1
|
Fortier CE, Musso AE, Evenden ML, Zaharia LI, Cooke JEK. Evidence that Ophiostomatoid Fungal Symbionts of Mountain Pine Beetle Do Not Play a Role in Overcoming Lodgepole Pine Defenses During Mass Attack. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:445-458. [PMID: 38240660 DOI: 10.1094/mpmi-06-23-0077-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a devastating forest insect pest that has killed millions of hectares of pines in western North America over the past two decades. Like other bark beetles, MPB vectors ophiostomatoid fungal species, some of which are pathogenic to host pine species. The phytopathogenicity of these fungal symbionts has sparked considerable debate regarding their role in facilitating MPB attack success. We tested the hypothesis that MPB ophiostomatoid fungal associates like Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield contribute to overwhelming host defenses during MPB mass attack. We compared responses of mature lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees growing in natural stands that were mass attacked by MPB with those inoculated with G. clavigera by examining host defense hormones, secondary metabolites, and gene expression profiles. The jasmonate and ethylene signatures of necrotrophic pathogen-triggered response were identified in G. clavigera-inoculated trees, but only the jasmonate signature of a herbivore-triggered response was measured in MPB-attacked trees. Several G. clavigera-induced changes in pine phenolic metabolite profiles and phenolic biosynthesis gene expression patterns were absent in MPB-attacked pines. These findings indicate that ophiostomatoid fungi like G. clavigera are not a major factor in overwhelming host defenses during MPB mass attack. Instead, fungal pathogenicity likely is more important in aiding MPB colonization and development within the host tree. Phenolics appear to play a larger role in the host response to G. clavigera than to MPB, although phenolics may also influence MPB feeding and behavior. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
Collapse
Affiliation(s)
- Colleen E Fortier
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Antonia E Musso
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Maya L Evenden
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - L Irina Zaharia
- National Research Council of Canada, Aquatic and Crop Resource Development Research Centre, Saskatoon, SK, S7N 0W9, Canada
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| |
Collapse
|
2
|
Zhang MX, Li J, Zhang XN, Li HH, Xu XF. Comparative transcriptome profiling of Termitomyces sp. between monocultures in vitro and link-stipe of fungus-combs in situ. Lett Appl Microbiol 2021; 74:429-443. [PMID: 34890484 DOI: 10.1111/lam.13628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/18/2021] [Accepted: 12/02/2021] [Indexed: 11/29/2022]
Abstract
The edible mushroom Termitomyces is an agaric-type basidiomycete fungus that has a symbiotic relationship with fungus-growing termites. An understanding of the detailed development mechanisms underlying the adaptive responses of Termitomyces sp. to their growing environment is lacking. Here, we compared the transcriptome sequences of different Termitomyces sp. samples and link-stipe grown on fungus combs in situ and monocultured in vitro. The assembled reads generated 8052 unigenes. The expression profiles were highly different for 2556 differentially expressed genes (DEGs) of the treated samples, where the expression of 1312 and 1244 DEGs was upregulated in the Mycelium and link-stipe groups respectively. Functional classification of the DEGs based on both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed an expected shift in fungal gene expression, where stress response genes whose expression was upregulated in link-stipe may adaptively be involved in cell wall hydrolysis and fusion, pathogenesis, oxidation-reduction, transporter efflux, transposon efflux and self/non-self-recognition. Urease has implications in the expression of genes involved in the nitrogen metabolism pathway, and its expression could be controlled by low-level nitrogen fixation of fungus combs. In addition, the expression patterns of eleven select genes on the basis of qRT-PCR were consistent with their changes in transcript abundance, as revealed by RNA sequencing. Taken together, these findings may be useful for enriching the knowledge concerning the Termitomyces adaptive response to in situ fungus combs compared with the response of monocultures in vitro.
Collapse
Affiliation(s)
- M-X Zhang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - J Li
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - X-N Zhang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - H-H Li
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - X-F Xu
- College of Food Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
3
|
Capador-Barreto HD, Bernhardsson C, Milesi P, Vos I, Lundén K, Wu HX, Karlsson B, Ingvarsson PK, Stenlid J, Elfstrand M. Killing two enemies with one stone? Genomics of resistance to two sympatric pathogens in Norway spruce. Mol Ecol 2021; 30:4433-4447. [PMID: 34218489 DOI: 10.1111/mec.16058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 12/31/2022]
Abstract
Trees must cope with the attack of multiple pathogens, often simultaneously during their long lifespan. Ironically, the genetic and molecular mechanisms controlling this process are poorly understood. The objective of this study was to compare the genetic component of resistance in Norway spruce to Heterobasidion annosum s.s. and its sympatric congener Heterobasidion parviporum. Heterobasidion root- and stem-rot is a major disease of Norway spruce caused by members of the Heterobasidion annosum species complex. Resistance to both pathogens was measured using artificial inoculations in half-sib families of Norway spruce trees originating from central to northern Europe. The genetic component of resistance was analysed using 63,760 genome-wide exome-capture sequenced SNPs and multitrait genome-wide associations. No correlation was found for resistance to the two pathogens; however, associations were found between genomic variants and resistance traits with synergic or antagonist pleiotropic effects to both pathogens. Additionally, a latitudinal cline in resistance in the bark to H. annosum s.s. was found; trees from southern latitudes, with a later bud-set and thicker stem diameter, allowed longer lesions, but this was not the case for H. parviporum. In summary, this study detects genomic variants with pleiotropic effects which explain multiple disease resistance from a genic level and could be useful for selection of resistant trees to both pathogens. Furthermore, it highlights the need for additional research to understand the evolution of resistance traits to multiple pathogens in trees.
Collapse
Affiliation(s)
- Hernán D Capador-Barreto
- Uppsala Biocentre, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Carolina Bernhardsson
- Uppsala Biocentre, Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Pascal Milesi
- Department of Ecology and Genetics, Evolutionary Biology Centre, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ingrid Vos
- Forestry Research Institute of Sweden (Skogforsk), Ekebo, Sweden
| | - Karl Lundén
- Uppsala Biocentre, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Harry X Wu
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Bo Karlsson
- Forestry Research Institute of Sweden (Skogforsk), Ekebo, Sweden
| | - Pär K Ingvarsson
- Uppsala Biocentre, Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jan Stenlid
- Uppsala Biocentre, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Malin Elfstrand
- Uppsala Biocentre, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| |
Collapse
|
4
|
Liu M, Jaber E, Zeng Z, Kovalchuk A, Asiegbu FO. Physiochemical and molecular features of the necrotic lesion in the Heterobasidion-Norway spruce pathosystem. TREE PHYSIOLOGY 2021; 41:791-800. [PMID: 33105481 DOI: 10.1093/treephys/tpaa141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/03/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
In the forest of Northern Hemisphere, the fungi Heterobasidion annosum (Fr.) Bref. s.l. causes severe root and stem rot diseases, dramatically reducing the wood quality of conifer trees. The hallmark of the host response during the infection process is the formation of necrotic lesions and reaction zones. To characterize physiochemical and molecular features of the necrotic lesion, we conducted artificial inoculations on Norway spruce plants at different developmental stages: seedlings, young and mature trees. The results were further compared against data available on the formation of reaction zones. Strong necrosis browning or enlarged necrotic lesions were observed in infected tissues. This was accompanied by elevated pH. However, the increased pH, around 6.0 in necrotic lesions, was not as high as that documented in reaction zones, above 7.0 as marked by the intensity of the blue colour in response to 2,6-dichlorophenol indophenol dye. Peroxidase activity increased in infected plants and RNA-seq analysis of necrotic lesions showed marked upregulation of defence-related genes. Our findings highlight similarities and differences between the reaction zone and necrotic lesion formation in response of conifer trees to biotic stress.
Collapse
Affiliation(s)
- Mengxia Liu
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, PO Box 27, FIN-00014, Helsinki, Finland
| | - Emad Jaber
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, PO Box 27, FIN-00014, Helsinki, Finland
| | - Zhen Zeng
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, PO Box 27, FIN-00014, Helsinki, Finland
| | - Andriy Kovalchuk
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, PO Box 27, FIN-00014, Helsinki, Finland
| | - Fred O Asiegbu
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, PO Box 27, FIN-00014, Helsinki, Finland
| |
Collapse
|
5
|
Hettiarachchige IK, Vander Jagt CJ, Mann RC, Sawbridge TI, Spangenberg GC, Guthridge KM. Global Changes in Asexual Epichloë Transcriptomes during the Early Stages, from Seed to Seedling, of Symbiotum Establishment. Microorganisms 2021; 9:microorganisms9050991. [PMID: 34064362 PMCID: PMC8147782 DOI: 10.3390/microorganisms9050991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/30/2021] [Accepted: 04/30/2021] [Indexed: 11/16/2022] Open
Abstract
Asexual Epichloë fungi are strictly seed-transmitted endophytic symbionts of cool-season grasses and spend their entire life cycle within the host plant. Endophyte infection can confer protective benefits to its host through the production of bioprotective compounds. Inversely, plants provide nourishment and shelter to the resident endophyte in return. Current understanding of the changes in global gene expression of asexual Epichloë endophytes during the early stages of host-endophyte symbiotum is limited. A time-course study using a deep RNA-sequencing approach was performed at six stages of germination, using seeds infected with one of three endophyte strains belonging to different representative taxa. Analysis of the most abundantly expressed endophyte genes identified that most were predicted to have a role in stress and defence responses. The number of differentially expressed genes observed at early time points was greater than those detected at later time points, suggesting an active transcriptional reprogramming of endophytes at the onset of seed germination. Gene ontology enrichment analysis revealed dynamic changes in global gene expression consistent with the developmental processes of symbiotic relationships. Expression of pathway genes for biosynthesis of key secondary metabolites was studied comprehensively and fuzzy clustering identified some unique expression patterns. Furthermore, comparisons of the transcriptomes from three endophyte strains in planta identified genes unique to each strain, including genes predicted to be associated with secondary metabolism. Findings from this study highlight the importance of better understanding the unique properties of individual endophyte strains and will serve as an excellent resource for future studies of host-endophyte interactions.
Collapse
Affiliation(s)
- Inoka K. Hettiarachchige
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Christy J. Vander Jagt
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Ross C. Mann
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
| | - Timothy I. Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3086, Australia
| | - German C. Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3086, Australia
| | - Kathryn M. Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (C.J.V.J.); (R.C.M.); (T.I.S.); (G.C.S.)
- Correspondence:
| |
Collapse
|
6
|
Šķipars V, Ruņģis D. Transcript Dynamics in Wounded and Inoculated Scots Pine. Int J Mol Sci 2021; 22:ijms22041505. [PMID: 33546141 PMCID: PMC7913219 DOI: 10.3390/ijms22041505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 11/16/2022] Open
Abstract
Comparative transcriptome analysis provides a useful tool for the exploration of plant-pathogen interaction by allowing in-depth comparison of gene expression between unaffected, inoculated and wounded organisms. Here we present the results of comparative transcriptome analysis in genetically identical one-year-old Scots pine ramets after wounding and inoculation with Heterobasidion annosum. We identified 230 genes that were more than 2-fold upregulated in inoculated samples (compared to controls) and 116 downregulated genes. Comparison of inoculated samp les with wounded samples identified 32 differentially expressed genes (30 were upregulated after inoculation). Several of the genes upregulated after inoculation are involved in protection from oxidative stress, while genes involved in photosynthesis, water transport and drought stress tolerance were downregulated. An NRT3 family protein was the most upregulated transcript in response to both inoculation and wounding, while a U-box domain-containing protein gene was the most upregulated gene comparing inoculation to wounding. The observed transcriptome dynamics suggest involvement of auxin, ethylene, jasmonate, gibberellin and reactive oxygen species pathways and cell wall modification regulation in response to H. annosum infection. The results are compared to methyl jasmonate induced transcriptome dynamics.
Collapse
|
7
|
Trujillo-Moya C, Ganthaler A, Stöggl W, Kranner I, Schüler S, Ertl R, Schlosser S, George JP, Mayr S. RNA-Seq and secondary metabolite analyses reveal a putative defence-transcriptome in Norway spruce (Picea abies) against needle bladder rust (Chrysomyxa rhododendri) infection. BMC Genomics 2020; 21:336. [PMID: 32357832 PMCID: PMC7195740 DOI: 10.1186/s12864-020-6587-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/18/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Norway spruce trees in subalpine forests frequently face infections by the needle rust fungus Chrysomyxa rhododendri, which causes significant growth decline and increased mortality of young trees. Yet, it is unknown whether trees actively respond to fungal attack by activating molecular defence responses and/or respective gene expression. RESULTS Here, we report results from an infection experiment, in which the transcriptomes (via RNA-Seq analysis) and phenolic profiles (via UHPLC-MS) of control and infected trees were compared over a period of 39 days. Gene expression between infected and uninfected ramets significantly differed after 21 days of infection and revealed already known, but also novel candidate genes involved in spruce molecular defence against pathogens. CONCLUSIONS Combined RNA-Seq and biochemical data suggest that Norway spruce response to infection by C. rhododendri is restricted locally and primarily activated between 9 and 21 days after infestation, involving a potential isolation of the fungus by a hypersensitive response (HR) associated with an activation of phenolic pathways. Identified key regulatory genes represent a solid basis for further specific analyses in spruce varieties with varying susceptibility, to better characterise resistant clones and to elucidate the resistance mechanism.
Collapse
Affiliation(s)
- Carlos Trujillo-Moya
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)-Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Wolfgang Stöggl
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Silvio Schüler
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)- Department of Forest Growth & Silviculture, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Reinhard Ertl
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Sarah Schlosser
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Jan-Peter George
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)-Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| |
Collapse
|
8
|
Hu Y, Elfstrand M, Stenlid J, Durling MB, Olson Å. The conifer root rot pathogens Heterobasidion irregulare and Heterobasidion occidentale employ different strategies to infect Norway spruce. Sci Rep 2020; 10:5884. [PMID: 32246017 PMCID: PMC7125170 DOI: 10.1038/s41598-020-62521-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 03/10/2020] [Indexed: 11/16/2022] Open
Abstract
Heterobasidion irregulare and H. occidentale are two closely related conifer root rot pathogens in the H. annosum sensu lato (s.l.) species complex. The two species H. irregulare and H. occidentale have different host preference with pine and non-pine tree species favored, respectively. The comparison of transcriptomes of H. irregulare and H. occidentale growing in Norway spruce bark, a susceptible host non-native to North America, showed large differences in gene expression. Heterobasidion irregulare induced more genes involved in detoxification of host compounds and in production of secondary metabolites, while the transcriptome induced in H. occidentale was more oriented towards carbohydrate degradation. Along with their separated evolutionary history, the difference might be driven by their host preferences as indicated by the differentially expressed genes enriched in particular Gene Ontology terms.
Collapse
Affiliation(s)
- Yang Hu
- Zhejiang Academy of Forestry, Liuhe Road, 310023, Hangzhou, China.,Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 05, Uppsala, Sweden
| | - Malin Elfstrand
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 05, Uppsala, Sweden
| | - Jan Stenlid
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 05, Uppsala, Sweden
| | - Mikael Brandström Durling
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 05, Uppsala, Sweden
| | - Åke Olson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 05, Uppsala, Sweden.
| |
Collapse
|
9
|
Wang Q, Guo M, Xu R, Zhang J, Bian Y, Xiao Y. Transcriptional Changes on Blight Fruiting Body of Flammulina velutipes Caused by Two New Bacterial Pathogens. Front Microbiol 2020; 10:2845. [PMID: 31921028 PMCID: PMC6917577 DOI: 10.3389/fmicb.2019.02845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/22/2019] [Indexed: 11/13/2022] Open
Abstract
A blight disease of Flammulina velutipes was identified with symptoms of growth cessation of young fruiting bodies, short stipe, and brown spots on the pileus. The pathogenic bacteria were identified as Arthrobacter arilaitensis and Pseudomonas yamanorum by Koch's postulate, gram staining, morphological and 16S ribosomal RNA gene sequence analyses. Either of the pathogenic bacteria or both of them can cause the same symptoms. Transcriptome changes in blighted F. velutipes were investigated between diseased and normal samples. Compared to the control group, 1,099 differentially expressed genes (DEGs) were overlapping in the bacteria-infected groups. The DEGs were significantly enriched in pathways such as xenobiotic metabolism by cytochrome P450 and tyrosine metabolism. Based on weighted correlation network analysis (WGCNA), the module most correlated to the pathogen-treated F. velutipes samples and candidate hub genes in the co-regulatory network were identified. Furthermore, a potential diseased mechanism involved in cell wall non-extension, phenolic substrate oxidation, and stress defense response was proposed based on the up-regulation of differentially expressed genes encoding chitin deacetylase, tyrosinase, cytochrome P450, MFS transporter, and clavaminate synthase-like protein. This study provides insights into the underlying reactions of young fruiting body of F. velutipes suffering from blight disease and facilitates the understanding of the pathogenic procedure of bacteriosis in edible mushrooms.
Collapse
Affiliation(s)
- Qing Wang
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| | - Mengpei Guo
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| | - Ruiping Xu
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| | - Jingcheng Zhang
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| | - Yinbing Bian
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| | - Yang Xiao
- College of Plant Science and Technology, Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
10
|
Wagner K, Krause K, Gallegos-Monterrosa R, Sammer D, Kovács ÁT, Kothe E. The Ectomycorrhizospheric Habitat of Norway Spruce and Tricholoma vaccinum: Promotion of Plant Growth and Fitness by a Rich Microorganismic Community. Front Microbiol 2019; 10:307. [PMID: 30842767 PMCID: PMC6391851 DOI: 10.3389/fmicb.2019.00307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 02/05/2019] [Indexed: 11/23/2022] Open
Abstract
The contribution of the mycorrhizospheric microbes in a stand of ectomycorrhizal Norway spruce (Picea abies) featuring mycorrhiza with the basidiomycete Tricholoma vaccinum was addressed by microbiome analysis and in vitro reconstruction of microbial as well as plant-microbe interactions. The protective role of the mycorrhizal fungus with respect to pathogen attack could be validated against Botrytis cinerea and Heterobasidion annosum in co-cultures revealing reduced pathogen growth, higher survival rate of the spruce trees and reduced symptoms on needles upon symbiosis with T. vaccinum. The community structure was shown to yield a high diversity in ECM forming basidiomycetes of Thelephorales and Agaricales associated with a rich bacterial diversity dominated by Rhizobiales with the most abundant Nitrobacter winogradski (3.9%). Isolated bacteria were then used to address plant growth promoting abilities, which included production of the phytohormone indole-3-acetic acid (performed by 74% of the bacterial isolates), siderophores (22%), and phosphate mobilization (23%). Among the isolates, mycorrhiza helper bacteria (MHB) were identified, with Bacillus cereus MRZ-1 inducing hyperbranching in T. vaccinum, supporting tree germination, shoot elongation, and root formation as well as higher mycorrhization rates. Thus, a huge pool of potential MHB and fungal community with widely distributed auxin-production potential extended the ability of T. vaccinum to form ectomycorrhiza. The forest community profited from the mycorrhizal fungus T. vaccinum, with spruce survival enhanced by 33% in microcosms using soil from the native habitat. A higher fungal abundance and diversity in cases where the tree had died during the experiment, showing that decomposition of plant litter from a dead tree supported a different community. T. vaccinum thus actively structured the community of microorganisms in its habitat.
Collapse
Affiliation(s)
- Katharina Wagner
- Microbial Communication, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Katrin Krause
- Microbial Communication, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Ramses Gallegos-Monterrosa
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Dominik Sammer
- Microbial Communication, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Ákos T Kovács
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Erika Kothe
- Microbial Communication, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
11
|
Kovalchuk A, Zeng Z, Ghimire RP, Kivimäenpää M, Raffaello T, Liu M, Mukrimin M, Kasanen R, Sun H, Julkunen-Tiitto R, Holopainen JK, Asiegbu FO. Dual RNA-seq analysis provides new insights into interactions between Norway spruce and necrotrophic pathogen Heterobasidion annosum s.l. BMC PLANT BIOLOGY 2019; 19:2. [PMID: 30606115 PMCID: PMC6318961 DOI: 10.1186/s12870-018-1602-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/12/2018] [Indexed: 05/10/2023]
Abstract
BACKGROUND Root and butt rot of conifer trees caused by fungi belonging to the Heterobasidion annosum species complex is one of the most economically important fungal diseases in commercial conifer plantations throughout the Northern hemisphere. We investigated the interactions between Heterobasidion fungi and their host by conducting dual RNA-seq and chemical analysis on Norway spruce trees naturally infected by Heterobasidion spp. We analyzed host and pathogen transcriptome and phenolic and terpenoid contents of the spruce trees. RESULTS Presented results emphasize the role of the phenylpropanoid and flavonoid pathways in the chemical defense of Norway spruce trees. Accumulation of lignans was observed in trees displaying symptoms of wood decay. A number of candidate genes with a predicted role in the higher level regulation of spruce defense responses were identified. Our data indicate a possible role of abscisic acid (ABA) signaling in the spruce defense against Heterobasidion infection. Fungal transcripts corresponding to genes encoding carbohydrate- and lignin-degrading enzymes, secondary metabolism genes and effector-like genes were expressed during the host colonization. CONCLUSIONS Our results provide additional insight into defense strategies employed by Norway spruce trees against Heterobasidion infection. The potential applications of the identified candidate genes as markers for higher resistance against root and butt rot deserve further evaluation.
Collapse
Affiliation(s)
- Andriy Kovalchuk
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| | - Zhen Zeng
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| | - Rajendra P. Ghimire
- Department of Environmental and Biological Sciences, Kuopio Campus, University of Eastern Finland (UEF), P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Minna Kivimäenpää
- Department of Environmental and Biological Sciences, Kuopio Campus, University of Eastern Finland (UEF), P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Tommaso Raffaello
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| | - Mengxia Liu
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| | - Mukrimin Mukrimin
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
- Department of Forestry, Universitas Hasanuddin, Jln. Perintis Kemerdekaan Km. 10, Makassar, 90245 Indonesia
| | - Risto Kasanen
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| | - Hui Sun
- Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Riitta Julkunen-Tiitto
- Department of Environmental and Biological Sciences, Joensuu Campus, University of Eastern Finland (UEF), P.O. Box 111, FIN-80101 Joensuu, Finland
| | - Jarmo K. Holopainen
- Department of Environmental and Biological Sciences, Kuopio Campus, University of Eastern Finland (UEF), P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Fred O. Asiegbu
- Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland
| |
Collapse
|
12
|
Pepori AL, Michelozzi M, Santini A, Cencetti G, Bonello P, Gonthier P, Sebastiani F, Luchi N. Comparative transcriptional and metabolic responses of Pinus pinea to a native and a non-native Heterobasidion species. TREE PHYSIOLOGY 2019; 39:31-44. [PMID: 30137615 DOI: 10.1093/treephys/tpy086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/31/2018] [Indexed: 05/28/2023]
Abstract
Heterobasidion irregulare is a causal agent of root and butt-rot disease in conifers, and is native to North America. In 1944 it was introduced in central Italy in a Pinus pinea stand, where it shares the same niche with the native species Heterobasidion annosum. The introduction of a non-native pathogen may have significant negative effects on a naïve host tree and the ecosystem in which it resides, requiring a better understanding of the system. We compared the spatio-temporal phenotypic, transcriptional and metabolic host responses to inoculation with the two Heterobasidion species in a large experiment with P. pinea seedlings. Differences in length of lesions at the inoculation site (IS), expression of host genes involved in lignin pathway and in cell rescue and defence, and analysis of terpenes at both IS and 12 cm above the IS (distal site, DS), were assessed at 3, 14 and 35 days post inoculation (dpi). Results clearly showed that both species elicit similar physiological and biochemical responses in P. pinea seedlings. The analysis of host transcripts and total terpenes showed differences between inoculation sites and between pathogen and mock inoculated plants. Both pathogen and mock inoculations induced antimicrobial peptide and phenylalanine ammonia-lyase overexpression at IS beginning at 3 dpi; while at DS all the analysed genes, except for peroxidase, were overexpressed at 14 dpi. A significantly higher accumulation of terpenoids was observed at 14 dpi at IS, and at 35 dpi at DS. The terpene blend at IS showed significant variation among treatments and sampling times, while no significant differences were ever observed in DS tissues. Based on our results, H. irregulare does not seem to have competitive advantages over the native species H. annosum in terms of pathogenicity towards P. pinea trees; this may explain why the non-native species has not widely spread over the 73 years since its putative year of introduction into central Italy.
Collapse
Affiliation(s)
- Alessia Lucia Pepori
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| | - Marco Michelozzi
- Institute of Biosciences and Bioresources, National Research Council (IBBR-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| | - Alberto Santini
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| | - Gabriele Cencetti
- Institute of Biosciences and Bioresources, National Research Council (IBBR-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, 201 Kottman Hall, 2021 Coffey Rd, Columbus, OH, USA
| | - Paolo Gonthier
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Paolo Braccini 2, Grugliasco, TO, Italy
| | - Federico Sebastiani
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| | - Nicola Luchi
- Institute for Sustainable Plant Protection, National Research Council (IPSP-CNR), Via Madonna del Piano, Sesto Fiorentino (FI), Italy
| |
Collapse
|
13
|
Liu J, Shamoun SF, Leal I, Kowbel R, Sumampong G, Zamany A. Characterization of Heterobasidion occidentale transcriptomes reveals candidate genes and DNA polymorphisms for virulence variations. Microb Biotechnol 2018; 11:537-550. [PMID: 29611344 PMCID: PMC5954486 DOI: 10.1111/1751-7915.13259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/09/2018] [Accepted: 02/13/2018] [Indexed: 11/29/2022] Open
Abstract
Characterization of genes involved in differentiation of pathogen species and isolates with variations of virulence traits provides valuable information to control tree diseases for meeting the challenges of sustainable forest health and phytosanitary trade issues. Lack of genetic knowledge and genomic resources hinders novel gene discovery, molecular mechanism studies and development of diagnostic tools in the management of forest pathogens. Here, we report on transcriptome profiling of Heterobasidion occidentale isolates with contrasting virulence levels. Comparative transcriptomic analysis identified orthologous groups exclusive to H. occidentale and its isolates, revealing biological processes involved in the differentiation of isolates. Further bioinformatics analyses identified an H. occidentale secretome, CYPome and other candidate effectors, from which genes with species- and isolate-specific expression were characterized. A large proportion of differentially expressed genes were revealed to have putative activities as cell wall modification enzymes and transcription factors, suggesting their potential roles in virulence and fungal pathogenesis. Next, large numbers of simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) were detected, including more than 14 000 interisolate non-synonymous SNPs. These polymorphic loci and species/isolate-specific genes may contribute to virulence variations and provide ideal DNA markers for development of diagnostic tools and investigation of genetic diversity.
Collapse
Affiliation(s)
- Jun‐Jun Liu
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| | - Simon Francis Shamoun
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| | - Isabel Leal
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| | - Robert Kowbel
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| | - Grace Sumampong
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| | - Arezoo Zamany
- Natural Resources CanadaCanadian Forest ServicePacific Forestry Centre506 West Burnside RoadVictoriaBCV8Z 1M5Canada
| |
Collapse
|
14
|
Giordano L, Sillo F, Garbelotto M, Gonthier P. Mitonuclear interactions may contribute to fitness of fungal hybrids. Sci Rep 2018; 8:1706. [PMID: 29374209 PMCID: PMC5786003 DOI: 10.1038/s41598-018-19922-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 01/05/2018] [Indexed: 12/15/2022] Open
Abstract
Hybridization between species is being recognized as a major force in the rapid adaptive evolution of fungal plant pathogens. The first stages of interspecific hybridization necessarily involve nuclear-mitochondrial chimeras. In their 2001 publication, Olson and Stenlid reported that mitochondria control the virulence of first generation hybrids between the North American fungal pathogen Heterobasidion irregulare and its congeneric H. occidentale. By assessing saprobic ability and gene expression of H. irregulare × H. annosum sensu stricto hybrids and of their parental genotypes, we demonstrate that mitochondria also influence saprobic growth of hybrids. Moreover, gene expression data suggest that fungal fitness is modulated by an intimate interplay between nuclear genes and mitochondrial type, and is dependent on the specific mitonuclear combination.
Collapse
Affiliation(s)
- Luana Giordano
- University of Torino, Department of Agricultural, Forest and Food Sciences (DISAFA), Largo Paolo Braccini 2, I-10095, Grugliasco (TO), Italy.,Centre of Competence for the Innovation in the Agro-Environmental Field (AGROINNOVA), University of Torino, Largo Paolo Braccini 2, I-10095, Grugliasco (TO), Italy
| | - Fabiano Sillo
- University of Torino, Department of Agricultural, Forest and Food Sciences (DISAFA), Largo Paolo Braccini 2, I-10095, Grugliasco (TO), Italy.
| | - Matteo Garbelotto
- University of California, Berkeley, Department of Environmental Science, Policy and Management, Forest Pathology and Mycology Laboratory, 54 Mulford Hall, 94720, Berkeley, California, USA
| | - Paolo Gonthier
- University of Torino, Department of Agricultural, Forest and Food Sciences (DISAFA), Largo Paolo Braccini 2, I-10095, Grugliasco (TO), Italy
| |
Collapse
|
15
|
Choi J, Lee GW, Kim KT, Jeon J, Détry N, Kuo HC, Sun H, Asiegbu FO, Lee YH. Comparative analysis of genome sequences of the conifer tree pathogen, Heterobasidion annosum s.s. GENOMICS DATA 2017; 14:106-113. [PMID: 29085779 PMCID: PMC5654758 DOI: 10.1016/j.gdata.2017.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/21/2017] [Accepted: 10/15/2017] [Indexed: 01/09/2023]
Abstract
The causal agent of root and butt rot of conifer trees, Heterobasidion annosum, is widespread in boreal forests and economically responsible for annual loss of approximately 50 million euros to forest industries in Finland alone and much more at European level. In order to further understand the pathobiology of this fungus at the genome level, a Finnish isolate of H. annosum sensu stricto (isolate 03012) was sequenced and analyzed with the genome sequences of 23 white-rot and 13 brown-rot fungi. The draft genome assembly of H. annosum has a size of 31.01 Mb, containing 11,453 predicted genes. Whole genome alignment showed that 84.38% of H. annosum genome sequences were aligned with those of previously sequenced H. irregulare TC 32-1 counterparts. The result is further supported by the protein sequence clustering analysis which revealed that the two genomes share 6719 out of 8647 clusters. When sequencing reads of H. annosum were aligned against the genome sequences of H. irregulare, six single nucleotide polymorphisms were found in every 1 kb, on average. In addition, 98.68% of SNPs were found to be homo-variants, suggesting that the two species have long evolved from different niches. Gene family analysis revealed that most of the white-rot fungi investigated had more gene families involved in lignin degradation or modification, including laccases and peroxidase. Comparative analysis of the two Heterobasidion spp. as well as white-/brown-rot fungi would provide new insights for understanding the pathobiology of the conifer tree pathogen.
Collapse
Affiliation(s)
- Jaeyoung Choi
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Gir-Won Lee
- National Instrumentation Center for Environmental Management, Seoul National University, Seoul 08826, Republic of Korea
| | - Ki-Tae Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Jongbum Jeon
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Nicolas Détry
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Hsiao-Che Kuo
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Hui Sun
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Fred O Asiegbu
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Yong-Hwan Lee
- Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland.,Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea.,Center for Fungal Genetic Resources, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
16
|
Linnakoski R, Forbes KM, Wingfield MJ, Pulkkinen P, Asiegbu FO. Testing Projected Climate Change Conditions on the Endoconidiophora polonica / Norway spruce Pathosystem Shows Fungal Strain Specific Effects. FRONTIERS IN PLANT SCIENCE 2017; 8:883. [PMID: 28603538 PMCID: PMC5445173 DOI: 10.3389/fpls.2017.00883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/11/2017] [Indexed: 05/04/2023]
Abstract
Climate changes, exemplified by increased temperatures and CO2 concentration, pose a global threat to forest health. Of particular concern are pests and pathogens, with a warming climate altering their distributions and evolutionary capacity, while impairing the ability of some plants to respond to infections. Progress in understanding and mitigating such effects is currently hindered by a lack of empirical research. Norway spruce (Picea abies) is one of the most economically important tree species in northern Europe, and is considered highly vulnerable to changes in climate. It is commonly infected by the fungus Endoconidiophora polonica, and we hypothesized that damage caused to trees will increase under future climate change predictions. To test this hypothesis an in vivo greenhouse experiment was conducted to evaluate the effects of a changed growing environment on E. polonica infected Norway spruce seedlings, comparing ambient conditions to predicted temperatures and CO2 levels in Finland for the years 2030 and 2100. In total, 450 seedlings were randomized amongst the three treatments, with 25 seedlings from each allocated to inoculation with one of five different fungal strains or mock-inoculation. Seedlings were monitored throughout the thermal growing season for mortality, and lesion length and depth indices were measured at the experiment conclusion. Disease severity (mortality and lesions) was consistently greater in fungal-inoculated than mock-inoculated seedlings. However, substantial differences were observed among fungal strains in response to climate scenarios. For example, although overall seedling mortality was highest under the most distant (and severe) climate change expectations, of the two fungal strains with the highest mortality counts (referred to as F4 and F5), one produced greater mortality under the 2030 and 2100 scenarios than ambient conditions, whereas climate scenario had no effect on the other. This study contributes to a limited body of empirical research on the effects of projected climate changes on forestry pathosystems, and is the first to investigate interactions between Norway spruce and E. polonica. The results indicate the potential for future climate changes to alter the impact of forest pathogens with implications for productivity, while highlighting the need for a strain-specific level of understanding of the disease agents.
Collapse
Affiliation(s)
- Riikka Linnakoski
- Department of Forest Sciences, University of HelsinkiHelsinki, Finland
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | | | - Michael J. Wingfield
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | | | - Fred O. Asiegbu
- Department of Forest Sciences, University of HelsinkiHelsinki, Finland
| |
Collapse
|
17
|
Dalman K, Wind JJ, Nemesio-Gorriz M, Hammerbacher A, Lundén K, Ezcurra I, Elfstrand M. Overexpression of PaNAC03, a stress induced NAC gene family transcription factor in Norway spruce leads to reduced flavonol biosynthesis and aberrant embryo development. BMC PLANT BIOLOGY 2017; 17:6. [PMID: 28061815 PMCID: PMC5219727 DOI: 10.1186/s12870-016-0952-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/15/2016] [Indexed: 05/20/2023]
Abstract
BACKGROUND The NAC family of transcription factors is one of the largest gene families of transcription factors in plants and the conifer NAC gene family is at least as large, or possibly larger, as in Arabidopsis. These transcription factors control both developmental and stress induced processes in plants. Yet, conifer NACs controlling stress induced processes has received relatively little attention. This study investigates NAC family transcription factors involved in the responses to the pathogen Heterobasidion annosum (Fr.) Bref. sensu lato. RESULTS The phylogeny and domain structure in the NAC proteins can be used to organize functional specificities, several well characterized stress-related NAC proteins are found in III-3 in Arabidopsis (Jensen et al. Biochem J 426:183-196, 2010). The Norway spruce genome contain seven genes with similarity to subgroup III-3 NACs. Based on the expression pattern PaNAC03 was selected for detailed analyses. Norway spruce lines overexpressing PaNAC03 exhibited aberrant embryo development in response to maturation initiation and 482 misregulated genes were identified in proliferating cultures. Three key genes in the flavonoid biosynthesis pathway: a CHS, a F3'H and PaLAR3 were consistently down regulated in the overexpression lines. In accordance, the overexpression lines showed reduced levels of specific flavonoids, suggesting that PaNAC03 act as a repressor of this pathway, possibly by directly interacting with the promoter of the repressed genes. However, transactivation studies of PaNAC03 and PaLAR3 in Nicotiana benthamiana showed that PaNAC03 activated PaLAR3A, suggesting that PaNAC03 does not act as an independent negative regulator of flavan-3-ol production through direct interaction with the target flavonoid biosynthetic genes. CONCLUSIONS PaNAC03 and its orthologs form a sister group to well characterized stress-related angiosperm NAC genes and at least PaNAC03 is responsive to biotic stress and appear to act in the control of defence associated secondary metabolite production.
Collapse
Affiliation(s)
- Kerstin Dalman
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Chemistry and Biotechnology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Julia Johanna Wind
- KTH Biotechnology, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Miguel Nemesio-Gorriz
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Almuth Hammerbacher
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Karl Lundén
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ines Ezcurra
- KTH Biotechnology, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Malin Elfstrand
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Forest Mycology and Plant Pathology, SLU, PO. Box 7026, Uppsala, 75007 Sweden
| |
Collapse
|
18
|
Nemesio-Gorriz M, Blair PB, Dalman K, Hammerbacher A, Arnerup J, Stenlid J, Mukhtar SM, Elfstrand M. Identification of Norway Spruce MYB-bHLH-WDR Transcription Factor Complex Members Linked to Regulation of the Flavonoid Pathway. FRONTIERS IN PLANT SCIENCE 2017; 8:305. [PMID: 28337212 PMCID: PMC5343035 DOI: 10.3389/fpls.2017.00305] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/20/2017] [Indexed: 05/16/2023]
Abstract
Transcription factors (TFs) forming MYB-bHLH-WDR complexes are known to regulate the biosynthesis of specialized metabolites in angiosperms through an intricate network. These specialized metabolites participate in a wide range of biological processes including plant growth, development, reproduction as well as in plant immunity. Studying the regulation of their biosynthesis is thus essential. While MYB (TFs) have been previously shown to control specialized metabolism (SM) in gymnosperms, the identity of their partners, in particular bHLH or WDR members, has not yet been revealed. To gain knowledge about MYB-bHLH-WDR transcription factor complexes in gymnosperms and their regulation of SW, we identified two bHLH homologs of AtTT8, six homologs of the MYB transcription factor AtTT2 and one WDR ortholog of AtTTG1 in Norway spruce. We investigated the expression levels of these genes in diverse tissues and upon treatments with various stimuli including methyl-salicylate, methyl-jasmonate, wounding or fungal inoculation. In addition, we also identified protein-protein interactions among different homologs of MYB, bHLH and WDR. Finally, we generated transgenic spruce cell lines overexpressing four of the Norway spruce AtTT2 homologs and observed differential regulation of genes in the flavonoid pathway and flavonoid contents.
Collapse
Affiliation(s)
- Miguel Nemesio-Gorriz
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural SciencesUppsala, Sweden
- *Correspondence: Miguel Nemesio-Gorriz
| | - Peter B. Blair
- Department of Biology, University of Alabama at BirminghamBirmingham, AL, USA
| | - Kerstin Dalman
- Department of Chemistry and Biotechnology, Swedish University of Agricultural SciencesUppsala, Sweden
| | - Almuth Hammerbacher
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Jenny Arnerup
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural SciencesUppsala, Sweden
| | - Jan Stenlid
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural SciencesUppsala, Sweden
| | - Shahid M. Mukhtar
- Department of Biology, University of Alabama at BirminghamBirmingham, AL, USA
| | - Malin Elfstrand
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural SciencesUppsala, Sweden
| |
Collapse
|