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Thomas P, Sekhar AC. Cultivation Versus Molecular Analysis of Banana (Musa sp.) Shoot-Tip Tissue Reveals Enormous Diversity of Normally Uncultivable Endophytic Bacteria. Microb Ecol 2017; 73:885-899. [PMID: 27833995 DOI: 10.1007/s00248-016-0877-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [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: 07/15/2016] [Accepted: 10/10/2016] [Indexed: 05/06/2023]
Abstract
The interior of plants constitutes a unique environment for microorganisms with various organisms inhabiting as endophytes. Unlike subterranean plant parts, aboveground parts are relatively less explored for endophytic microbial diversity. We employed a combination of cultivation and molecular approaches to study the endophytic bacterial diversity in banana shoot-tips. Cultivable bacteria from 20 sucker shoot-tips of cv. Grand Naine included 37 strains under 16 genera and three phyla (Proteobacteria, Actinobacteria, Firmicutes). 16S rRNA gene-ribotyping approach on 799f and 1492r PCR-amplicons to avoid plant organelle sequences was ineffective showing limited bacterial diversity. 16S rRNA metagene profiling targeting the V3-V4 hypervariable region after filtering out the chloroplast (74.2 %), mitochondrial (22.9 %), and unknown sequences (1.1 %) revealed enormous bacterial diversity. Proteobacteria formed the predominant phylum (64 %) succeeded by Firmicutes (12.1 %), Actinobacteria (9.5 %), Bacteroidetes (6.4 %), Planctomycetes, Cyanobacteria, and minor shares (<1 %) of 14 phyla including several candidate phyla besides the domain Euryarchaeota (0.2 %). Microbiome analysis of single shoot-tips through 16S rRNA V3 region profiling showed similar taxonomic richness and diversity and was less affected by plant sequence interferences. DNA extraction kit ominously influenced the phylogenetic diversity. The study has revealed vast diversity of normally uncultivable endophytic bacteria prevailing in banana shoot-tips (20 phyla, 46 classes) with about 2.6 % of the deciphered 269 genera and 1.5 % of the 656 observed species from the same source of shoot-tips attained through cultivation. The predominant genera included several agriculturally important bacteria. The study reveals an immense ecosystem of endophytic bacteria in banana shoot tissues endorsing the earlier documentation of intracellular "Cytobacts" and "Peribacts" with possible roles in plant holobiome and hologenome.
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Affiliation(s)
- Pious Thomas
- Endophytic and Molecular Microbiology Laboratory, Division of Biotechnology, ICAR-Indian Institute of Horticultural Research (IIHR), Hessaraghatta Lake, Bengaluru, 560089, India.
| | - Aparna Chandra Sekhar
- Endophytic and Molecular Microbiology Laboratory, Division of Biotechnology, ICAR-Indian Institute of Horticultural Research (IIHR), Hessaraghatta Lake, Bengaluru, 560089, India
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Marçais B, Piou D, Dezette D, Desprez-Loustau ML. Can Oak Powdery Mildew Severity be Explained by Indirect Effects of Climate on the Composition of the Erysiphe Pathogenic Complex? Phytopathology 2017; 107:570-579. [PMID: 28026998 DOI: 10.1094/phyto-07-16-0268-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 05/20/2023]
Abstract
Coinfection by several pathogens is increasingly recognized as an important feature in the epidemiology and evolution of plant fungal pathogens. Oak mildew is induced by two closely related Erysiphe invasive species (Erysiphe alphitoides and E. quercicola) which differ in their mode of overwintering. We investigated how climate influences the co-occurrence of the two species in oak young stands and whether this is important for the disease epidemiology. We studied the frequency of flag-shoots (i.e., shoots developing from infected buds, usually associated with E. quercicola) in 95 oak regenerations over a 6-year period. Additionally, in 2012 and 2013, the oak mildew severity and the two Erysiphe spp. relative frequencies were determined in both spring and autumn in 51 regenerations and 43 1-year-old plantations of oaks. Both the frequency of flag-shoots and the proportion of Erysiphe lesions with E. quercicola presence were related to climate. We showed that survival of E. quercicola was improved after mild winters, with increase of both the flag-shoot frequency and the proportion of Erysiphe lesions with E. quercicola presence in spring. However, disease severity was not related to any complementarity effect between the two Erysiphe spp. causing oak powdery mildew. By contrast, increased E. alphitoides prevalence in spring was associated with higher oak mildew severity in autumn. Our results point out the critical role of between-season transmission and primary inoculum to explain disease dynamics which could be significant in a climate-warming context.
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Affiliation(s)
- Benoit Marçais
- First author: UMR1136 IAM, INRA, Université de Lorraine, Nancy, F-54280 Champenoux, France; second author: Ministère de l'agriculture, de l'agro-alimentaire et de la forêt DGAL-SDQPV, Département de la Santé des Forêts, 251 rue de Vaugirard, 75732, Paris cedex 15, France; and second, third, and fourth authors: UMR1202 BIOGECO, INRA, University of Bordeaux, F-33610 Cestas, France
| | - Dominique Piou
- First author: UMR1136 IAM, INRA, Université de Lorraine, Nancy, F-54280 Champenoux, France; second author: Ministère de l'agriculture, de l'agro-alimentaire et de la forêt DGAL-SDQPV, Département de la Santé des Forêts, 251 rue de Vaugirard, 75732, Paris cedex 15, France; and second, third, and fourth authors: UMR1202 BIOGECO, INRA, University of Bordeaux, F-33610 Cestas, France
| | - Damien Dezette
- First author: UMR1136 IAM, INRA, Université de Lorraine, Nancy, F-54280 Champenoux, France; second author: Ministère de l'agriculture, de l'agro-alimentaire et de la forêt DGAL-SDQPV, Département de la Santé des Forêts, 251 rue de Vaugirard, 75732, Paris cedex 15, France; and second, third, and fourth authors: UMR1202 BIOGECO, INRA, University of Bordeaux, F-33610 Cestas, France
| | - Marie-Laure Desprez-Loustau
- First author: UMR1136 IAM, INRA, Université de Lorraine, Nancy, F-54280 Champenoux, France; second author: Ministère de l'agriculture, de l'agro-alimentaire et de la forêt DGAL-SDQPV, Département de la Santé des Forêts, 251 rue de Vaugirard, 75732, Paris cedex 15, France; and second, third, and fourth authors: UMR1202 BIOGECO, INRA, University of Bordeaux, F-33610 Cestas, France
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Schneider J, Bundschuh J, Rangel WDM, Guilherme LRG. Potential of different AM fungi (native from As-contaminated and uncontaminated soils) for supporting Leucaena leucocephala growth in As-contaminated soil. Environ Pollut 2017; 224:125-135. [PMID: 28214191 DOI: 10.1016/j.envpol.2017.01.071] [Citation(s) in RCA: 11] [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: 10/03/2016] [Revised: 01/20/2017] [Accepted: 01/27/2017] [Indexed: 06/06/2023]
Abstract
Arbuscular mycorrhizal (AM) fungi inoculation is considered a potential biotechnological tool for an eco-friendly remediation of hazardous contaminants. However, the mechanisms explaining how AM fungi attenuate the phytotoxicity of metal(oid)s, in particular arsenic (As), are still not fully understood. The influence of As on plant growth and the antioxidant system was studied in Leucaena leucocephala plants inoculated with different isolates of AM fungi and exposed to increasing concentrations of As (0, 35, and 75 mg dm-3) in a Typic Quartzipsamment soil. The study was conducted under greenhouse conditions using isolates of AM fungi selected from uncontaminated soils (Acaulospora morrowiae, Rhizophagus clarus, Gigaspora albida; and a mixed inoculum derived from combining these isolates, named AMF Mix) as well as a mix of three isolates from an As-contaminated soil (A. morrowiae, R. clarus, and Paraglomus occultum). After 21 weeks, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were determined in the shoots in addition to measuring plant height and mineral contents. In general, AM fungi have shown multiple beneficial effects on L. leucocephala growth. Although the activity of most of the stress-related enzymes increased in plants associated with AM fungi, the percentage increase caused by adding As to the soil was even greater for non-mycorrhizal plants when compared to AM-fungi inoculated ones, which highlights the phytoprotective effect provided by the AM symbiosis. The highest P/As ratio observed in AM-fungi plants, compared to non-mycorrhizal ones, can be considered a good indicator that the AM fungi alter the pattern of As(V) uptake from As-contaminated soil. Our results underline the role of AM fungi in increasing the tolerance of L. leucocephala to As stress and emphasize the potential of the symbiosis L. leucocephala-R. clarus for As-phytostabilization at moderately As-contaminated soils.
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Affiliation(s)
- Jerusa Schneider
- School of Civil Engineering, Architecture and Urban Design - FEC, Sanitation and Environment Dept., State University of Campinas - UNICAMP, PO Box 6021, 13083-889, Campinas, SP, Brazil; Department of Soil Science, Federal University of Lavras (UFLA), PO Box 3037, 37200-000, Lavras, MG, Brazil.
| | - Jochen Bundschuh
- Deputy Vice-Chancellor's Office (Research and Innovation), University of Southern Queensland, West Street, Toowoomba, 4350, QLD, Australia; Faculty of Health, Engineering and Sciences, University of Southern Queensland, West Street, Toowoomba, 4350, QLD, Australia; KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-10044, Stockholm, Sweden
| | - Wesley de Melo Rangel
- Department of Soil Science, Federal University of Lavras (UFLA), PO Box 3037, 37200-000, Lavras, MG, Brazil
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Khaksar G, Treesubsuntorn C, Thiravetyan P. Impact of endophytic colonization patterns on Zamioculcas zamiifolia stress response and in regulating ROS, tryptophan and IAA levels under airborne formaldehyde and formaldehyde-contaminated soil conditions. Plant Physiol Biochem 2017; 114:1-9. [PMID: 28246037 DOI: 10.1016/j.plaphy.2017.02.016] [Citation(s) in RCA: 14] [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: 12/07/2016] [Revised: 02/04/2017] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
Deeper understanding of plant-endophyte interactions under abiotic stress would provide new insights into phytoprotection and phytoremediation enhancement. Many studies have investigated the positive role of plant-endophyte interactions in providing protection to the plant against pollutant stress through auxin (indole-3-acetic acid (IAA)) production. However, little is known about the impact of endophytic colonization patterns on plant stress response in relation to reactive oxygen species (ROS) and IAA levels. Moreover, the possible effect of pollutant phase on plant stress response is poorly understood. Here, we elucidated the impact of endophytic colonization patterns on plant stress response under airborne formaldehyde compared to formaldehyde-contaminated soil. ROS, tryptophan and IAA levels in the roots and shoots of endophyte-inoculated and non-inoculated plants in the presence and absence of formaldehyde were measured. Strain-specific quantitative polymerase chain reaction (qPCR) was used to investigate dynamics of endophyte colonization. Under the initial exposure to airborne formaldehyde, non-inoculated plants accumulated more tryptophan in the shoots (compared to the roots) to synthesize IAA. However, endophyte-inoculated plants behaved differently as they synthesized and accumulated more tryptophan in the roots and, hence, higher levels of IAA accumulation and exudation within roots which might act as a signaling molecule to selectively recruit B. cereus ERBP. Under continuous airborne formaldehyde stress, higher levels of ROS accumulation in the shoots pushed the plant to synthesize more tryptophan and IAA in the shoots (compared to the roots). Higher levels of IAA in the shoots might act as the potent driving force to relocalize B. cereus ERBP from roots to the shoots. In contrast, under formaldehyde-contaminated soil, B. cereus ERBP colonized root tissues without moving to the shoots since there was a sharp increase in ROS, tryptophan and IAA levels of the roots without any significant increase in the shoots. Pollutant phase affected endophytic colonization patterns and plant stress responses differently.
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Affiliation(s)
- Gholamreza Khaksar
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
| | - Chairat Treesubsuntorn
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
| | - Paitip Thiravetyan
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
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55
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Navarro-Torre S, Barcia-Piedras JM, Mateos-Naranjo E, Redondo-Gómez S, Camacho M, Caviedes MA, Pajuelo E, Rodríguez-Llorente ID. Assessing the role of endophytic bacteria in the halophyte Arthrocnemum macrostachyum salt tolerance. Plant Biol (Stuttg) 2017; 19:249-256. [PMID: 27770586 DOI: 10.1111/plb.12521] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [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: 09/14/2016] [Accepted: 10/18/2016] [Indexed: 05/13/2023]
Abstract
There is an increasing interest to use halophytes for revegetation of salt affected ecosystems, as well as in understanding their mechanisms of salt tolerance. We hypothesized that bacteria from the phyllosphere of these plants might play a key role in its high tolerance to excessive salinity. Eight endophytic bacteria belonging to Bacillus and closely related genera were isolated from phyllosphere of the halophyte Arthrocnemum macrostachyum growing in salty agricultural soils. The presence of plant-growth promoting (PGP) properties, enzymatic activities and tolerance towards NaCl was determined. Effects of inoculation on seeds germination and adult plant growth under experimental NaCl treatments (0, 510 and 1030 mM NaCl) were studied. Inoculation with a consortium including the best performing bacteria improved considerably the kinetics of germination and the final germination percentage of A. macrostachyum seeds. At high NaCl concentrations (1030 mM), inoculation of plants mitigated the effects of high salinity on plant growth and physiological performance and, in addition, this consortium appears to have increased the potential of A. macrostachyum to accumulate Na+ in its shoots, thus improving sodium phytoextraction capacity. Bacteria isolated from A. macrostachyum phyllosphere seem to play an important role in plant salt tolerance under stressing salt concentrations. The combined use of A. macrostachyum and its microbiome can be an adequate tool to enhance plant adaptation and sodium phytoextraction during restoration of salt degraded soils.
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Affiliation(s)
- S Navarro-Torre
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - J M Barcia-Piedras
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- IFAPA, Centro Las Torres -Tomejil, Sevilla, Spain
| | - E Mateos-Naranjo
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - S Redondo-Gómez
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - M Camacho
- IFAPA, Centro Las Torres -Tomejil, Sevilla, Spain
| | - M A Caviedes
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - E Pajuelo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - I D Rodríguez-Llorente
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
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Khaksar G, Treesubsuntorn C, Thiravetyan P. Euphorbia milii-native bacteria interactions under airborne formaldehyde stress: Effect of epiphyte and endophyte inoculation in relation to IAA, ethylene and ROS levels. Plant Physiol Biochem 2017; 111:284-294. [PMID: 27987473 DOI: 10.1016/j.plaphy.2016.12.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [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: 11/16/2016] [Accepted: 12/06/2016] [Indexed: 06/06/2023]
Abstract
Better understanding of plant-bacteria interactions under stress is of the prime importance for enhancing airborne pollutant phytoremediation. No studies have investigated plant-epiphyte interactions compared to plant-endophyte interactions under airborne formaldehyde stress in terms of plant Indole-3-acetic acid (IAA), ethylene, reactive oxygen species (ROS) levels and pollutant removal efficiency. Euphorbia milii was inoculated with native plant growth-promoting (PGP) endophytic and epiphytic isolates individually to investigate plant-endophyte compared to plant-epiphyte interactions under continuous formaldehyde fumigation. Under airborne formaldehyde stress, endophyte interacts with its host plant closely and provides higher levels of IAA which protected the plant against formaldehyde phytotoxicity by lowering intracellular ROS, ethylene levels and maintaining shoot epiphytic community; hence, higher pollutant removal. However, plant-epiphyte interactions could not provide enough IAA to confer protection against formaldehyde stress; thus, increased ROS and ethylene levels, large decrease in shoot epiphytic population and lower pollutant removal although epiphyte contacts with airborne pollutant directly (has greater access to gaseous formaldehyde). Endophyte-inoculated plant synthesized more tryptophan as a signaling molecule for its associated bacteria to produce IAA compared to the epiphyte-inoculated one. Under stress, PGP endophyte interacts with its host closely; thus, better protection against stress and higher pollutant removal compared to epiphyte which has limited interactions with the host plant; hence, lower pollutant removal.
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Affiliation(s)
- Gholamreza Khaksar
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
| | - Chairat Treesubsuntorn
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
| | - Paitip Thiravetyan
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
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Gommers CMM, Keuskamp DH, Buti S, van Veen H, Koevoets IT, Reinen E, Voesenek LACJ, Pierik R. Molecular Profiles of Contrasting Shade Response Strategies in Wild Plants: Differential Control of Immunity and Shoot Elongation. Plant Cell 2017; 29:331-344. [PMID: 28138015 PMCID: PMC5354195 DOI: 10.1105/tpc.16.00790] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/10/2017] [Accepted: 01/25/2017] [Indexed: 05/06/2023]
Abstract
Plants growing at high densities elongate their shoots to reach for light, a response known as the shade avoidance syndrome (SAS). Phytochrome-mediated detection of far-red light reflection from neighboring plants activates growth-promoting molecular pathways leading to SAS However, it is unknown how plants that complete their life cycle in the forest understory and are shade tolerant prevent SAS when exposed to shade. Here, we show how two wild Geranium species from different native light environments regulate contrasting responses to light quality cues. A comparative RNA sequencing approach unveiled the molecular underpinnings of their contrasting growth responses to far-red light enrichment. It also identified differential phytochrome control of plant immunity genes and confirmed that far-red enrichment indeed contrastingly affects resistance against Botrytis cinerea between the two species. Furthermore, we identify a number of candidate regulators of differential shade avoidance. Three of these, the receptor-like kinases FERONIA and THESEUS1 and the non-DNA binding bHLH protein KIDARI, are functionally validated in Arabidopsis thaliana through gene knockout and/or overexpression studies. We propose that these components may be associated with either showing or not showing shade avoidance responses.
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Affiliation(s)
- Charlotte M M Gommers
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Diederik H Keuskamp
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Sara Buti
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Hans van Veen
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Iko T Koevoets
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Emilie Reinen
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Laurentius A C J Voesenek
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Ronald Pierik
- Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
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Matei PM, Sánchez-Báscones M, Bravo-Sánchez CT, Martín-Ramos P, Martín-Villullas MT, García-González MC, Hernández-Navarro S, Navas-Gracia LM, Martín-Gil J. Hygienization and control of Diplodia seriata fungus in vine pruning waste composting and its seasonal variability in open and closed systems. Waste Manag 2016; 58:126-134. [PMID: 27522281 DOI: 10.1016/j.wasman.2016.08.002] [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] [Received: 07/18/2015] [Revised: 08/01/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
After the ban on sodium arsenite, waste management alternatives to the prevalent burning method, such as the hygienization and biodegradation in solid phase by composting, are required for the pruned material from grapevines affected by various fungi. In this work the dynamics of a fungus associated with vine decay (Diplodia seriata) during the composting process of a mixture of laying hen manure and vine pruning waste (2:1w/w) have been investigated in an open pile and a discontinuous closed biodigester. Through the optimization of the various physical-chemical parameters, hygienization of the infected waste materials was attained, yielding class-A organo-mineral fertilizers. Nevertheless, important differences in the efficiency of each system were observed: whereas in the open pile it took 10days to control D. seriata and 35 additional composting days to achieve full inactivation, in the discontinuous biodigester the fungus was entirely inactivated within the first 3-7days. Finally, the impact of seasonal variability was assessed and summer temperatures shown to have greater significance in the open pile.
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Affiliation(s)
- Petruta M Matei
- Agriculture and Forestry Science Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 57, 34004 Palencia, Spain
| | - Mercedes Sánchez-Báscones
- Agriculture and Forestry Science Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 57, 34004 Palencia, Spain
| | - Carmen T Bravo-Sánchez
- Agriculture and Forestry Science Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 57, 34004 Palencia, Spain
| | - Pablo Martín-Ramos
- Department of Agricultural and Environmental Sciences, Higher Polytechnic School of Huesca, University of Zaragoza, Carretera de Cuarte, s/n, 22071 Huesca, Spain.
| | - M Teresa Martín-Villullas
- Agriculture and Forestry Science Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 57, 34004 Palencia, Spain; ITACYL, Finca Zamadueñas, Ctra. de Burgos, km. 119, 47071 Valladolid, Spain
| | | | - Salvador Hernández-Navarro
- Agriculture and Forestry Engineering Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia, Spain
| | - Luis M Navas-Gracia
- Agriculture and Forestry Engineering Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia, Spain
| | - Jesús Martín-Gil
- Agriculture and Forestry Engineering Department, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia, Spain
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Hu J, Wang N. Evaluation of the Spatiotemporal Dynamics of Oxytetracycline and Its Control Effect Against Citrus Huanglongbing via Trunk Injection. Phytopathology 2016; 106:1495-1503. [PMID: 27482624 DOI: 10.1094/phyto-02-16-0114-r] [Citation(s) in RCA: 24] [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] [Indexed: 05/22/2023]
Abstract
Citrus huanglongbing (HLB) or greening is a devastating bacterial disease that has destroyed millions of trees and is associated with phloem-residing 'Candidatus Liberibacter asiaticus' (Las) in Florida. In this study, we evaluated the spatiotemporal dynamics of oxytetracycline in planta and its control effect against HLB via trunk injection. Las-infected 'Hamlin' sweet orange trees on 'Swingle' citrumelo rootstock at the early stage of decline were treated with oxytetracycline hydrochloride (OTC) using trunk injection with varying number of injection ports. Spatiotemporal distribution of OTC and dynamics of Las populations were monitored by high-performance liquid chromatography method and qPCR assay, respectively. Uniform distribution of OTC throughout tree canopies and root system was achieved 2 days postinjection. High levels of OTC (>850 µg/kg) were maintained in leaf and root for at least 1 month and moderate OTC (>500 µg/kg) persisted for more than 9 months. Reduction of Las populations in root system and leaves of OTC-treated trees were over 95% and 99% (i.e., 1.76 and 2.19 log reduction) between 2 and 28 days postinjection. Conditions of trees receiving OTC treatment were improved, fruit yield was increased, and juice acidity was lowered than water-injected control even though their differences were not statistically significant during the test period. Our study demonstrated that trunk injection of OTC could be used as an effective measure for integrated management of citrus HLB.
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Affiliation(s)
- Jiahuai Hu
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred
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Lovelock DA, Šola I, Marschollek S, Donald CE, Rusak G, van Pée KH, Ludwig-Müller J, Cahill DM. Analysis of salicylic acid-dependent pathways in Arabidopsis thaliana following infection with Plasmodiophora brassicae and the influence of salicylic acid on disease. Mol Plant Pathol 2016; 17:1237-51. [PMID: 26719902 PMCID: PMC6638340 DOI: 10.1111/mpp.12361] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [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: 07/23/2015] [Revised: 12/23/2015] [Accepted: 12/26/2015] [Indexed: 05/19/2023]
Abstract
Salicylic acid (SA) biosynthesis, the expression of SA-related genes and the effect of SA on the Arabidopsis-Plasmodiophora brassicae interaction were examined. Biochemical analyses revealed that, in P. brassicae-infected Arabidopsis, the majority of SA is synthesized from chorismate. Real-time monitored expression of a gene for isochorismate synthase was induced on infection. SA can be modified after accumulation, either by methylation, improving its mobility, or by glycosylation, as one possible reaction for inactivation. Quantitative reverse transcription-polymerase chain reaction (qPCR) confirmed the induction of an SA methyltransferase gene, whereas SA glucosyltransferase expression was not changed after infection. Col-0 wild-type (wt) did not provide a visible phenotypic resistance response, whereas the Arabidopsis mutant dnd1, which constitutively activates the immune system, showed reduced gall scores. As dnd1 showed control of the pathogen, exogenous SA was applied to Arabidopsis in order to test whether it could suppress clubroot. In wt, sid2 (SA biosynthesis), NahG (SA-deficient) and npr1 (SA signalling-impaired) mutants, SA treatment did not alter the gall score, but positively affected the shoot weight. This suggests that SA alone is not sufficient for Arabidopsis resistance against P. brassicae. Semi-quantitative PCR revealed that wt, cpr1, dnd1 and sid2 showed elevated PR-1 expression on P. brassicae and SA + P. brassicae inoculation at 2 and 3 weeks post-inoculation (wpi), whereas NahG and npr1 showed no expression. This work contributes to the understanding of SA involvement in the Arabidopsis-P. brassicae interaction.
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Affiliation(s)
- David A Lovelock
- Deakin University, Faculty of Science, Engineering and Built Environment, School of Life and Environmental Science, Geelong Campus at Waurn Ponds, Vic. 3217, Australia.
| | - Ivana Šola
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
| | - Sabine Marschollek
- Institute of Botany, Technische Universität Dresden, D-01062, Dresden, Germany
| | - Caroline E Donald
- Department of Primary Industries, Private bag 15, Ferntree Gully DC, Vic., 3156, Australia
| | - Gordana Rusak
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia
| | - Karl-Heinz van Pée
- Department of Chemistry, Biochemistry, Technische Universität Dresden, D-01062, Dresden, Germany
| | - Jutta Ludwig-Müller
- Institute of Botany, Technische Universität Dresden, D-01062, Dresden, Germany
| | - David M Cahill
- Deakin University, Faculty of Science, Engineering and Built Environment, School of Life and Environmental Science, Geelong Campus at Waurn Ponds, Vic. 3217, Australia
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Akiyama H, Hoshino YT, Itakura M, Shimomura Y, Wang Y, Yamamoto A, Tago K, Nakajima Y, Minamisawa K, Hayatsu M. Mitigation of soil N2O emission by inoculation with a mixed culture of indigenous Bradyrhizobium diazoefficiens. Sci Rep 2016; 6:32869. [PMID: 27633524 PMCID: PMC5025649 DOI: 10.1038/srep32869] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [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: 05/27/2016] [Accepted: 08/11/2016] [Indexed: 11/11/2022] Open
Abstract
Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean is an important leguminous crop worldwide. Soybean hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition of the root nodules. Our previous study showed that N2O reductase can be used to mitigate N2O emission from soybean fields during nodule decomposition by inoculation with nosZ++ strains [mutants with increased N2O reductase (N2OR) activity] of Bradyrhizobium diazoefficiens. Here, we show that N2O emission can be reduced at the field scale by inoculation with a mixed culture of indigenous nosZ+ strains of B. diazoefficiens USDA110 group isolated from Japanese agricultural fields. Our results also suggested that nodule nitrogen is the main source of N2O production during nodule decomposition. Isolating nosZ+ strains from local soybean fields would be more applicable and feasible for many soybean-producing countries than generating mutants.
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Affiliation(s)
- Hiroko Akiyama
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Yuko Takada Hoshino
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Manabu Itakura
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Yumi Shimomura
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Yong Wang
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Akinori Yamamoto
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Kanako Tago
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Yasuhiro Nakajima
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
- Advanced Analysis Center, NARO, 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
| | - Kiwamu Minamisawa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Masahito Hayatsu
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan
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Ravnskov S, Larsen J. Functional compatibility in cucumber mycorrhizas in terms of plant growth performance and foliar nutrient composition. Plant Biol (Stuttg) 2016; 18:816-823. [PMID: 27094118 DOI: 10.1111/plb.12465] [Citation(s) in RCA: 6] [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: 02/26/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
Functional compatibility in cucumber mycorrhizas in terms of plant and fungal growth, and foliar nutrient composition from all possible combinations of six cucumber varieties and three species of arbuscular mycorrhizal (AM) fungi was evaluated. Measurements of foliar nutrient composition included N, P, K, Mg, Ca, Na, Fe, Zn, Mn and Cu. Growth of AM fungi was measured in terms of root colonisation, as examined with microscopy and the AM fungus biomarker fatty acid 16:1ω5 from both phospholipids and neutral lipids. Different responses of plant growth and foliar nutrient profiles were observed for the different AM symbioses examined. The AM fungus Claroideoglomus claroideum caused growth depression in association with four out of six cucumber varieties; Rhizophagus irregularis caused growth promotion in one of six cucumber varieties; whereas Funneliformis mosseae had no effect on the growth performance of any of the cucumber varieties examined. All three AM fungi markedly altered host plant shoot nutrient composition, with the strongest contrast observed between cucumber-R. irregularis symbioses and non-mycorrhizal cucumber plants, independent of cucumber variety. On the other hand, AM fungal growth in roots differed between the three AM fungi, but was unaffected by host genotype. Strong build-up of storage lipids was observed for R. irregularis, which was more moderate in the two other AM fungi. In conclusion, strong differential responses of cucumber varieties to inoculation with different AM fungi in terms of growth and shoot nutrient composition revealed high functional diversity in AM symbioses in cucumber plants.
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Affiliation(s)
- S Ravnskov
- Department of Agroecology, Aarhus University, Flakkebjerg, Slagelse, Denmark
| | - J Larsen
- Laboratorio de Agroecología, Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, México
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de Souza RSC, Okura VK, Armanhi JSL, Jorrín B, Lozano N, da Silva MJ, González-Guerrero M, de Araújo LM, Verza NC, Bagheri HC, Imperial J, Arruda P. Unlocking the bacterial and fungal communities assemblages of sugarcane microbiome. Sci Rep 2016; 6:28774. [PMID: 27358031 PMCID: PMC4928081 DOI: 10.1038/srep28774] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [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: 02/15/2016] [Accepted: 06/10/2016] [Indexed: 12/13/2022] Open
Abstract
Plant microbiome and its manipulation herald a new era for plant biotechnology with the potential to benefit sustainable crop production. However, studies evaluating the diversity, structure and impact of the microbiota in economic important crops are still rare. Here we describe a comprehensive inventory of the structure and assemblage of the bacterial and fungal communities associated with sugarcane. Our analysis identified 23,811 bacterial OTUs and an unexpected 11,727 fungal OTUs inhabiting the endophytic and exophytic compartments of roots, shoots, and leaves. These communities originate primarily from native soil around plants and colonize plant organs in distinct patterns. The sample type is the primary driver of fungal community assemblage, and the organ compartment plays a major role in bacterial community assemblage. We identified core bacterial and fungal communities composed of less than 20% of the total microbial richness but accounting for over 90% of the total microbial relative abundance. The roots showed 89 core bacterial families, 19 of which accounted for 44% of the total relative abundance. Stalks are dominated by groups of yeasts that represent over 12% of total relative abundance. The core microbiome described here comprise groups whose biological role underlies important traits in plant growth and fermentative processes.
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Affiliation(s)
- Rafael Soares Correa de Souza
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | - Vagner Katsumi Okura
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | - Jaderson Silveira Leite Armanhi
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | - Beatriz Jorrín
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA Campus Montegancedo UPM, 28223 -Pozuelo de Alarcón (Madrid), Spain
| | - Núria Lozano
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA Campus Montegancedo UPM, 28223 -Pozuelo de Alarcón (Madrid), Spain
| | - Márcio José da Silva
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA Campus Montegancedo UPM, 28223 -Pozuelo de Alarcón (Madrid), Spain
| | - Laura Migliorini de Araújo
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | - Natália Cristina Verza
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
| | | | - Juan Imperial
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA Campus Montegancedo UPM, 28223 -Pozuelo de Alarcón (Madrid), Spain
- Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Paulo Arruda
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), 13083-875, Campinas, SP, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970, Campinas, SP, Brazil
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Hautea DM, Taylo LD, Masanga APL, Sison MLJ, Narciso JO, Quilloy RB, Hautea RA, Shotkoski FA, Shelton AM. Field Performance of Bt Eggplants (Solanum melongena L.) in the Philippines: Cry1Ac Expression and Control of the Eggplant Fruit and Shoot Borer (Leucinodes orbonalis Guenée). PLoS One 2016; 11:e0157498. [PMID: 27322533 PMCID: PMC4913932 DOI: 10.1371/journal.pone.0157498] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 03/17/2016] [Accepted: 05/31/2016] [Indexed: 11/18/2022] Open
Abstract
Plants expressing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling insect pests in maize and cotton globally. However, there are few Bt vegetable crops. Eggplant (Solanum melongena) is a popular vegetable grown throughout Asia that is heavily treated with insecticides to control the eggplant fruit and shoot borer, Leucinodes orbonalis (EFSB). Herein we provide the first publicly available data on field performance in Asia of eggplant engineered to produce the Cry1Ac protein. Replicated field trials with five Bt eggplant open-pollinated (OP) lines from transformation event EE-1 and their non-Bt comparators were conducted over three cropping seasons in the Philippines from 2010–2012. Field trials documented levels of Cry1Ac protein expressed in plants and evaluated their efficacy against the primary target pest, EFSB. Cry1Ac concentrations ranged from 0.75–24.7 ppm dry weight with the highest in the terminal leaves (or shoots) and the lowest in the roots. Cry1Ac levels significantly increased from the vegetative to the reproductive stage. Bt eggplant lines demonstrated excellent control of EFSB. Pairwise analysis of means detected highly significant differences between Bt eggplant lines and their non-Bt comparators for all field efficacy parameters tested. Bt eggplant lines demonstrated high levels of control of EFSB shoot damage (98.6–100%) and fruit damage (98.1–99.7%) and reduced EFSB larval infestation (95.8–99.3%) under the most severe pest pressure during trial 2. Moths that emerged from larvae collected from Bt plants in the field and reared in their Bt eggplant hosts did not produce viable eggs or offspring. These results demonstrate that Bt eggplant lines containing Cry1Ac event EE-1 provide outstanding control of EFSB and can dramatically reduce the need for conventional insecticides.
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Affiliation(s)
- Desiree M. Hautea
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
- * E-mail: ;
| | - Lourdes D. Taylo
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Anna Pauleen L. Masanga
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Maria Luz J. Sison
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Josefina O. Narciso
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Reynaldo B. Quilloy
- Institute of Plant Breeding/CSC, College of Agriculture, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Randy A. Hautea
- International Service for the Acquisition of Agri-Biotech Applications, Los Baños, Laguna, 4030, Philippines
| | - Frank A. Shotkoski
- International Programs, Cornell University, Ithaca, New York, 14853, United States of America
| | - Anthony M. Shelton
- Department of Entomology, Cornell/NYSAES, Geneva, New York, 14456, United States of America
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Djedidi S, Kojima K, Ohkama-Ohtsu N, Bellingrath-Kimura SD, Yokoyama T. Growth and (137)Cs uptake and accumulation among 56 Japanese cultivars of Brassica rapa, Brassica juncea and Brassica napus grown in a contaminated field in Fukushima: Effect of inoculation with a Bacillus pumilus strain. J Environ Radioact 2016; 157:27-37. [PMID: 26986237 DOI: 10.1016/j.jenvrad.2016.02.024] [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: 11/12/2015] [Revised: 02/18/2016] [Accepted: 02/23/2016] [Indexed: 06/05/2023]
Abstract
Fifty six local Japanese cultivars of Brassica rapa (40 cultivars), Brassica juncea (10 cultivars) and Brassica napus (6 cultivars) were assessed for variability in growth and (137)Cs uptake and accumulation in association with a Bacillus pumilus strain. Field trial was conducted at a contaminated farmland in Nihonmatsu city, in Fukushima prefecture. Inoculation resulted in different responses of the cultivars in terms of growth and radiocesium uptake and accumulation. B. pumilus induced a significant increase in shoot dry weight in 12 cultivars that reached up to 40% in one B. rapa and three B. juncea cultivars. Differences in radiocesium uptake were observed between the cultivars of each Brassica species. Generally, inoculation resulted in a significant increase in (137)Cs uptake in 22 cultivars, while in seven cultivars it was significantly decreased. Regardless of plant cultivar and bacterial inoculation, the transfer of (137)Cs to the plant shoots (TF) varied by a factor of up to 5 and it ranged from to 0.011 to 0.054. Five inoculated cultivars, showed enhanced shoot dry weights and decreased (137)Cs accumulations, among which two B. rapa cultivars named Bitamina and Nozawana had a significantly decreased (137)Cs accumulation in their shoots. Such cultivars could be utilized to minimize the entry of radiocesium into the food chain; however, verifying the consistency of their radiocesium accumulation in other soils is strongly required. Moreover, the variations in growth and radiocesium accumulation, as influenced by Bacillus inoculation, could help selecting well grown inoculated Brassica cultivars with low radiocesium accumulation in their shoots.
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Affiliation(s)
- Salem Djedidi
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Katsuhiro Kojima
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Naoko Ohkama-Ohtsu
- Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | | | - Tadashi Yokoyama
- Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
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Saraswathi MS, Kannan G, Uma S, Thangavelu R, Backiyarani S. Improvement of banana cv. Rasthali (Silk, AAB) against Fusarium oxysporum f.sp. cubense (VCG 0124/5) through induced mutagenesis: Determination of LD50 specific to mutagen, explants, toxins and in vitro and in vivo screening for Fusarium wilt resistance. Indian J Exp Biol 2016; 54:345-353. [PMID: 27319054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Shoot tips and in vitro grown proliferating buds of banana cv. Rasthali (Silk, AAB) were treated with various concentrations and durations of chemical mutagens viz., EMS, NaN3 and DES. LD50 for shoot tips based on 50% reduction in fresh weight was determined as 2% for 3 h, 0.02% for 5 h and 0.15% for 5 h, while for proliferating buds, they were 0.6% for 30 min, 0.01% for 2 h and 0.06% for 2 h for the mutagens EMS, NaN3 and DES, respectively. Subsequently, the mutated explants were screened in vitro against fusarium wilt using selection agents like fusaric acid and culture filtrate. LD50 for in vitro selection agents calculated based on 50% survival of explants was 0.050 mM and 7% for fusaric acid and culture filtrate, respectively and beyond which a rapid decline in growth was observed. This was followed by pot screening which led to the identification of three putative resistant mutants with an internal disease score of 1 (corm completely clean, no vascular discolouration). The putative mutants identified in the present study have also been mass multiplied in vitro.
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Lahrouni M, Oufdou K, El Khalloufi F, Benidire L, Albert S, Göttfert M, Caviedes MA, Rodriguez-Llorente ID, Oudra B, Pajuelo E. Microcystin-tolerant Rhizobium protects plants and improves nitrogen assimilation in Vicia faba irrigated with microcystin-containing waters. Environ Sci Pollut Res Int 2016; 23:10037-10049. [PMID: 26865488 DOI: 10.1007/s11356-016-6223-2] [Citation(s) in RCA: 6] [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: 04/29/2015] [Accepted: 02/01/2016] [Indexed: 06/05/2023]
Abstract
Irrigation of crops with microcystins (MCs)-containing waters-due to cyanobacterial blooms-affects plant productivity and could be a way for these potent toxins entering the food chain. This study was performed to establish whether MC-tolerant rhizobia could benefit growth, nodulation, and nitrogen metabolism of faba bean plants irrigated with MC-containing waters. For that, three different rhizobial strains-with different sensitivity toward MCs-were used: RhOF96 (most MC-sensitive strain), RhOF125 (most MC-tolerant strain), or Vicz1.1 (reference strain). As a control, plants grown without rhizobia and fertilized by NH4NO3 were included in the study. MC exposure decreased roots (30-37 %) and shoots (up to 15 %) dry weights in un-inoculated plants, whereas inoculation with rhizobia protects plants toward the toxic effects of MCs. Nodulation and nitrogen content were significantly impaired by MCs, with the exception of plants inoculated with the most tolerant strain RhOF125. In order to deep into the effect of inoculation on nitrogen metabolism, the nitrogen assimilatory enzymes (glutamine synthetase (GS) and glutamate synthase (GOGAT)) were investigated: Fertilized plants showed decreased levels (15-30 %) of these enzymes, both in shoots and roots. By contrast, inoculated plants retained the levels of these enzymes in shoots and roots, as well as the levels of NADH-GOGAT activity in nodules. We conclude that the microcystin-tolerant Rhizobium protects faba bean plants and improves nitrogen assimilation when grown in the presence of MCs.
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Affiliation(s)
- Majida Lahrouni
- Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco
- Technische Universität Dresden, Institut für Genetik, Helmholtzstr. 10, D-01069, Dresden, Germany
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, c/ Profesor García González, 2, 41012, Sevilla, Spain
| | - Khalid Oufdou
- Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco
| | - Fatima El Khalloufi
- Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco
- University Hassan 1st. Polydisciplinary Faculty of Khouribga, BP. 145, 25000, Khouribga, Morocco
| | - Loubna Benidire
- Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco
| | - Susann Albert
- Technische Universität Dresden, Institut für Genetik, Helmholtzstr. 10, D-01069, Dresden, Germany
| | - Michael Göttfert
- Technische Universität Dresden, Institut für Genetik, Helmholtzstr. 10, D-01069, Dresden, Germany
| | - Miguel A Caviedes
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, c/ Profesor García González, 2, 41012, Sevilla, Spain
| | - Ignacio D Rodriguez-Llorente
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, c/ Profesor García González, 2, 41012, Sevilla, Spain
| | - Brahim Oudra
- Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, PO Box 2390, Marrakech, Morocco
| | - Eloísa Pajuelo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, c/ Profesor García González, 2, 41012, Sevilla, Spain.
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Schüßler A, Krüger C, Urgiles N. Phylogenetically diverse AM fungi from Ecuador strongly improve seedling growth of native potential crop trees. Mycorrhiza 2016; 26:199-207. [PMID: 26260945 DOI: 10.1007/s00572-015-0659-y] [Citation(s) in RCA: 11] [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: 09/14/2014] [Accepted: 07/27/2015] [Indexed: 06/04/2023]
Abstract
In many deforested regions of the tropics, afforestation with native tree species could valorize a growing reservoir of degraded, previously overused and abandoned land. The inoculation of tropical tree seedlings with arbuscular mycorrhizal fungi (AM fungi) can improve tree growth and viability, but efficiency may depend on plant and AM fungal genotype. To study such effects, seven phylogenetically diverse AM fungi, native to Ecuador, from seven genera and a non-native AM fungus (Rhizophagus irregularis DAOM197198) were used to inoculate the tropical potential crop tree (PCT) species Handroanthus chrysanthus (synonym Tabebuia chrysantha), Cedrela montana, and Heliocarpus americanus. Twenty-four plant-fungus combinations were studied in five different fertilization and AMF inoculation treatments. Numerous plant growth parameters and mycorrhizal root colonization were assessed. The inoculation with any of the tested AM fungi improved seedling growth significantly and in most cases reduced plant mortality. Plants produced up to threefold higher biomass, when compared to the standard nursery practice. AM fungal inoculation alone or in combination with low fertilization both outperformed full fertilization in terms of plant growth promotion. Interestingly, root colonization levels for individual fungi strongly depended on the host tree species, but surprisingly the colonization strength did not correlate with plant growth promotion. The combination of AM fungal inoculation with a low dosage of slow release fertilizer improved PCT seedling performance strongest, but also AM fungal treatments without any fertilization were highly efficient. The AM fungi tested are promising candidates to improve management practices in tropical tree seedling production.
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Affiliation(s)
- Arthur Schüßler
- Genetics Institute, Department of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 4, 82152, Planegg-Martinsried, Germany.
| | - Claudia Krüger
- Genetics Institute, Department of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 4, 82152, Planegg-Martinsried, Germany
| | - Narcisa Urgiles
- Genetics Institute, Department of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 4, 82152, Planegg-Martinsried, Germany
- Forestry School, Universidad Nacional de Loja (UNL), Ciudad Universitaria Guillermo Falconí Espinosa, La Argelia, Loja, Ecuador
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Wu QS, Liu CY, Zhang DJ, Zou YN, He XH, Wu QH. Mycorrhiza alters the profile of root hairs in trifoliate orange. Mycorrhiza 2016; 26:237-247. [PMID: 26499883 DOI: 10.1007/s00572-015-0666-z] [Citation(s) in RCA: 11] [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: 08/20/2015] [Accepted: 10/15/2015] [Indexed: 06/05/2023]
Abstract
Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production.
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Affiliation(s)
- Qiang-Sheng Wu
- College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China.
- Institute of Root Biology, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China.
| | - Chun-Yan Liu
- College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
- Institute of Root Biology, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
| | - De-Jian Zhang
- College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
- Institute of Root Biology, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
| | - Ying-Ning Zou
- College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
- Institute of Root Biology, Yangtze University, Jingzhou, 434025, Hubei, People's Republic of China
| | - Xin-Hua He
- School of Plant Biology, University of Western Australia, Crawley, WA, 6009, Australia
- Department of Environmental Sciences, University of Sydney, Eveleigh, NSW, 2015, Australia
| | - Qing-Hua Wu
- Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Kralove, Hradec Kralove, Czech Republic
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70
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Rosier A, Bishnoi U, Lakshmanan V, Sherrier DJ, Bais HP. A perspective on inter-kingdom signaling in plant-beneficial microbe interactions. Plant Mol Biol 2016; 90:537-48. [PMID: 26792782 DOI: 10.1007/s11103-016-0433-3] [Citation(s) in RCA: 44] [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: 03/17/2015] [Accepted: 01/06/2016] [Indexed: 05/14/2023]
Abstract
Recent work has shown that the rhizospheric and phyllospheric microbiomes of plants are composed of highly diverse microbial species. Though the information pertaining to the diversity of the aboveground and belowground microbes associated with plants is known, an understanding of the mechanisms by which these diverse microbes function is still in its infancy. Plants are sessile organisms, that depend upon chemical signals to interact with the microbiota. Of late, the studies related to the impact of microbes on plants have gained much traction in the research literature, supporting diverse functional roles of microbes on plant health. However, how these microbes interact as a community to confer beneficial traits to plants is still poorly understood. Recent advances in the use of "biologicals" as bio-fertilizers and biocontrol agents for sustainable agricultural practices is promising, and a fundamental understanding of how microbes in community work on plants could help this approach be more successful. This review attempts to highlight the importance of different signaling events that mediate a beneficial plant microbe interaction. Fundamental research is needed to understand how plants react to different benign microbes and how these microbes are interacting with each other. This review highlights the importance of chemical signaling, and biochemical and genetic events which determine the efficacy of benign microbes to promote the development of beneficial traits in plants.
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Affiliation(s)
- Amanda Rosier
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
- Delaware Biotechnology Institute, Newark, DE, 19711, USA
| | - Usha Bishnoi
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
- Delaware Biotechnology Institute, Newark, DE, 19711, USA
| | - Venkatachalam Lakshmanan
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
- Delaware Biotechnology Institute, Newark, DE, 19711, USA
| | - D Janine Sherrier
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
- Delaware Biotechnology Institute, Newark, DE, 19711, USA
| | - Harsh P Bais
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA.
- Delaware Biotechnology Institute, Newark, DE, 19711, USA.
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Foley RC, Kidd BN, Hane JK, Anderson JP, Singh KB. Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat. PLoS One 2016; 11:e0152548. [PMID: 27031952 PMCID: PMC4816451 DOI: 10.1371/journal.pone.0152548] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [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: 11/05/2015] [Accepted: 03/16/2016] [Indexed: 01/18/2023] Open
Abstract
Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.
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Affiliation(s)
- Rhonda C. Foley
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - Brendan N. Kidd
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - James K. Hane
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - Jonathan P. Anderson
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
- The UWA Institute of Agriculture, University of Western Australia, Crawley, WA, Australia
| | - Karam B. Singh
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
- The UWA Institute of Agriculture, University of Western Australia, Crawley, WA, Australia
- * E-mail:
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72
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Armada E, Probanza A, Roldán A, Azcón R. Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants. J Plant Physiol 2016; 192:1-12. [PMID: 26796423 DOI: 10.1016/j.jplph.2015.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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: 08/06/2015] [Revised: 11/19/2015] [Accepted: 11/20/2015] [Indexed: 05/04/2023]
Abstract
This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems.
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Affiliation(s)
- E Armada
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
| | - A Probanza
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad San Pablo CEU, 28668 Boadilla del Monte, Madrid, Spain.
| | - A Roldán
- CSIC-Centro de Edafología y Biología Aplicada del Segura, Department of Soil and Water Conservation, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain.
| | - R Azcón
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
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Gosling P, Jones J, Bending GD. Evidence for functional redundancy in arbuscular mycorrhizal fungi and implications for agroecosystem management. Mycorrhiza 2016; 26:77-83. [PMID: 26100128 DOI: 10.1007/s00572-015-0651-6] [Citation(s) in RCA: 19] [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: 03/18/2015] [Accepted: 06/03/2015] [Indexed: 05/27/2023]
Abstract
Arbuscular mycorrhizal (AM) fungi provide benefits to host plants and show functional diversity, with evidence of functional trait conservation at the family level. Diverse communities of AM fungi ought therefore to provide increased benefits to the host, with implications for the management of sustainable agroecosystems. However, this is often not evident in the literature, with diversity saturation at low species number. Growth and nutrient uptake were measured in onions in the glasshouse on AM-free phosphorus (P)-poor soil, inoculated with between one and seven species of AM fungi in all possible combinations. Inoculation with AM fungi increased shoot dry weight as well as P and copper concentrations in shoots but reduced the concentration of potassium and sulphur. There was little evidence of increased benefit from high AM fungal diversity, and increasing diversity beyond three species did not result in significantly higher shoot weight or P or Cu concentrations. Species of Glomeraceae had the greatest impact on growth and nutrient uptake, while species of Acaulospora and Racocetra did not have a significant impact. Failure to show a benefit from high AM fungal diversity in this and other studies may be the result of experimental conditions, with the benefits of AM fungal diversity only becoming apparent when the host plant is faced with multiple stress factors. Replicating the complex interactions between AM fungi, the host plant and their environment in the laboratory in order to fully understand these interactions is a major challenge to AM research.
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Affiliation(s)
- Paul Gosling
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
- AHDB, Stoneleigh Park, Kenilworth, Warwickshire, CV8 2TL, UK.
| | - Julie Jones
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Gary D Bending
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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74
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Harapas D, Premier R, Tomkins B, Hepworth G, Ajlouni S. Shoot Injury Increases the Level of Persistence of Salmonella enterica Serovar Sofia and Listeria innocua on Cos Lettuce and of Salmonella enterica Serovar Sofia on Chive. J Food Prot 2015; 78:2150-5. [PMID: 26613909 DOI: 10.4315/0362-028x.jfp-15-141] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica serovar Sofia persisted on cos lettuce in the greenhouse. Initial mean counts of the Salmonella on the injured and uninjured cos lettuce were on the order of 6 log CFU/g. After 3 days, the mean count decreased to 4.8 log CFU/g on the injured plants compared with the significantly (P < 0.05) smaller count of 3.4 log CFU/g on the uninjured plants. By the end of the 3-week experiment, the count from the injured plants was 2.9 log CFU/g compared with a count of below the level of detection from the uninjured plants. A similar pattern of bacterial persistence was observed on injured versus uninjured plants by using Listeria innocua on cos lettuce and S. enterica serovar Sofia on chive. The findings reaffirm earlier results with Escherichia coli and increase the impetus to avoid shoot injury during the production of cos lettuce and chive, if bacteria of food safety concern are present.
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Affiliation(s)
- Dean Harapas
- Department of Economic Development, Jobs, Transport and Resources, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University, Bundoora, Victoria 3083, Australia.
| | - Robert Premier
- Global F.S. Pty. Ltd., Forest Hill, Victoria 3131, Australia
| | - Bruce Tomkins
- Department of Economic Development, Jobs, Transport and Resources, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University, Bundoora, Victoria 3083, Australia
| | - Graham Hepworth
- Statistical Consulting Centre, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Said Ajlouni
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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75
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Bélanger PA, Bellenger JP, Roy S. Heavy metal stress in alders: Tolerance and vulnerability of the actinorhizal symbiosis. Chemosphere 2015; 138:300-308. [PMID: 26091871 DOI: 10.1016/j.chemosphere.2015.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 02/13/2015] [Revised: 04/30/2015] [Accepted: 06/02/2015] [Indexed: 06/04/2023]
Abstract
Alders have already demonstrated their potential for the revegetation of both mining and industrial sites. These actinorhizal trees and shrubs and the actinobacteria Frankia associate in a nitrogen-fixing symbiosis which could however be negatively affected by the presence of heavy metals, and accumulate them. In our hydroponic assay with black alders, quantification of the roots and shoots metal concentrations showed that, in the absence of stress, symbiosis increases Mo and Ni root content and simultaneously decreases Mo shoot content. Interestingly, the Mo shoot content also decreases in the presence of Ni, Cu, Pb, Zn and Cd for symbiotic alders. In symbiotic alders, Pb shoot translocation was promoted in presence of Pb. On the other hand, Cd exclusion in symbiotic root tissues was observed with Pb and Cd. In the presence of symbiosis, only Cd and Pb showed translocation into aerial tissues when present in the nutrient solution. Moreover, the translocation of Ni to shoot was prevented by symbiosis in the presence of Cd, Ni and Pb. The hydroponic experiment demonstrated that alders benefit from the symbiosis, producing more biomass (total, root and shoot) than non nodulated alders in control condition, and in the presence of metals (Cu, Ni, Zn, Pb and Cd). Heavy metals did not reduce the nodule numbers (SNN), but the presence of Zn or Cd did reduce nodule allocation. Our study suggests that the Frankia-alder symbiosis is a promising (and a compatible) plant-microorganism association for the revegetation of contaminated sites, with minimal risk of metal dispersion.
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Affiliation(s)
- Pier-Anne Bélanger
- Centre d'étude et de valorisation de la diversité microbienne, Département de Biologie, Université de Sherbrooke, Sherbrooke, Qc J1K 2R1, Canada
| | - Jean-Philippe Bellenger
- Centre d'étude et de valorisation de la diversité microbienne, Département de Chimie, Université de Sherbrooke, Sherbrooke, Qc J1K 2R1, Canada; Princeton Environmental Institute, Princeton University, Princeton, NJ 08544, USA
| | - Sébastien Roy
- Centre d'étude et de valorisation de la diversité microbienne, Département de Biologie, Université de Sherbrooke, Sherbrooke, Qc J1K 2R1, Canada.
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76
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Menkis A, Marčiulynas A, Gedminas A, Lynikienė J, Povilaitienė A. High-Throughput Sequencing Reveals Drastic Changes in Fungal Communities in the Phyllosphere of Norway Spruce (Picea abies) Following Invasion of the Spruce Bud Scale (Physokermes piceae). Microb Ecol 2015; 70:904-911. [PMID: 26054703 DOI: 10.1007/s00248-015-0638-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [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: 03/10/2015] [Accepted: 05/31/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to assess the diversity and composition of fungal communities in damaged and undamaged shoots of Norway spruce (Picea abies) following recent invasion of the spruce bud scale (Physokermes piceae) in Lithuania. Sampling was done in July 2013 and included 50 random lateral shoots from ten random trees in each of five visually undamaged and five damaged 40-50-year-old pure stands of P. abies. DNA was isolated from 500 individual shoots, subjected to amplification of the internal transcribed spacer of fungal ribosomal DNA (ITS rDNA), barcoded and sequenced. Clustering of 149,426 high-quality sequences resulted in 1193 non-singleton contigs of which 1039 (87.1 %) were fungal. In total, there were 893 fungal taxa in damaged shoots and 608 taxa in undamaged shoots (p < 0.0001). Furthermore, 431 (41.5 %) fungal taxa were exclusively in damaged shoots, 146 (14.0 %) were exclusively in undamaged shoots, and 462 (44.5 %) were common to both types of samples. Correspondence analysis showed that study sites representing damaged and undamaged shoots were separated from each other, indicating that in these fungal communities, these were largely different and, therefore, heavily affected by P. piceae. In conclusion, the results demonstrated that invasive alien tree pests may have a profound effect on fungal mycobiota associated with the phyllosphere of P. abies, and therefore, in addition to their direct negative effect owing physical damage of the tissue, they may also indirectly determine health, sustainability and, ultimately, distribution of the forest tree species.
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Affiliation(s)
- Audrius Menkis
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007, Uppsala, Sweden.
| | - Adas Marčiulynas
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, Girionys, LT-53101, Kaunas, Lithuania
| | - Artūras Gedminas
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, Girionys, LT-53101, Kaunas, Lithuania
| | - Jūratė Lynikienė
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, Girionys, LT-53101, Kaunas, Lithuania
| | - Aistė Povilaitienė
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, Girionys, LT-53101, Kaunas, Lithuania
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77
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Ambrosini VG, Voges JG, Canton L, Couto RDR, Ferreira PAA, Comin JJ, de Melo GWB, Brunetto G, Soares CRFS. Effect of arbuscular mycorrhizal fungi on young vines in copper-contaminated soil. Braz J Microbiol 2015; 46:1045-52. [PMID: 26691462 PMCID: PMC4704612 DOI: 10.1590/s1517-838246420140622] [Citation(s) in RCA: 27] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/09/2014] [Indexed: 11/29/2022] Open
Abstract
High copper (Cu) levels in uprooted old vineyard soils may cause toxicity in transplanted young vines, although such toxicity may be reduced by inoculating plants with arbuscular mycorrhizal fungi (AMF). The objective of this study was to evaluate the effects of AMF on the plant growth, chlorophyll contents, mycorrhizal colonization, and Cu and phosphorus (P) absorption in young vines cultivated in a vineyard soil contaminated by Cu. Commercial vineyard soil with high Cu levels was placed in plastic tubes and transplanted with young vines, which were inoculated with six AMF species (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus, R. irregularis) and a control treatment on randomized blocks with 12 replicates. After 130 days, the mycorrhizal colonization, root and shoot dry matter (DM), height increment, P and Cu absorption, and chlorophyll contents were evaluated. The height increment, shoot DM and chlorophyll contents were not promoted by AMF, although the root DM was increased by R. clarus and R. irregularis, which had the greatest mycorrhizal colonization and P uptake. AMF increased Cu absorption but decreased its transport to shoots. Thus, AMF species, particularly R. clarus and R. irregularis, contribute to the establishment of young vines exposed to high Cu levels.
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Affiliation(s)
| | | | - Ludiana Canton
- Universidade Federal de Santa Catarina, Florianópolis, SC,
Brazil
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78
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Ghosh P, Rathinasabapathi B, Ma LQ. Phosphorus solubilization and plant growth enhancement by arsenic-resistant bacteria. Chemosphere 2015; 134:1-6. [PMID: 25880602 DOI: 10.1016/j.chemosphere.2015.03.048] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [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: 02/05/2015] [Revised: 03/21/2015] [Accepted: 03/23/2015] [Indexed: 06/04/2023]
Abstract
Phosphorus is an essential nutrient, which is limited in most soils. The P solubilization and growth enhancement ability of seven arsenic-resistant bacteria (ARB), which were isolated from arsenic hyperaccumulator Pteris vittata, was investigated. Siderophore-producing ARB (PG4, 5, 6, 9, 10, 12 and 16) were effective in solubilizing P from inorganic minerals FePO4 and phosphate rock, and organic phytate. To reduce bacterial P uptake we used filter-sterilized Hoagland medium containing siderophores or phytase produced by PG12 or PG6 to grow tomato plants supplied with FePO4 or phytate. To confirm that siderophores were responsible for P release, we compared the mutants of siderophore-producing bacterium Pseudomonas fluorescens Pf5 (PchA) impaired in siderophore production with the wild type and test strains. After 7d of growth, mutant PchA solubilized 10-times less P than strain PG12, which increased tomato root biomass by 1.7 times. For phytate solubilization by PG6, tomato shoot biomass increased by 44% than control bacterium Pseudomonas chlororaphis. P solubilization by ARB from P. vittata may be useful in enhancing plant growth and nutrition in other crop plants.
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Affiliation(s)
- Piyasa Ghosh
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States
| | - Bala Rathinasabapathi
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, United States
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States.
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79
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Burra DD, Mühlenbock P, Andreasson E. Salicylic and jasmonic acid pathways are necessary for defence against Dickeya solani as revealed by a novel method for Blackleg disease screening of in vitro grown potato. Plant Biol (Stuttg) 2015; 17:1030-1038. [PMID: 25903921 DOI: 10.1111/plb.12339] [Citation(s) in RCA: 13] [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: 02/18/2015] [Accepted: 04/20/2015] [Indexed: 06/04/2023]
Abstract
Potato is major crop ensuring food security in Europe, and blackleg disease is increasingly causing losses in yield and during storage. Recently, one blackleg pathogen, Dickeya solani has been shown to be spreading in Northern Europe that causes aggressive disease development. Currently, identification of tolerant commercial potato varieties has been unsuccessful; this is confounded by the complicated etiology of the disease and a strong environmental influence on disease development. There is currently a lack of efficient testing systems. Here, we describe a system for quantification of blackleg symptoms on shoots of sterile in vitro potato plants, which saves time and space compared to greenhouse and existing field assays. We found no evidence for differences in infection between the described in vitro-based screening method and existing greenhouse assays. This system facilitates efficient screening of blackleg disease response of potato plants independent of other microorganisms and variable environmental conditions. We therefore used the in vitro screening method to increase understanding of plant mechanisms involved in blackleg disease development by analysing disease response of hormone- related (salicylic and jasmonic acid) transgenic potato plants. We show that both jasmonic (JA) and salicylic (SA) acid pathways regulate tolerance to blackleg disease in potato, a result unlike previous findings in Arabidopsis defence response to necrotrophic bacteria. We confirm this by showing induction of a SA marker, pathogenesis-related protein 1 (StPR1), and a JA marker, lipoxygenase (StLOX), in Dickeya solani infected in vitro potato plants. We also observed that tubers of transgenic potato plants were more susceptible to soft rot compared to wild type, suggesting a role for SA and JA pathways in general tolerance to Dickeya.
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Affiliation(s)
- D D Burra
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - P Mühlenbock
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - E Andreasson
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
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80
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Abdollahi H, Ghahremani Z, Erfaninia K, Mehrabi R. Role of electron transport chain of chloroplasts in oxidative burst of interaction between Erwinia amylovora and host cells. Photosynth Res 2015; 124:231-242. [PMID: 25820489 DOI: 10.1007/s11120-015-0127-8] [Citation(s) in RCA: 3] [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] [Received: 01/12/2015] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
Erwinia amylovora is a necrogenic bacterium, causing the fire blight disease on many rosaceous plants. Triggering oxidative burst by E. amylovora is a key response by which host plants try to restrain pathogen spread. Electron transport chain (ETC) of chloroplasts is known as an inducible source of reactive oxygen species generation in various stresses. This research was performed to assess the role of this ETC in E. amylovora-host interaction using several inhibitors of this chain in susceptible and resistant apple and pear genotypes. All ETC inhibitors delayed appearance of disease necrosis, but the effects of methyl viologen, glutaraldehyde, and DCMU were more significant. In the absence of inhibitors, resistant genotypes showed an earlier and severe H2O2 generation and early suppression of redox dependent, psbA gene. The effects of inhibitors were corresponding to the redox potential of ETC inhibitory sites. In addition, delayed necrosis appearance was associated with the decreased disease severity and delayed H2O2 generation. These results provide evidences for the involvement of this ETC in host oxidative burst and suggest that chloroplast ETC has significant role in E. amylovora-host interaction.
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Affiliation(s)
- Hamid Abdollahi
- Horticulture Research Department, Seed and Plant Improvement Institute, Karaj, Iran,
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81
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Labidi S, Jeddi FB, Tisserant B, Yousfi M, Sanaa M, Dalpé Y, Sahraoui ALH. Field application of mycorrhizal bio-inoculants affects the mineral uptake of a forage legume (Hedysarum coronarium L.) on a highly calcareous soil. Mycorrhiza 2015; 25:297-309. [PMID: 25323044 DOI: 10.1007/s00572-014-0609-0] [Citation(s) in RCA: 6] [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] [Received: 07/03/2014] [Accepted: 10/03/2014] [Indexed: 06/04/2023]
Abstract
The efficiency of two mycorrhizal bio-inoculants on the mineral uptake during the growth stages of a Mediterranean forage legume sulla (Hedysarum coronarium L.) was studied in the field on a highly calcareous soil. The first inoculum (Mm) was made up of a mixture of native arbuscular mycorrhizal fungi (AMF) isolated from calcareous soils: Septoglomus constrictum, Funneliformis geosporum, Glomus fuegianum, Rhizophagus irregularis and Glomus sp. The second was a commercial inoculum (Mi) containing one AMF species: R. irregularis. Both mycorrhizal inoculants increased total and arbuscular colonization of sulla roots. Inoculation with Mm showed a positive effect on sulla shoot dry weight (SDW) when compared to Mi and non-inoculated plants (control). Mineral contents (P, Mg, Mn, Fe) were higher in the shoots of sulla plants cultivated on mycorrhiza-inoculated plots compared to non-inoculated ones. This enhancement was observed during the flowering stage for P, Mg and Mn and during the rosette stage for Fe. An increase in P content of 50 % in plants inoculated with Mm compared to non-inoculated ones may be explained by the induction of root alkaline and acid phosphatase activities. Higher efficiency of native AMF species adapted to calcareous soils opens the way towards the development of mycorrhiza bio-fertilizers targeted to improve sustainable fertilization management in such soils.
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Affiliation(s)
- S Labidi
- Laboratoire des Sciences Horticoles, Institut National Agronomique de Tunisie, Université de Carthage, 43 Ave Charles Nicolle, 1082, Tunis, Mahrajène, Tunisie
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82
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Cattani I, Beone GM, Gonnelli C. Influence of Rhizophagus irregularis inoculation and phosphorus application on growth and arsenic accumulation in maize (Zea mays L.) cultivated on an arsenic-contaminated soil. Environ Sci Pollut Res Int 2015; 22:6570-6577. [PMID: 25716900 DOI: 10.1007/s11356-014-3837-0] [Citation(s) in RCA: 5] [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] [Received: 06/10/2014] [Accepted: 11/10/2014] [Indexed: 06/04/2023]
Abstract
Southern Tuscany (Italy) is characterized by extensive arsenic (As) anomalies, with concentrations of up to 2000 mg kg soil(-1). Samples from the location of Scarlino, containing about 200 mg kg(-1) of As, were used to study the influence of the inoculation of an arbuscular mycorrhizal (AM) fungus (Rhizophagus irregularis, previously known as Glomus intraradices) and of phosphorus (P) application, separately and in combination, on As speciation in the rhizosphere of Zea mays on plant growth and As accumulation. Also, P distribution in plant parts was investigated. Each treatment produced a moderate rise of As(III) in the rhizosphere, increased As(III) and lowered As(V) concentration in shoots. P treatment, alone or in combination with AM, augmented the plant biomass. The treatments did not affect total As concentration in the shoots (with all the values <1 mg kg(-1) dry weight), while in the roots it was lowered by P treatment alone. Such decrease was probably a consequence of the competition between P and As(V) for the same transport systems, interestingly nullified by the combination with AM treatment. P concentration was higher with AM only in both shoots and roots. Therefore, the obtained results can be extremely encouraging for maize cultivation on a marginal land, like the one studied.
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Affiliation(s)
- I Cattani
- Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Via Emilia Parmense, 84, 27100, Piacenza, Italy,
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83
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Boava LP, Sagawa CHD, Cristofani-Yaly M, Machado MA. Incidence of 'Candidatus Liberibacter asiaticus'-Infected Plants Among Citrandarins as Rootstock and Scion Under Field Conditions. Phytopathology 2015; 105:518-524. [PMID: 25423067 DOI: 10.1094/phyto-08-14-0211-r] [Citation(s) in RCA: 6] [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: 06/04/2023]
Abstract
Huanglongbing (HLB), caused by the bacterium 'Candidatus Liberibacter' spp., is currently one of the most serious diseases of citrus plants and has caused substantial economic losses. Thus far, there is no source of genetic resistance to HLB in the genus Citrus or its relatives. However, several studies have reported Poncirus trifoliata and some of its hybrids to be more tolerant to the disease. The main objective of this study was to report differences in the incidence of 'Ca. L. asiaticus' infection in citrandarin plants, hybrids from Sunki mandarin (Citrus sunki (Hayata) hort. ex Tanaka), and trifoliate orange Rubidoux (P. trifoliata (L.) Raf.)), after conducting an extensive survey under field conditions. These hybrid plants were established for approximately 7 years in an area with a high incidence of 'Ca. L. asiaticus'-infected plants. We selected two experimental areas (area A and area B), located approximately 10 m apart. Area A consists of Pera sweet orange (C. sinensis (L.) Osb.) grafted onto 56 different citrandarin rootstocks. Area B consists of citrandarin scions grafted onto Rangpur lime (C. limonia Osb.) rootstock. Bacteria in the leaves and roots were detected using real-time quantitative polymerase chain reaction. The incidence of 'Ca. L. asiaticus'-infected plants was 92% in area A and 14% in area B. Because infected plants occurred in both areas, we examined whether the P. trifoliata hybrid rootstock influenced HLB development and also determined the distribution of 'Ca. L. asiaticus' in Citrus tree tissues. Although this survey does not present evidence regarding the resistance of P. trifoliata and its hybrids in relation to bacteria or psyllids, future investigation, mainly using the most promising hybrids for response to 'Ca. L. asiaticus', will help us to understand the probable mechanism of defense or identifying compounds in P. trifoliata and its hybrids that are very important as strategy to combat HLB. Details of these results are presented and discussed in this article.
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Affiliation(s)
- Leonardo Pires Boava
- Centro de Citricultura Sylvio Moreira, CP4, 13490-970, Cordeirópolis-São Paulo, Brazil
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84
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Bennett AE, Grussu D, Kam J, Caul S, Halpin C. Plant lignin content altered by soil microbial community. New Phytol 2015; 206:166-174. [PMID: 25389017 DOI: 10.1111/nph.13171] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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: 08/11/2014] [Accepted: 10/13/2014] [Indexed: 06/04/2023]
Abstract
Questions have been raised in various fields of research about the consequences of plants with modified lignin production. As a result of their roles in nutrient cycling and plant diversity, plant-soil interactions should be a major focus of ecological studies on lignin-modified plants. However, most studies have been decomposition studies conducted in a single soil or in sterile soil. Thus, we understand little about plant-soil interactions in living lignin-modified plants. In lignin mutants of three different barley (Hordeum vulgare) cultivars and their corresponding wild-types associated with three different soil microbial communities, we asked: do plant-soil microbiome interactions influence the lignin content of plants?; does a mutation in lignin production alter the outcome of plant-soil microbiome interactions?; does the outcome of plant-soil microbiome interactions depend on host genotype or the presence of a mutation altering lignin production? In roots, the soil community explained 6% of the variation in lignin content, but, in shoots, the soil community explained 21% of the variation in lignin content and was the only factor influencing lignin content. Neither genotype nor mutations in lignin production explained associations with fungi. Lignin content changes in response to a plant's soil microbial community, and may be a defensive response to particular components of the soil community.
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Affiliation(s)
- Alison E Bennett
- Ecological Sciences, James Hutton Institute, Errol Road, Invergowrie, Dundee, DD2 5DA, UK
| | - Dominic Grussu
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Errol Road, Invergowrie, Dundee, DD2 5DA, UK
| | - Jason Kam
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Errol Road, Invergowrie, Dundee, DD2 5DA, UK
| | - Sandra Caul
- Ecological Sciences, James Hutton Institute, Errol Road, Invergowrie, Dundee, DD2 5DA, UK
| | - Claire Halpin
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Errol Road, Invergowrie, Dundee, DD2 5DA, UK
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85
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Lu YF, Lu M. Remediation of PAH-contaminated soil by the combination of tall fescue, arbuscular mycorrhizal fungus and epigeic earthworms. J Hazard Mater 2015; 285:535-541. [PMID: 25534968 DOI: 10.1016/j.jhazmat.2014.07.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [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: 03/29/2014] [Revised: 07/09/2014] [Accepted: 07/12/2014] [Indexed: 06/04/2023]
Abstract
A 120-day experiment was performed to investigate the effect of a multi-component bioremediation system consisting of tall fescue (Festuca arundinacea), arbuscular mycorrhizal fungus (AMF) (Glomus caledoniun L.), and epigeic earthworms (Eisenia foetida) for cleaning up polycyclic aromatic hydrocarbons (PAHs)-contaminated soil. Inoculation with AMF and/or earthworms increased plant yield and PAH accumulation in plants. However, PAH uptake by tall fescue accounted for a negligible portion of soil PAH removal. Mycorrhizal tall fescue significantly enhanced PAH dissipation, PAH degrader density and polyphenol oxidase activity in soil. The highest PAH dissipation (93.4%) was observed in the combination treatment: i.e., AMF+earthworms+tall fescue, in which the soil PAH concentration decreased from an initial value of 620 to 41 mg kg(-1) in 120 days. This concentration is below the threshold level required for Chinese soil PAH quality (45 mg kg(-1) dry weight) for residential use.
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Affiliation(s)
- Yan-Fei Lu
- School of Information and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
| | - Mang Lu
- School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, China
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86
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Eaton CJ, Dupont PY, Solomon P, Clayton W, Scott B, Cox MP. A Core Gene Set Describes the Molecular Basis of Mutualism and Antagonism in Epichloë spp. Mol Plant Microbe Interact 2015; 28:218-31. [PMID: 25496592 DOI: 10.1094/mpmi-09-14-0293-fi] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Beneficial plant-fungal interactions play an important role in the ability of plants to survive changing environmental conditions. In contrast, phytopathogenic fungi fall at the opposite end of the symbiotic spectrum, causing reduced host growth or even death. In order to exploit beneficial interactions and prevent pathogenic ones, it is essential to understand the molecular differences underlying these alternative states. The association between the endophyte Epichloë festucae and Lolium perenne (perennial ryegrass) is an excellent system for studying these molecular patterns due to the existence of several fungal mutants that have an antagonistic rather than a mutualistic interaction with the host plant. By comparing gene expression in a wild-type beneficial association with three mutant antagonistic associations disrupted in key signaling genes, we identified a core set of 182 genes that show common differential expression patterns between these two states. These gene expression changes are indicative of a nutrient-starvation response, as supported by the upregulation of genes encoding degradative enzymes, transporters, and primary metabolism, and downregulation of genes encoding putative small-secreted proteins and secondary metabolism. These results suggest that disruption of a mutualistic symbiotic interaction may lead to an elevated uptake and degradation of host-derived nutrients and cell-wall components, reminiscent of phytopathogenic interactions.
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87
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Vahabi K, Sherameti I, Bakshi M, Mrozinska A, Ludwig A, Reichelt M, Oelmüller R. The interaction of Arabidopsis with Piriformospora indica shifts from initial transient stress induced by fungus-released chemical mediators to a mutualistic interaction after physical contact of the two symbionts. BMC Plant Biol 2015; 15:58. [PMID: 25849363 PMCID: PMC4384353 DOI: 10.1186/s12870-015-0419-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [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: 10/03/2014] [Accepted: 01/08/2015] [Indexed: 05/19/2023]
Abstract
BACKGROUND Piriformospora indica, an endophytic fungus of Sebacinales, colonizes the roots of many plant species including Arabidopsis thaliana. The symbiotic interaction promotes plant performance, growth and resistance/tolerance against abiotic and biotic stress. RESULTS We demonstrate that exudated compounds from the fungus activate stress and defense responses in the Arabidopsis roots and shoots before the two partners are in physical contact. They induce stomata closure, stimulate reactive oxygen species (ROS) production, stress-related phytohormone accumulation and activate defense and stress genes in the roots and/or shoots. Once a physical contact is established, the stomata re-open, ROS and phytohormone levels decline, and the number and expression level of defense/stress-related genes decreases. CONCLUSIONS We propose that exudated compounds from P. indica induce stress and defense responses in the host. Root colonization results in the down-regulation of defense responses and the activation of genes involved in promoting plant growth, metabolism and performance.
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Affiliation(s)
- Khabat Vahabi
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Irena Sherameti
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Madhunita Bakshi
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Anna Mrozinska
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Anatoli Ludwig
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Michael Reichelt
- />Max-Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Ralf Oelmüller
- />Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
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88
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Mendoza RE, García IV, de Cabo L, Weigandt CF, Fabrizio de Iorio A. The interaction of heavy metals and nutrients present in soil and native plants with arbuscular mycorrhizae on the riverside in the Matanza-Riachuelo River Basin (Argentina). Sci Total Environ 2015; 505:555-564. [PMID: 25461058 DOI: 10.1016/j.scitotenv.2014.09.105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 05/22/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
This study assessed the contamination by heavy metals (Cr, Cu, Pb, Zn), and nutrients (N, P) in soils and native plants, and the effect of the concentration of those elements with the density of arbuscular-mycorrhizal (AM) spores in soil and colonization in roots from the riverside of the Matanza-Riachuelo River Basin (MRRB). The concentration of metals and nutrients in soils and plants (Eleocharis montana, Cyperus eragrostis, Hydrocotyle bonariensis) increased from the upper sites (8 km from headwaters) to the lower sites (6 km from the mouth of the Riachuelo River) of the basin. AM-colonization on the roots of H. bonariensis and spore density in soil decreased as the concentrations of metals in soil and plant tissues increased from the upper to lower sites of the basin within a consistent gradient of contamination associated with land use, soil disturbance, population, and chemicals discharged into the streams and rivers along the MRRB. The general trends for all metals in plant tissue were to have highest concentrations in roots, then in rhizomes and lowest in aerial biomass. The translocation (TF) and bioconcentration (BCF) factors decreased in plants which grow from the upper sites to the lower sites of the basin. The plants tolerated a wide range in type and quantity of contamination along the basin by concentrating more metals and nutrients in roots than in aboveground tissue. The AM spore density in soil and colonization in roots of H. bonariensis decreased with the increase of the degree of contamination (Dc) in soil.
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Affiliation(s)
- Rodolfo E Mendoza
- Departamento de Ecología, Nutrición Vegetal y Micorrizas Arbusculares, Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN-CONICET), Av. Ángel Gallardo 470, C1405DJR Ciudad de Buenos Aires, Argentina.
| | - Ileana V García
- Departamento de Ecología, Nutrición Vegetal y Micorrizas Arbusculares, Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN-CONICET), Av. Ángel Gallardo 470, C1405DJR Ciudad de Buenos Aires, Argentina
| | - Laura de Cabo
- Departamento de Ecología, Nutrición Vegetal y Micorrizas Arbusculares, Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN-CONICET), Av. Ángel Gallardo 470, C1405DJR Ciudad de Buenos Aires, Argentina
| | - Cristian F Weigandt
- Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Ciudad de Buenos Aires, Argentina
| | - Alicia Fabrizio de Iorio
- Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Ciudad de Buenos Aires, Argentina
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89
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Ortiz N, Armada E, Duque E, Roldán A, Azcón R. Contribution of arbuscular mycorrhizal fungi and/or bacteria to enhancing plant drought tolerance under natural soil conditions: effectiveness of autochthonous or allochthonous strains. J Plant Physiol 2015; 174:87-96. [PMID: 25462971 DOI: 10.1016/j.jplph.2014.08.019] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [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: 04/24/2014] [Revised: 08/05/2014] [Accepted: 08/22/2014] [Indexed: 05/20/2023]
Abstract
Autochthonous microorganisms [a consortium of arbuscular-mycorrhizal (AM) fungi and Bacillus thuringiensis (Bt)] were assayed and compared to Rhizophagus intraradices (Ri), Bacillus megaterium (Bm) or Pseudomonas putida (Psp) and non-inoculation on Trifolium repens in a natural arid soil under drought conditions. The autochthonous bacteria Bt and the allochthonous bacteria Psp increased nutrients and the relative water content and decreased stomatal conductance, electrolyte leakage, proline and APX activity, indicating their abilities to alleviate the drought stress. Mycorrhizal inoculation significantly enhanced plant growth, nutrient uptake and the relative water content, particularly when associated with specific bacteria minimizing drought stress-imposed effects. Specific combinations of autochthonous or allochthonous inoculants also contributed to plant drought tolerance by changing proline and antioxidative activities. However, non-inoculated plants had low relative water and nutrients contents, shoot proline accumulation and glutathione reductase activity, but the highest superoxide dismutase activity, stomatal conductance and electrolyte leakage. Microbial activities irrespective of the microbial origin seem to be coordinately functioning in the plant as an adaptive response to modulated water stress tolerance and minimizing the stress damage. The autochthonous AM fungi with Bt or Psp and those allochthonous Ri with Bm or Psp inoculants increased water stress alleviation. The autochthonous Bt showed the greatest ability to survive under high osmotic stress compared to the allochthonous strains, but when single inoculated or associated with Ri or AM fungi were similarly efficient in terms of physiological and nutritional status and in increasing plant drought tolerance, attenuating and compensating for the detrimental effect of water limitation.
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Affiliation(s)
- N Ortiz
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain
| | - E Armada
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain
| | - E Duque
- Departamento de Proteccion Ambiental, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain
| | - A Roldán
- Department of Soil and Water Conservation, Centro de Edafología y Biología Aplicada del Segura, CSIC, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain
| | - R Azcón
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
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90
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Teste FP, Veneklaas EJ, Dixon KW, Lambers H. Is nitrogen transfer among plants enhanced by contrasting nutrient-acquisition strategies? Plant Cell Environ 2015; 38:50-60. [PMID: 24811370 DOI: 10.1111/pce.12367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [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: 02/10/2014] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 06/03/2023]
Abstract
Nitrogen (N) transfer among plants has been found where at least one plant can fix N2 . In nutrient-poor soils, where plants with contrasting nutrient-acquisition strategies (without N2 fixation) co-occur, it is unclear if N transfer exists and what promotes it. A novel multi-species microcosm pot experiment was conducted to quantify N transfer between arbuscular mycorrhizal (AM), ectomycorrhizal (EM), dual AM/EM, and non-mycorrhizal cluster-rooted plants in nutrient-poor soils with mycorrhizal mesh barriers. We foliar-fed plants with a K(15) NO3 solution to quantify one-way N transfer from 'donor' to 'receiver' plants. We also quantified mycorrhizal colonization and root intermingling. Transfer of N between plants with contrasting nutrient-acquisition strategies occurred at both low and high soil nutrient levels with or without root intermingling. The magnitude of N transfer was relatively high (representing 4% of donor plant N) given the lack of N2 fixation. Receiver plants forming ectomycorrhizas or cluster roots were more enriched compared with AM-only plants. We demonstrate N transfer between plants of contrasting nutrient-acquisition strategies, and a preferential enrichment of cluster-rooted and EM plants compared with AM plants. Nutrient exchanges among plants are potentially important in promoting plant coexistence in nutrient-poor soils.
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Affiliation(s)
- François P Teste
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley (Perth), Western Australia, 6009, Australia
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91
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Truong HN, Thalineau E, Bonneau L, Fournier C, Potin S, Balzergue S, VAN Tuinen D, Jeandroz S, Morandi D. The Medicago truncatula hypermycorrhizal B9 mutant displays an altered response to phosphate and is more susceptible to Aphanomyces euteiches. Plant Cell Environ 2015; 38:73-88. [PMID: 24815324 DOI: 10.1111/pce.12370] [Citation(s) in RCA: 5] [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: 02/20/2014] [Revised: 04/29/2014] [Accepted: 04/30/2014] [Indexed: 05/13/2023]
Abstract
Inorganic phosphate (Pi) plays a key role in the development of arbuscular mycorrhizal (AM) symbiosis, which is favoured when Pi is limiting in the environment. We have characterized the Medicago truncatula hypermycorrhizal B9 mutant for its response to limiting (P/10) and replete (P2) Pi. On P2, mycorrhization was significantly higher in B9 plants than in wild-type (WT). The B9 mutant displayed hallmarks of Pi-limited plants, including higher levels of anthocyanins and lower concentrations of Pi in shoots than WT plants. Transcriptome analyses of roots of WT and B9 plants cultivated on P2 or on P/10 confirmed the Pi-limited profile of the mutant on P2 and highlighted its altered response to Pi on P/10. Furthermore, the B9 mutant displayed a higher expression of defence/stress-related genes and was more susceptible to infection by the root oomycete pathogen Aphanomyces euteiches than WT plants. We propose that the hypermycorrhizal phenotype of the B9 mutant is linked to its Pi-limited status favouring AM symbiosis in contrast to WT plants in Pi-replete conditions, and discuss the possible links between the altered response of the B9 mutant to Pi, mycorrhization and infection by A. euteiches.
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Affiliation(s)
- Hoai-Nam Truong
- INRA/AgroSup/Université de Bourgogne UMR1347 Agroécologie, ERL CNRS 6300, Dijon, F-21065, France
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92
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Beck M, Wyrsch I, Strutt J, Wimalasekera R, Webb A, Boller T, Robatzek S. Expression patterns of flagellin sensing 2 map to bacterial entry sites in plant shoots and roots. J Exp Bot 2014; 65:6487-98. [PMID: 25205577 PMCID: PMC4246182 DOI: 10.1093/jxb/eru366] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [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: 05/18/2023]
Abstract
Pathogens can colonize all plant organs and tissues. To prevent this, each cell must be capable of autonomously triggering defence. Therefore, it is generally assumed that primary sensors of the immune system are constitutively present. One major primary sensor against bacterial infection is the flagellin sensing 2 (FLS2) pattern recognition receptor (PRR). To gain insights into its expression pattern, the FLS2 promoter activity in β-glucuronidase (GUS) reporter lines was monitored. The data show that pFLS2::GUS activity is highest in cells and tissues vulnerable to bacterial entry and colonization, such as stomata, hydathodes, and lateral roots. GUS activity is also high in the vasculature and, by monitoring Ca(2+) responses in the vasculature, it was found that this tissue contributes to flg22-induced Ca(2+) burst. The FLS2 promoter is also regulated in a tissue- and cell type-specific manner and is responsive to hormones, damage, and biotic stresses. This results in stimulus-dependent expansion of the FLS2 expression domain. In summary, a tissue- and cell type-specific map of FLS2 expression has been created correlating with prominent entry sites and target tissues of plant bacterial pathogens.
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Affiliation(s)
- Martina Beck
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Ines Wyrsch
- Zürich-Basel Plant Science Center, University of Basel, Department of Environmental Sciences, Botany, Basel, Switzerland
| | - James Strutt
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
| | - Rinukshi Wimalasekera
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Alex Webb
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Thomas Boller
- Zürich-Basel Plant Science Center, University of Basel, Department of Environmental Sciences, Botany, Basel, Switzerland
| | - Silke Robatzek
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
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93
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Chandrasekaran M, Boughattas S, Hu S, Oh SH, Sa T. A meta-analysis of arbuscular mycorrhizal effects on plants grown under salt stress. Mycorrhiza 2014; 24:611-25. [PMID: 24770494 DOI: 10.1007/s00572-014-0582-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/11/2014] [Indexed: 05/03/2023]
Abstract
Salt stress limits crop yield and sustainable agriculture in most arid and semiarid regions of the world. Arbuscular mycorrhizal fungi (AMF) are considered bio-ameliorators of soil salinity tolerance in plants. In evaluating AMF as significant predictors of mycorrhizal ecology, precise quantifiable changes in plant biomass and nutrient uptake under salt stress are crucial factors. Therefore, the objective of the present study was to analyze the magnitude of the effects of AMF inoculation on growth and nutrient uptake of plants under salt stress through meta-analyses. For this, data were compared in the context of mycorrhizal host plant species, plant family and functional group, herbaceous vs. woody plants, annual vs. perennial plants, and the level of salinity across 43 studies. Results indicate that, under saline conditions, AMF inoculation significantly increased total, shoot, and root biomass as well as phosphorous (P), nitrogen (N), and potassium (K) uptake. Activities of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase also increased significantly in mycorrhizal compared to nonmycorrhizal plants growing under salt stress. In addition, sodium (Na) uptake decreased significantly in mycorrhizal plants, while changes in proline accumulation were not significant. Across most subsets of the data analysis, identities of AMF (Glomus fasciculatum) and host plants (Acacia nilotica, herbs, woody and perennial) were found to be essential in understanding plant responses to salinity stress. For the analyzed dataset, it is concluded that under salt stress, mycorrhizal plants have extensive root traits and mycorrhizal morphological traits which help the uptake of more P and K, together with the enhanced production of antioxidant enzymes resulting in salt stress alleviation and increased plant biomass.
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Affiliation(s)
- Murugesan Chandrasekaran
- Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea
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94
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Lindow S, Olson W, Buchner R. Colonization of Dormant Walnut Buds by Xanthomonas arboricola pv. juglandis Is Predictive of Subsequent Disease. Phytopathology 2014; 104:1163-1174. [PMID: 25338268 DOI: 10.1094/phyto-01-14-0001-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The potential role of walnut buds as a driver of walnut blight disease, caused by Xanthomonas arboricola pv. juglandis, was addressed by quantifying its temporal dynamics in a large number of orchards in California. The abundance of X. arboricola pv. juglandis on individual dormant and developing buds and shoots of walnut trees varied by >10(6)-fold at any sample time and within a given tree. X. arboricola pv. juglandis population size in shoots was often no larger than that in the buds from which the shoots were derived but was strongly correlated with prior pathogen population sizes in buds. X. arboricola pv. juglandis populations on developing nuts were strongly related to that on the shoots on which they were borne. The incidence of disease of nuts in June was strongly correlated with the logarithm of the population size of X. arboricola pv. juglandis in dormant buds in March. Inoculum efficiency, the slope of this linear relationship, varied between years but was strongly related to the number of rain events following bud break in each year. Thus, inoculum of X. arboricola pv. juglandis present on dormant buds is the primary determinant of nut infections and the risk of disease can be predicted from both the numbers of X. arboricola pv. juglandis in buds and the incidence of early spring rain.
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95
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Ghosh S, Gupta SK, Jha G. Identification and functional analysis of AG1-IA specific genes of Rhizoctonia solani. Curr Genet 2014; 60:327-41. [PMID: 25070039 DOI: 10.1007/s00294-014-0438-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [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: 03/27/2014] [Revised: 07/10/2014] [Accepted: 07/10/2014] [Indexed: 11/24/2022]
Abstract
Rhizoctonia solani is an important necrotrophic fungal pathogen which causes disease on diverse plant species. It has been classified into 14 genetically distinct anastomosis groups (AGs), however, very little is known about their genomic diversity. AG1-IA causes sheath blight disease in rice and controlling this disease remains a challenge for sustainable rice cultivation. Recently the draft genome sequences of AG1-IA (rice isolate) and AG1-IB (lettuce isolate) had become publicly available. In this study, using comparative genomics, we report identification of 3,942 R. solani genes that are uniquely present in AG1-IA. Many of these genes encode important biological, molecular functions and exhibit dynamic expression during in-planta growth of the pathogen in rice. Based upon sequence similarity with genes that are required for plant and human/zoonotic diseases, we identified several putative virulence/pathogenicity determinants amongst AG1-IA specific genes. While studying the expression of 19 randomly selected genes, we identified three genes highly up-regulated during in-planta growth. The detailed in silico characterization of these genes and extent of their up-regulation in different rice genotypes, having variable degree of disease susceptibility, suggests their importance in rice-Rhizoctonia interactions. In summary, the present study reports identification, functional characterization of AG1-IA specific genes and predicts important virulence determinants that might enable the pathogen to grow inside hostile plant environment. Further characterization of these genes would shed useful insights about the pathogenicity mechanism of AG1-IA on rice.
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Affiliation(s)
- Srayan Ghosh
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
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96
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Kariman K, Barker SJ, Finnegan PM, Tibbett M. Ecto- and arbuscular mycorrhizal symbiosis can induce tolerance to toxic pulses of phosphorus in jarrah (Eucalyptus marginata) seedlings. Mycorrhiza 2014; 24:501-9. [PMID: 24584781 PMCID: PMC4156786 DOI: 10.1007/s00572-014-0567-6] [Citation(s) in RCA: 7] [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: 09/25/2013] [Accepted: 02/06/2014] [Indexed: 05/20/2023]
Abstract
In common with many plants native to low P soils, jarrah (Eucalyptus marginata) develops toxicity symptoms upon exposure to elevated phosphorus (P). Jarrah plants can establish arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations, along with a non-colonizing symbiosis described recently. AM colonization is known to influence the pattern of expression of genes required for P uptake of host plants and our aim was to investigate this phenomenon in relation to P sensitivity. Therefore, we examined the effect on hosts of the presence of AM and ECM fungi in combination with toxic pulses of P and assessed possible correlations between the induced tolerance and the shoot P concentration. The P transport dynamics of AM (Rhizophagus irregularis and Scutellospora calospora), ECM (Scleroderma sp.), non-colonizing symbiosis (Austroboletus occidentalis), dual mycorrhizal (R. irregularis and Scleroderma sp.), and non-mycorrhizal (NM) seedlings were monitored following two pulses of P. The ECM and A. occidentalis associations significantly enhanced the shoot P content of jarrah plants growing under P-deficient conditions. In addition, S. calospora, A. occidentalis, and Scleroderma sp. all stimulated plant growth significantly. All inoculated plants had significantly lower phytotoxicity symptoms compared to NM controls 7 days after addition of an elevated P dose (30 mg P kg(-1) soil). Following exposure to toxicity-inducing levels of P, the shoot P concentration was significantly lower in R. irregularis-inoculated and dually inoculated plants compared to NM controls. Although all inoculated plants had reduced toxicity symptoms and there was a positive linear relationship between rank and shoot P concentration, the protective effect was not necessarily explained by the type of fungal association or the extent of mycorrhizal colonization.
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Affiliation(s)
- Khalil Kariman
- School of Earth and Environment M087, The University of Western Australia, Crawley, WA 6009 Australia
- School of Plant Biology M084, The University of Western Australia, Crawley, WA 6009 Australia
| | - Susan J. Barker
- School of Plant Biology M084, The University of Western Australia, Crawley, WA 6009 Australia
- Institute of Agriculture M082, The University of Western Australia, Crawley, WA 6009 Australia
| | - Patrick M. Finnegan
- School of Plant Biology M084, The University of Western Australia, Crawley, WA 6009 Australia
- Institute of Agriculture M082, The University of Western Australia, Crawley, WA 6009 Australia
| | - Mark Tibbett
- School of Earth and Environment M087, The University of Western Australia, Crawley, WA 6009 Australia
- Department of Environmental Science and Technology (B37), School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire, MK 43 OAL England
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97
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Nikolov LA, Tomlinson PB, Manickam S, Endress PK, Kramer EM, Davis CC. Holoparasitic Rafflesiaceae possess the most reduced endophytes and yet give rise to the world's largest flowers. Ann Bot 2014; 114:233-42. [PMID: 24942001 PMCID: PMC4111398 DOI: 10.1093/aob/mcu114] [Citation(s) in RCA: 14] [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: 01/21/2014] [Accepted: 05/02/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Species in the holoparasitic plant family Rafflesiaceae exhibit one of the most highly modified vegetative bodies in flowering plants. Apart from the flower shoot and associated bracts, the parasite is a mycelium-like endophyte living inside their grapevine hosts. This study provides a comprehensive treatment of the endophytic vegetative body for all three genera of Rafflesiaceae (Rafflesia, Rhizanthes and Sapria), and reports on the cytology and development of the endophyte, including its structural connection to the host, shedding light on the poorly understood nature of this symbiosis. METHODS Serial sectioning and staining with non-specific dyes, periodic-Schiff's reagent and aniline blue were employed in order to characterize the structure of the endophyte across a phylogenetically diverse sampling. KEY RESULTS A previously identified difference in the nuclear size between Rafflesiaceae endophytes and their hosts was used to investigate the morphology and development of the endophytic body. The endophytes generally comprise uniseriate filaments oriented radially within the host root. The emergence of the parasite from the host during floral development is arrested in some cases by an apparent host response, but otherwise vegetative growth does not appear to elicit suppression by the host. CONCLUSIONS Rafflesiaceae produce greatly reduced and modified vegetative bodies even when compared with the other holoparasitic angiosperms once grouped with Rafflesiaceae, which possess some vegetative differentiation. Based on previous studies of seeds together with these findings, it is concluded that the endophyte probably develops directly from a proembryo, and not from an embryo proper. Similarly, the flowering shoot arises directly from the undifferentiated endophyte. These filaments produce a protocorm in which a shoot apex originates endogenously by formation of a secondary morphological surface. This degree of modification to the vegetative body is exceptional within angiosperms and warrants additional investigation. Furthermore, the study highlights a mechanical isolation mechanism by which the host may defend itself from the parasite.
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Affiliation(s)
- Lachezar A Nikolov
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Cambridge, MA 02138, USA
| | - P B Tomlinson
- The Kampong, National Tropical Botanical Garden, 4013 Douglas Road, Miami, FL 33133, USA
| | - Sugumaran Manickam
- Rimba Ilmu Botanic Garden, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia and
| | - Peter K Endress
- Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Elena M Kramer
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Cambridge, MA 02138, USA
| | - Charles C Davis
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Cambridge, MA 02138, USA
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98
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Teresani GR, Bertolini E, Alfaro-Fernández A, Martínez C, Tanaka FAO, Kitajima EW, Roselló M, Sanjuán S, Ferrándiz JC, López MM, Cambra M, Font MI. Association of 'Candidatus Liberibacter solanacearum' with a vegetative disorder of celery in Spain and development of a real-time PCR method for its detection. Phytopathology 2014; 104:804-811. [PMID: 24502203 DOI: 10.1094/phyto-07-13-0182-r] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new symptomatology was observed in celery (Apium graveolens) in Villena, Spain in 2008. Symptomatology included an abnormal amount of shoots per plant and curled stems. These vegetative disorders were associated with 'Candidatus Liberibacter solanacearum' and not with phytoplasmas. Samples from plant sap were immobilized on membranes based on the spot procedure and tested using a newly developed real-time polymerase chain reaction assay to detect 'Ca. L. solanacearum'. Then, a test kit was developed and validated by intralaboratory assays with an accuracy of 100%. Bacterial-like cells with typical morphology of 'Ca. Liberibacter' were observed using electron microscopy in celery plant tissues. A fifth haplotype of 'Ca. L. solanacearum', named E, was identified in celery and in carrot after analyzing partial sequences of 16S and 50S ribosomal RNA genes. From our results, celery (family Apiaceae) can be listed as a new natural host of this emerging bacterium.
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99
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Shehzadi M, Afzal M, Khan MU, Islam E, Mobin A, Anwar S, Khan QM. Enhanced degradation of textile effluent in constructed wetland system using Typha domingensis and textile effluent-degrading endophytic bacteria. Water Res 2014; 58:152-9. [PMID: 24755300 DOI: 10.1016/j.watres.2014.03.064] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [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: 11/16/2013] [Revised: 03/21/2014] [Accepted: 03/24/2014] [Indexed: 05/06/2023]
Abstract
Textile effluent is one of the main contributors of water pollution and it adversely affects fauna and flora. Constructed wetland is a promising approach to remediate the industrial effluent. The detoxification of industrial effluent in a constructed wetland system may be enhanced by applying beneficial bacteria that are able to degrade contaminants present in industrial effluent. The aim of this study was to evaluate the influence of inoculation of textile effluent-degrading endophytic bacteria on the detoxification of textile effluent in a vertical flow constructed wetland reactor. A wetland plant, Typha domingensis, was vegetated in reactor and inoculated with two endophytic bacterial strains, Microbacterium arborescens TYSI04 and Bacillus pumilus PIRI30. These strains possessed textile effluent-degrading and plant growth-promoting activities. Results indicated that bacterial inoculation improved plant growth, textile effluent degradation and mutagenicity reduction and were correlated with the population of textile effluent-degrading bacteria in the rhizosphere and endosphere of T. domingensis. Bacterial inoculation enhanced textile effluent-degrading bacterial population in rhizosphere, root and shoot of T. domingensis. Significant reductions in COD (79%), BOD (77%) TDS (59%) and TSS (27%) were observed by the combined use of plants and bacteria within 72 h. The resultant effluent meets the wastewater discharge standards of Pakistan and can be discharged into the environment without any risks. This study revealed that the combined use of plant and endophytic bacteria is one of the approaches to enhance textile effluent degradation in a constructed wetland system.
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Affiliation(s)
- Maryam Shehzadi
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
| | - Muhammad Afzal
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Muhammad Umar Khan
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
| | - Ejazul Islam
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
| | - Amina Mobin
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
| | - Samina Anwar
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
| | - Qaiser Mahmood Khan
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P. O. Box 577, Jhang Road, Faisalabad, Pakistan
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100
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Contreras-Cornejo HA, Macías-Rodríguez L, Alfaro-Cuevas R, López-Bucio J. Trichoderma spp. Improve growth of Arabidopsis seedlings under salt stress through enhanced root development, osmolite production, and Na⁺ elimination through root exudates. Mol Plant Microbe Interact 2014; 27:503-14. [PMID: 24502519 DOI: 10.1094/mpmi-09-13-0265-r] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Salt stress is an important constraint to world agriculture. Here, we report on the potential of Trichoderma virens and T. atroviride to induce tolerance to salt in Arabidopsis seedlings. We first characterized the effect of several salt concentrations on shoot biomass production and root architecture of Arabidopsis seedlings. We found that salt repressed plant growth and root development in a dose-dependent manner by blocking auxin signaling. Analysis of the wild type and eir1, aux1-7, arf7arf19, and tir1abf2abf19 auxin-related mutants revealed a key role for indole-3-acetic acid (IAA) signaling in mediating salt tolerance. We also found that T. virens (Tv29.8) and T. atroviride (IMI 206040) promoted plant growth in both normal and saline conditions, which was related to the induction of lateral roots and root hairs through auxin signaling. Arabidopsis seedlings grown under saline conditions inoculated with Trichoderma spp. showed increased levels of abscissic acid, L-proline, and ascorbic acid, and enhanced elimination of Na⁺ through root exudates. Our data show the critical role of auxin signaling and root architecture to salt tolerance in Arabidopsis and suggest that these fungi may enhance the plant IAA level as well as the antioxidant and osmoprotective status of plants under salt stress.
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