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König J, Guerreiro MA, Peršoh D, Begerow D, Krauss J. Knowing your neighbourhood-the effects of Epichloë endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity. PeerJ 2018; 6:e4660. [PMID: 29780665 PMCID: PMC5958879 DOI: 10.7717/peerj.4660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 04/02/2018] [Indexed: 12/21/2022] Open
Abstract
Epichloë endophytes associated with cool-season grass species can protect their hosts from herbivory and can suppress mycorrhizal colonization of the hosts' roots. However, little is known about whether or not Epichloë endophyte infection can also change the foliar fungal assemblages of the host. We tested 52 grassland study sites along a land-use intensity gradient in three study regions over two seasons (spring vs. summer) to determine whether Epichloë infection of the host grass Lolium perenne changes the fungal community structure in leaves. Foliar fungal communities were assessed by Next Generation Sequencing of the ITS rRNA gene region. Fungal community structure was strongly affected by study region and season in our study, while land-use intensity and infection with Epichloë endophytes had no significant effects. We conclude that effects on non-systemic endophytes resulting from land use practices and Epichloë infection reported in other studies were masked by local and seasonal variability in this study's grassland sites.
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Affiliation(s)
- Julia König
- Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg, Würzburg, Germany
| | | | - Derek Peršoh
- Department of Geobotany, Ruhr-Universität Bochum, Bochum, Germany
| | - Dominik Begerow
- Department of Geobotany, Ruhr-Universität Bochum, Bochum, Germany
| | - Jochen Krauss
- Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg, Würzburg, Germany
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Guerreiro MA, Brachmann A, Begerow D, Peršoh D. Transient leaf endophytes are the most active fungi in 1-year-old beech leaf litter. FUNGAL DIVERS 2018; 89:237-51. [DOI: 10.1007/s13225-017-0390-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Dziurka M, Janeczko A, Juhász C, Gullner G, Oklestková J, Novák O, Saja D, Skoczowski A, Tóbiás I, Barna B. Local and systemic hormonal responses in pepper leaves during compatible and incompatible pepper-tobamovirus interactions. Plant Physiol Biochem 2016; 109:355-364. [PMID: 27810675 DOI: 10.1016/j.plaphy.2016.10.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [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: 07/12/2016] [Revised: 10/13/2016] [Accepted: 10/13/2016] [Indexed: 05/04/2023]
Abstract
Phytohormone levels and the expression of genes encoding key enzymes participating in hormone biosynthetic pathways were investigated in pepper leaves inoculated with two different tobamoviruses. Obuda pepper virus (ObPV) inoculation led to the development of hypersensitive reaction (incompatible interaction), while Pepper mild mottle virus (PMMoV) inoculation resulted in a systemic, compatible interaction. ObPV-inoculation markedly increased not only the levels of salicylic acid (SA) (73-fold) and jasmonic acid (8-fold) but also those of abscisic acid, indole-3-acetic acid, indole-3-butyric acid, cis-zeatin, cis-zeatin-9-riboside and trans-zeatin-9-riboside in the inoculated pepper leaves 3 days post inoculation. PMMoV infection increased only the contents of gibberellic acid and SA. Hormone contents did not change significantly after ObPV or PMMoV infection in non-infected upper leaves 20 days post inoculation. Concentrations of some brassinosteroids (BRs) and progesterone increased both in ObPV- and PMMoV inoculated leaves. ObPV inoculation markedly induced the expression of three phenylalanine ammonia-lyase (PAL) and a 1-aminocyclopropane-1-carboxylate oxidase (ACO) genes, while that of an isochorismate synthase (ICS) gene was not modified. PMMoV inoculation did not alter the expression of PAL and ICS genes but induced the transcript abundance of ACO although later than ObPV. Pre-treatment of pepper leaves with exogenous 24-epi-brassinolide (24-epi-BR) prior to ObPV-inoculation strongly mitigated the visible symptoms caused by ObPV. In addition, 24-epi-BR pre-treatment markedly altered the level of several hormones in pepper leaves following ObPV-inoculation. These data indicate that ObPV- and PMMoV-inoculations lead to intricate but well harmonized hormonal responses that are largely determined by the incompatible or compatible nature of plant-virus interactions.
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Affiliation(s)
- Michał Dziurka
- Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland
| | - Anna Janeczko
- Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland
| | - Csilla Juhász
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary
| | - Gábor Gullner
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary
| | - Jana Oklestková
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacky University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ondrej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacky University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Diana Saja
- Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland
| | - Andrzej Skoczowski
- Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland
| | - István Tóbiás
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary
| | - Balázs Barna
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary.
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Jeandet P, Clément C, Courot E, Cordelier S. Modulation of phytoalexin biosynthesis in engineered plants for disease resistance. Int J Mol Sci 2013; 14:14136-70. [PMID: 23880860 PMCID: PMC3742236 DOI: 10.3390/ijms140714136] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [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: 04/25/2013] [Revised: 06/19/2013] [Accepted: 06/25/2013] [Indexed: 01/16/2023] Open
Abstract
Phytoalexins are antimicrobial substances of low molecular weight produced by plants in response to infection or stress, which form part of their active defense mechanisms. Starting in the 1950's, research on phytoalexins has begun with biochemistry and bio-organic chemistry, resulting in the determination of their structure, their biological activity as well as mechanisms of their synthesis and their catabolism by microorganisms. Elucidation of the biosynthesis of numerous phytoalexins has permitted the use of molecular biology tools for the exploration of the genes encoding enzymes of their synthesis pathways and their regulators. Genetic manipulation of phytoalexins has been investigated to increase the disease resistance of plants. The first example of a disease resistance resulting from foreign phytoalexin expression in a novel plant has concerned a phytoalexin from grapevine which was transferred to tobacco. Transformations were then operated to investigate the potential of other phytoalexin biosynthetic genes to confer resistance to pathogens. Unexpectedly, engineering phytoalexins for disease resistance in plants seem to have been limited to exploiting only a few phytoalexin biosynthetic genes, especially those encoding stilbenes and some isoflavonoids. Research has rather focused on indirect approaches which allow modulation of the accumulation of phytoalexin employing transcriptional regulators or components of upstream regulatory pathways. Genetic approaches using gain- or less-of functions in phytoalexin engineering together with modulation of phytoalexin accumulation through molecular engineering of plant hormones and defense-related marker and elicitor genes have been reviewed.
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Affiliation(s)
- Philippe Jeandet
- Laboratory of Stress, Defenses and Plant Reproduction, Research Unit “Vines and Wines of Champagne”, UPRES EA 4707, Faculty of Sciences, University of Reims, P.O. Box 1039, Reims 51687, France; E-Mails: (C.C.); (E.C.); (S.C.)
| | - Christophe Clément
- Laboratory of Stress, Defenses and Plant Reproduction, Research Unit “Vines and Wines of Champagne”, UPRES EA 4707, Faculty of Sciences, University of Reims, P.O. Box 1039, Reims 51687, France; E-Mails: (C.C.); (E.C.); (S.C.)
| | - Eric Courot
- Laboratory of Stress, Defenses and Plant Reproduction, Research Unit “Vines and Wines of Champagne”, UPRES EA 4707, Faculty of Sciences, University of Reims, P.O. Box 1039, Reims 51687, France; E-Mails: (C.C.); (E.C.); (S.C.)
| | - Sylvain Cordelier
- Laboratory of Stress, Defenses and Plant Reproduction, Research Unit “Vines and Wines of Champagne”, UPRES EA 4707, Faculty of Sciences, University of Reims, P.O. Box 1039, Reims 51687, France; E-Mails: (C.C.); (E.C.); (S.C.)
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Mialoundama AS, Heintz D, Debayle D, Rahier A, Camara B, Bouvier F. Abscisic acid negatively regulates elicitor-induced synthesis of capsidiol in wild tobacco. Plant Physiol 2009; 150:1556-66. [PMID: 19420326 PMCID: PMC2705044 DOI: 10.1104/pp.109.138420] [Citation(s) in RCA: 10] [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: 03/10/2009] [Accepted: 05/01/2009] [Indexed: 05/04/2023]
Abstract
In the Solanaceae, biotic and abiotic elicitors induce de novo synthesis of sesquiterpenoid stress metabolites known as phytoalexins. Because plant hormones play critical roles in the induction of defense-responsive genes, we have explored the effect of abscisic acid (ABA) on the synthesis of capsidiol, the major wild tobacco (Nicotiana plumbaginifolia) sesquiterpenoid phytoalexin, using wild-type plants versus nonallelic mutants Npaba2 and Npaba1 that are deficient in ABA synthesis. Npaba2 and Npaba1 mutants exhibited a 2-fold higher synthesis of capsidiol than wild-type plants when elicited with either cellulase or arachidonic acid or when infected by Botrytis cinerea. The same trend was observed for the expression of the capsidiol biosynthetic genes 5-epi-aristolochene synthase and 5-epi-aristolochene hydroxylase. Treatment of wild-type plants with fluridone, an inhibitor of the upstream ABA pathway, recapitulated the behavior of Npaba2 and Npaba1 mutants, while the application of exogenous ABA reversed the enhanced synthesis of capsidiol in Npaba2 and Npaba1 mutants. Concomitant with the production of capsidiol, we observed the induction of ABA 8'-hydroxylase in elicited plants. In wild-type plants, the induction of ABA 8'-hydroxylase coincided with a decrease in ABA content and with the accumulation of ABA catabolic products such as phaseic acid and dihydrophaseic acid, suggesting a negative regulation exerted by ABA on capsidiol synthesis. Collectively, our data indicate that ABA is not required per se for the induction of capsidiol synthesis but is essentially implicated in a stress-response checkpoint to fine-tune the amplification of capsidiol synthesis in challenged plants.
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Affiliation(s)
- Alexis Samba Mialoundama
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique and Université de Strasbourg, 67084 Strasbourg cedex, France
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Bachand GD, Castello JD. Seasonal pattern of tomato mosaic tobamovirus infection and concentration in red spruce seedlings. Appl Environ Microbiol 1998; 64:1436-41. [PMID: 16349546 PMCID: PMC106166 DOI: 10.1128/aem.64.4.1436-1441.1998] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/1997] [Accepted: 01/17/1998] [Indexed: 11/20/2022] Open
Abstract
Tomato mosaic tobamovirus (ToMV) infects red spruce (Picea rubens) and causes significant changes in its growth and physiology. The mechanism of infection and the pattern of virus concentration in seedling roots and needles were investigated. One-year-old red spruce seedlings were obtained from the nursery in April and June 1995 and August 1996 and tested for ToMV using enzyme-linked immunosorbent assay (ELISA). Virus-free seedlings were divided into three treatments: control, root inoculated, and needle inoculated. Two control, five root-inoculated, and five needle-inoculated seedlings were sampled destructively at biweekly intervals for 3 months and then tested for ToMV by ELISA. ToMV was transmitted to seedlings by root but not by needle inoculation. The virus was detected in 67 to 100% of roots but in less than 7% of needles of root-inoculated seedlings. The percent infection of root-inoculated seedlings differed significantly between the April and June and between the April and August inoculation periods. Virus concentration in infected seedling roots increased initially, peaked within 4 weeks postinoculation, and steadily declined thereafter. Significant differences in ToMV concentrations in roots also were detected among inoculation periods and sampling dates. Early spring may represent the optimal time for infection of seedlings, as well as for assaying roots for ToMV.
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Affiliation(s)
- G D Bachand
- Faculty of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, New York 13210-2788
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Abstract
The amounts of tobacco necrosis virus antigen from necrotic lesions in tobacco leaves were estimated by ELISA. Less than 10% variation among different plates was obtained for the same sample placed in 3 wells randomly selected among the 60 internal wells of the plates, including in each test a dilution series of purified virus. Huxley's simple allometry equations y = bxm (y, absorbance; x, virus concentration) were calculated for each plate and gave reproducible results within a large range of virus concentration. The amount of viral antigen recovered from the necrotic centres of lesions was always significantly lower than those from the living tissues of the halo surrounding the centre. The serological activity recovered from both necrotic and halo tissues was not increased upon various treatments with disaggregating agents. During the continuous growth of the lesions the amounts of viral antigen extracted from the necrotic centre linearly decreased with time, suggesting virus degradation, whereas the amounts of antigen extracted from the living halo tissues increased with time, indicating that mechanisms of restricting viral spread and multiplication were not operating.
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Whenham RJ, Fraser RS. Stimulation by abscisic acid of RNA synthesis in discs from healthy and tobacco mosaic virus-infected tobacco leaves. Planta 1980; 150:349-353. [PMID: 24306882 DOI: 10.1007/bf00390168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/1980] [Accepted: 07/22/1980] [Indexed: 06/02/2023]
Abstract
Uptake of abscisic acid from the culture medium by discs of healthy and tobacco mosaic virus-infected tobacco leaves was measured. Small (two to five-fold) increases in abscisic acid concentration in discs caused increases in rates of [(3)H]uridine and [(3)H]adenine incorporation into total nucleic acid, virus RNA and host ribosomal RNA. Net accumulation of virus RNA was also enhanced by abscisic acid. This evidence for stimulation of RNA synthesis is compared with previous reports showing inhibition of RNA synthesis in other tissues. It is suggested that the increase in endogenous abscisic acid caused by tobacco mosaic virus infection may be at least partly responsible for observed increases in rates of RNA synthesis after infection.
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Affiliation(s)
- R J Whenham
- Biochemistry Section, National Vegetable Research Station, Wellesbourne, CV35 9EF, Warwick, UK
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Pennazio S, D'Agostino G, Appiano A, Redolfi P. Ultrastructure and histochemistry of the resistant tissue surrounding lesions of tomato bushy stunt virus in Gomphrena globosa leaves. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0048-4059(78)90030-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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