free-ranging wild animal populations in nature. The increasing spread and prevalence of CWD among cervid populations threaten the survival of deer and elk herds in North America, and potentially beyond. This review focuses on prion ecology, specifically that of CWD, and the current understanding of the role that the environment may play in disease propagation. We recount the discovery of CWD, discuss the role of the environment in indirect CWD transmission, and consider potentially relevant environmental reservoirs and vectors. We conclude by discussing how understanding the environmental persistence of CWD lends insight into transmission dynamics and potential management and mitigation strategies.
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9
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Soares MA, Li HY, Kowalski KP, Bergen M, Torres MS, White JF. Functional Role of Bacteria from Invasive Phragmites australis in Promotion of Host Growth. MICROBIAL ECOLOGY 2016; 72:407-417. [PMID: 27260154 DOI: 10.1007/s00248-016-0793-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 05/18/2016] [Indexed: 06/05/2023]
Abstract
We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.
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Affiliation(s)
- M A Soares
- Department of Botany and Ecology, Federal University of Mato Grosso, Cuiabá, Mato Grosso, 78060-900, Brazil.
| | - H-Y Li
- Faculty of Life Sciences and Technology, Kunming University of Science and Technology, Kunming, 650500, Yunnan Province, China
| | - K P Kowalski
- US Geological Survey, Great Lakes Science Center, Ann Arbor, MI, USA
| | - M Bergen
- Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ, 08901-8520, USA
| | - M S Torres
- Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ, 08901-8520, USA
| | - J F White
- Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ, 08901-8520, USA
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10
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Rasmussen J, Gilroyed BH, Reuter T, Dudas S, Neumann NF, Balachandran A, Kav NNV, Graham C, Czub S, McAllister TA. Can plants serve as a vector for prions causing chronic wasting disease? Prion 2015; 8:136-42. [PMID: 24509640 DOI: 10.4161/pri.27963] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Prions, the causative agent of chronic wasting disease (CWD) enter the environment through shedding of bodily fluids and carcass decay, posing a disease risk as a result of their environmental persistence. Plants have the ability to take up large organic particles, including whole proteins, and microbes. This study used wheat (Triticum aestivum L.) to investigate the uptake of infectious CWD prions into roots and their transport into aerial tissues. The roots of intact wheat plants were exposed to infectious prions (PrP(TSE)) for 24 h in three replicate studies with PrP(TSE) in protein extracts being detected by western blot, IDEXX and Bio-Rad diagnostic tests. Recombinant prion protein (PrP(C)) bound to roots, but was not detected in the stem or leaves. Protease-digested CWD prions (PrP(TSE)) in elk brain homogenate interacted with root tissue, but were not detected in the stem. This suggests wheat was unable to transport sufficient PrP(TSE) from the roots to the stem to be detectable by the methods employed. Undigested PrP(TSE) did not associate with roots. The present study suggests that if prions are transported from the roots to the stems it is at levels that are below those that are detectable by western blot, IDEXX or Bio-Rad diagnostic kits.
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11
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White JF, Chen Q, Torres MS, Mattera R, Irizarry I, Tadych M, Bergen M. Collaboration between grass seedlings and rhizobacteria to scavenge organic nitrogen in soils. AOB PLANTS 2015; 7:plu093. [PMID: 25564515 PMCID: PMC4313791 DOI: 10.1093/aobpla/plu093] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 12/17/2014] [Indexed: 05/23/2023]
Abstract
Plants require nitrogen (N) to make proteins, nucleic acids and other biological molecules. It is widely accepted that plants absorb inorganic forms of N to fill their needs. However, recently it has become clear that plants also have the capacity to absorb organic N from soils. In this paper we describe a new kind of symbiosis involving seed-vectored rhizobacteria and grasses that is targeted at enhancing acquisition of organic N from soils. Our proposal is based on results of experiments on seedlings of grass species Festuca arundinacea Schreb., Lolium perenne L. and Poa annua L. that suggest: (i) seed-vectored rhizobacteria colonize seedling roots and influence their development; (ii) reactive oxygen secretion by seedling roots plays a role in organic N procurement by denaturing microbial proteins in the vicinity of roots (daytime activity); and (iii) plant root and microbial proteases degrade denatured proteins prior to absorption by roots (night-time activity). This research involved the following types of studies: (i) seedling root development experiments with and without rhizobacteria on a variety of substrates in agarose media and (ii) isotopic N-tracking experiments to evaluate the absorption into seedlings of N obtained from degradation of proteins. We hypothesize that grasses, in particular, are adapted to scavenge organic N from soils through application of this 'oxidative nitrogen scavenging' symbiosis with rhizobacteria, and their soil-permeating root systems. This newly discovered symbiosis in grass species could lead to new ways to cultivate and manage grasses to enhance efficiency of N utilization and reduce applications of inorganic fertilizers.
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Affiliation(s)
- James F White
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Qiang Chen
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Mónica S Torres
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Robert Mattera
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Ivelisse Irizarry
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Mariusz Tadych
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
| | - Marshall Bergen
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
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12
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Vinall K, Schmidt S, Brackin R, Lakshmanan P, Robinson N. Amino acids are a nitrogen source for sugarcane. FUNCTIONAL PLANT BIOLOGY : FPB 2012; 39:503-511. [PMID: 32480801 DOI: 10.1071/fp12042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 04/16/2012] [Indexed: 06/11/2023]
Abstract
Organic forms of nitrogen (ON) represent potential N sources for crops and an alternative to inorganic N (IN, ammonium nitrate). Sugarcane soils receive organic harvest residues (~40-100kg ON ha-1), but it is unknown whether ON is a direct N source for crops. We investigated whether sugarcane can use organic monomers in the form of amino acids and whether the use of amino acids as a N source results in distinct metabolic or morphological change when compared with use of inorganic N (IN). Plantlets cultivated in sterile culture and young plants grown in non-sterile soil culture were supplied with IN, ON (five amino acids present in sugarcane soils), or combined IN and ON. All treatments resulted in similar biomass and N content indicating that sugarcane has a well developed capacity to use ON and confirms findings in other species. ON-supplied plants in axenic culture had increased total branch root length per unit primary root axis which has not been reported previously. In both experimental systems, ON supplied plants had increased asparagine concentrations suggesting altered N metabolism. Root of ON-supplied soil-grown plants had significantly reduced nitrate concentrations. We interpret the shift from nitrate to asparagine as indicative of N form use other than or in addition to nitrate by sugarcane. N metabolite profiling could advance knowledge of crop N sources and this will aid in development of N efficient cropping systems with a reduced N pollution footprint.
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Affiliation(s)
- Kerry Vinall
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Susanne Schmidt
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Richard Brackin
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Qld 4072, Australia
| | | | - Nicole Robinson
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Qld 4072, Australia
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13
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Kohli A, Narciso JO, Miro B, Raorane M. Root proteases: reinforced links between nitrogen uptake and mobilization and drought tolerance. PHYSIOLOGIA PLANTARUM 2012; 145:165-79. [PMID: 22242864 DOI: 10.1111/j.1399-3054.2012.01573.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Integral subcellular and cellular functions ranging from gene expression, protein targeting and nutrient supply to cell differentiation and cell death require proteases. Plants have unique organelles such as chloroplasts composed of unique proteins that carry out the unique process of photosynthesis. Hence, along with proteases common across kingdoms, plants contain unique proteases. Improved knowledge on proteases can lead to a better understanding of plant development, differentiation and death. Because of their importance in multiple processes, plant proteases are actively studied. However, root proteases specifically are not as well studied. The associated rhizosphere, organic matter and/or inorganic matter make roots a difficult system. Yet recent research conclusively demonstrated the occurrence of endocytosis of proteins, peptides and even microbes by root cells, which, hitherto known for specialized pathogenesis or symbiosis, was unsuspected for nutrient uptake. These results reinforced the importance of root proteases in endocytosis or root exudate-mediated nutrient uptake. Rhizoplane, rhizosphere or in planta protease action on proteins, peptides and microbes generates sources of nitrogen, especially during abiotic stresses such as drought. This article highlights the recent research on root proteases for nitrogen uptake and the connection of the two to drought-tolerance mechanisms. Drought-induced proteases in rice roots, as known from rice expression databases, are discussed for future research on certain M50, Deg, FtsH, AMSH and deubiquitination proteases. The recent emphasis on linking drought and plant hydraulics to nutrient metabolism is illustrated and connected to the value of a systematic study of root proteases in crop improvement.
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Affiliation(s)
- Ajay Kohli
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, DAPO, Metro Manila, Philippines.
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Soper FM, Paungfoo-Lonhienne C, Brackin R, Rentsch D, Schmidt S, Robinson N. Arabidopsis and Lobelia anceps access small peptides as a nitrogen source for growth. FUNCTIONAL PLANT BIOLOGY : FPB 2011; 38:788-796. [PMID: 32480936 DOI: 10.1071/fp11077] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 07/21/2011] [Indexed: 05/09/2023]
Abstract
While importance of amino acids as a nitrogen source for plants is increasingly recognised, other organic N sources including small peptides have received less attention. We assessed the capacity of functionally different species, annual and nonmycorrhizal Arabidopsis thaliana (L.) Heynh. (Brassicaceae) and perennial Lobelia anceps L.f. (Campanulaceae), to acquire, metabolise and use small peptides as a N source independent of symbionts. Plants were grown axenically on media supplemented with small peptides (2-4 amino acids), amino acids or inorganic N. In A. thaliana, peptides of up to four amino acid residues sustained growth and supported up to 74% of the maximum biomass accumulation achieved with inorganic N. Peptides also supported growth of L. anceps, but to a lesser extent. Using metabolite analysis, a proportion of the peptides supplied in the medium were detected intact in root and shoot tissue together with their metabolic products. Nitrogen source preferences, growth responses and shoot-root biomass allocation were species-specific and suggest caution in the use of Arabidopsis as the sole plant model. In particular, glycine peptides of increasing length induced effects ranging from complete inhibition to marked stimulation of root growth. This study contributes to emerging evidence that plants can acquire and metabolise organic N beyond amino acids.
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Affiliation(s)
- Fiona M Soper
- School of Agriculture and Food Science, University of Queensland, St Lucia, Qld 4072, Australia
| | | | - Richard Brackin
- School of Agriculture and Food Science, University of Queensland, St Lucia, Qld 4072, Australia
| | - Doris Rentsch
- Molecular Plant Physiology, Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland
| | - Susanne Schmidt
- School of Agriculture and Food Science, University of Queensland, St Lucia, Qld 4072, Australia
| | - Nicole Robinson
- School of Agriculture and Food Science, University of Queensland, St Lucia, Qld 4072, Australia
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Adamczyk B, Smolander A, Kitunen V, Godlewski M. Proteins as nitrogen source for plants: a short story about exudation of proteases by plant roots. PLANT SIGNALING & BEHAVIOR 2010; 5:817-9. [PMID: 20505350 PMCID: PMC3014533 DOI: 10.4161/psb.5.7.11699] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Interest in the problem of plant nitrogen nutrition is increasing. Certain plants can use not only inorganic nitrogen, but also intact amino acids and short peptides. According to our studies, the roots of several agricultural and wild-living plants are able to exude proteases and by using them to create a pool of accessible N. This mini-review offers an overview of the problem of protease exudation by plant roots and its potential role in plant nitrogen nutrition.
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Affiliation(s)
- Bartosz Adamczyk
- Finnish Forest Research Institute, Vantaa Research Centre, Vantaa, Finland.
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Adamczyk B, Godlewski M, Smolander A, Kitunen V. Degradation of proteins by enzymes exuded by Allium porrum roots - a potentially important strategy for acquiring organic nitrogen by plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:919-925. [PMID: 19540770 DOI: 10.1016/j.plaphy.2009.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 05/31/2009] [Indexed: 05/27/2023]
Abstract
Nitrogen is one of the crucial elements that regulate plant growth and development. It is well-established that plants can acquire nitrogen from soil in the form of low-molecular-mass compounds, namely nitrate and ammonium, but also as amino acids. Nevertheless, nitrogen in the soil occurs mainly as proteins or proteins complexed with other organic compounds. Proteins are believed not to be available to plants. However, there is increasing evidence to suggest that plants can actively participate in proteolysis by exudation of proteases by roots and can obtain nitrogen from digested proteins. To gain insight into the process of organic nitrogen acquisition from proteins by leek roots (Allium porrum L. cv. Bartek), casein, bovine serum albumin and oxidized B-chain of insulin were used; their degradation products, after exposure to plant culture medium, were studied using liquid chromatography-mass spectrometry (LC-MS). Casein was degraded to a great extent, but the level of degradation of bovine serum albumin and the B-chain of insulin was lower. Proteases exuded by roots cleaved proteins, releasing low-molecular-mass peptides that can be taken up by roots. Various peptide fragments produced by digestion of the oxidized B-chain of insulin suggested that endopeptidase, but also exopeptidase activity was present. After identification, proteases were similar to cysteine protease from Arabidopsis thaliana. In conclusion, proteases exuded by roots may have great potential in the plant nitrogen nutrition.
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Affiliation(s)
- Bartosz Adamczyk
- Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland.
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