1
|
Pazarlar S, Madriz-Ordeñana K, Thordal-Christensen H. Bacillus cereus EC9 protects tomato against Fusarium wilt through JA/ET-activated immunity. Front Plant Sci 2022; 13:1090947. [PMID: 36589090 PMCID: PMC9798288 DOI: 10.3389/fpls.2022.1090947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
The mechanisms of action and the limitations of effectiveness of natural biocontrol agents should be determined in order to convert them into end products that can be used in practice. Rhizosphere Bacillus spp. protect plants from various pathogens by displaying several modes of action. However, the ability of Bacillus spp. to control plant diseases depends on the interaction between the bacteria, host, and pathogen, and the environmental conditions. We found that soil drenching of tomato plants with the non-antifungal Bacillus cereus strain EC9 (EC9) enhances plant defense against Fusarium oxysporum f. sp. lycopersici (Fol). To study the involvement of plant defense-related phytohormones in the regulation of EC9-activated protection against Fol, we conducted plant bioassays in tomato genotypes impaired in salicylic acid (SA) accumulation, jasmonic acid (JA) biosynthesis, and ethylene (ET) production, and analyzed the transcript levels of pathways-related marker genes. Our results indicate that JA/ET-dependent signaling is required for EC9-mediated protection against Fol in tomato. We provide evidence that EC9 primes tomato plants for enhanced expression of proteinase inhibitor I (PI-I) and ethylene receptor4 (ETR4). Moreover, we demonstrated that EC9 induces callose deposition in tomato roots. Understanding the involvement of defense-related phytohormones in EC9-mediated defense against Fusarium wilt has increased our knowledge of interactions between non-antifungal plant defense-inducing rhizobacteria and plants.
Collapse
Affiliation(s)
- Sercan Pazarlar
- Department of Plant Protection, Faculty of Agriculture, Ege University, Izmir, Turkey
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
| | - Kenneth Madriz-Ordeñana
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
| | - Hans Thordal-Christensen
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
2
|
Madriz-Ordeñana K, Pazarlar S, Jørgensen HJL, Nielsen TK, Zhang Y, Nielsen KL, Hansen LH, Thordal-Christensen H. The Bacillus cereus Strain EC9 Primes the Plant Immune System for Superior Biocontrol of Fusarium oxysporum. Plants (Basel) 2022; 11:plants11050687. [PMID: 35270157 PMCID: PMC8912794 DOI: 10.3390/plants11050687] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 02/25/2022] [Accepted: 02/28/2022] [Indexed: 05/08/2023]
Abstract
Antibiosis is a key feature widely exploited to develop biofungicides based on the ability of biological control agents (BCAs) to produce fungitoxic compounds. A less recognised attribute of plant-associated beneficial microorganisms is their ability to stimulate the plant immune system, which may provide long-term, systemic self-protection against different types of pathogens. By using conventional antifungal in vitro screening coupled with in planta assays, we found antifungal and non-antifungal Bacillus strains that protected the ornamental plant Kalanchoe against the soil-borne pathogen Fusarium oxysporum in experimental and commercial production settings. Further examination of one antifungal and one non-antifungal strain indicated that high protection efficacy in planta did not correlate with antifungal activity in vitro. Whole-genome sequencing showed that the non-antifungal strain EC9 lacked the biosynthetic gene clusters associated with typical antimicrobial compounds. Instead, this bacterium triggers the expression of marker genes for the jasmonic and salicylic acid defence pathways, but only after pathogen challenge, indicating that this strain may protect Kalanchoe plants by priming immunity. We suggest that the stimulation of the plant immune system is a promising mode of action of BCAs for the development of novel biological crop protection products.
Collapse
Affiliation(s)
- Kenneth Madriz-Ordeñana
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Plant and Soil Science, University of Copenhagen, 1871 Frederiksberg, Denmark; (S.P.); (H.J.L.J.); (Y.Z.); (H.T.-C.)
- Correspondence:
| | - Sercan Pazarlar
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Plant and Soil Science, University of Copenhagen, 1871 Frederiksberg, Denmark; (S.P.); (H.J.L.J.); (Y.Z.); (H.T.-C.)
| | - Hans Jørgen Lyngs Jørgensen
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Plant and Soil Science, University of Copenhagen, 1871 Frederiksberg, Denmark; (S.P.); (H.J.L.J.); (Y.Z.); (H.T.-C.)
| | - Tue Kjærgaard Nielsen
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Microbial Ecology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark; (T.K.N.); (L.H.H.)
| | - Yingqi Zhang
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Plant and Soil Science, University of Copenhagen, 1871 Frederiksberg, Denmark; (S.P.); (H.J.L.J.); (Y.Z.); (H.T.-C.)
| | | | - Lars Hestbjerg Hansen
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Microbial Ecology and Biotechnology, University of Copenhagen, 1871 Frederiksberg, Denmark; (T.K.N.); (L.H.H.)
| | - Hans Thordal-Christensen
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre, Section for Plant and Soil Science, University of Copenhagen, 1871 Frederiksberg, Denmark; (S.P.); (H.J.L.J.); (Y.Z.); (H.T.-C.)
| |
Collapse
|
3
|
Madriz-Ordeñana K, Jørgensen HJL, Balan A, Sørensen DM, Nielsen KL, Thordal-Christensen H. Prevalence of Soil-borne Diseases in Kalanchoe blossfeldiana Reveals a Complex of Pathogenic and Opportunistic Fungi. Plant Dis 2019; 103:2634-2644. [PMID: 31339440 DOI: 10.1094/pdis-12-18-2252-re] [Citation(s) in RCA: 1] [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] [Indexed: 05/24/2023]
Abstract
Greenhouse cultivation of ornamentals is subjected to a high incidence of soil-borne fungal pathogens. In Kalanchoe, these pathogens are responsible for root and stem rot, and for infection of the vascular tissue. Well-known soil-borne pathogens are believed to cause these diseases. Yet, a systematized survey of these pathogens is lacking for Kalanchoe produced commercially. Here, we studied the occurrence of soil-borne fungal pathogens associated with cultivation of Kalanchoe in Denmark and production of cuttings and stock plants in greenhouse facilities located in Turkey and Vietnam. Molecular identification of pathogens complemented mycological identification and pathogenicity testing of the soil-borne fungal pathogens. This study revealed that the fungi Corynespora cassiicola, Thielaviopsis basicola, Fusarium solani, and F. oxysporum are the most prevalent pathogens associated with root and stem rotting and wilt of Kalanchoe under the conditions studied. Furthermore, the study showed that some of the pathogens are part of an infection complex comprising both primary and opportunistic fungal species. The fact that some of the pathogens were present in some regions, while absent in others, suggests how they move between greenhouse facilities on infected plant material. This study generated important information about the soil-borne fungal complex affecting Kalanchoe, which is useful for a better understanding of the biology of the disease and for designing control strategies.
Collapse
Affiliation(s)
- Kenneth Madriz-Ordeñana
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Hans Jørgen Lyngs Jørgensen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Andreea Balan
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Daniel Madriz Sørensen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | | | - Hans Thordal-Christensen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| |
Collapse
|
4
|
Liu C, Pedersen C, Schultz-Larsen T, Aguilar GB, Madriz-Ordeñana K, Hovmøller MS, Thordal-Christensen H. The stripe rust fungal effector PEC6 suppresses pattern-triggered immunity in a host species-independent manner and interacts with adenosine kinases. New Phytol 2016. [PMID: 27252028 DOI: 10.1111/nph.14034] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/25/2016] [Indexed: 05/20/2023]
Abstract
We identified a wheat stripe rust (Puccinia striiformis) effector candidate (PEC6) with pattern-triggered immunity (PTI) suppression function and its corresponding host target. PEC6 compromised PTI host species-independently. In Nicotiana benthamiana, it hampers reactive oxygen species (ROS) accumulation and callose deposition induced by Pseudomonas fluorescens. In Arabidopsis, plants expressing PEC6 were more susceptible to Pseudomonas syringae pv. tomato (Pto) DC3000 ΔAvrPto/ΔAvrPtoB. In wheat, PEC6-suppression of P. fluorescens-elicited PTI was revealed by the fact that it allowed activation of effector-triggered immunity by Pto DC3000. Knocking down of PEC6 expression by virus-mediated host-induced gene silencing decreased the number of rust pustules, uncovering PEC6 as an important pathogenicity factor. PEC6, overexpressed in plant cells without its signal peptide, was localized to the nucleus and cytoplasm. A yeast two-hybrid assay showed that PEC6 interacts with both wheat and Arabidopsis adenosine kinases (ADKs). Knocking down wheat ADK expression by virus-induced gene silencing reduced leaf growth and enhanced the number of rust pustules, indicating that ADK is important in plant development and defence. ADK plays essential roles in regulating metabolism, cytokinin interconversion and methyl transfer reactions, and our data propose a model where PEC6 may affect one of these processes by targeting ADK to favour fungal growth.
Collapse
Affiliation(s)
- Changhai Liu
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Carsten Pedersen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Torsten Schultz-Larsen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Geziel B Aguilar
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Kenneth Madriz-Ordeñana
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Mogens S Hovmøller
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, DK-4200, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| |
Collapse
|
5
|
Christensen AB, Cho BH, Næsby M, Gregersen PL, Brandt J, Madriz-Ordeñana K, Collinge DB, Thordal-Christensen H. The molecular characterization of two barley proteins establishes the novel PR-17 family of pathogenesis-related proteins. Mol Plant Pathol 2002; 3:135-44. [PMID: 20569319 DOI: 10.1046/j.1364-3703.2002.00105.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Summary Two barley (Hordeum vulgare L.) cDNA clones (pBH6-12 and pBH6-17) were isolated from a cDNA library prepared from leaves 6 h after inoculation with Blumeria graminis f.sp. hordei (Bgh). The two transcripts accumulate strongly in response to Bgh, peaking around 6, 15-24 and 48-96 h after inoculation, concomitant with fungal penetration attempts, hypersensitive response and fungal growth. The encoded proteins, HvPR-17a and HvPR-17b, belong to a new family of plant pathogenesis-related proteins, designated 'PR-17'. The family also include NtPRp27 from tobacco (Okushima et al., 2000, Plant Mol. Biol.42, 479-488) and WCI-5 from wheat (Görlach et al., 1996, Plant Cell8, 629-643), responsive to viral and fungal infection, respectively. Antisera were raised to HvPR-17a and HvPR-17b, and the proteins exhibit apparent molecular weights of 26 and 24 kDa, respectively. They accumulate in the mesophyll apoplast following Bgh-inoculation, as well as in the leaf epidermis, the only tissue to be invaded by the fungus. Several homologous plant proteins exist, and a highly conserved part of the members of this new protein family show similarity to the active site and to the peptide-binding groove of the exopeptidase 'aminopeptidase N' from eukaryotes and the endopeptidase 'thermolysin' from bacteria.
Collapse
Affiliation(s)
- Anders B Christensen
- Department of Plant Biology, Plant Pathology Section, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | | | | | | | | | | | | | | |
Collapse
|