1
|
Ishida K, Litomska A, Dunbar KL, Hertweck C. An Enzymatic Prodrug-like Route to Thio and Selenoamides. Angew Chem Int Ed Engl 2024:e202404243. [PMID: 38747847 DOI: 10.1002/anie.202404243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Indexed: 06/28/2024]
Abstract
6-Thioguanine (6TG) is a clinically used antitumor agent that was rationally designed as a DNA-targeting antimetabolite, but it also occurs naturally. 6TG is a critical virulence factor produced by Erwinia amylovorans, a notorious plant pathogen that causes fire blight of pome fruit trees. The biosynthesis of the rare thioamide metabolite involves an adenylating enzyme (YcfA) and a sulfur-mobilizing enzyme (YcfC), but the mechanism of sulfur transfer and putative intermediates have remained elusive. Through dissection and in vitro reconstitution of the thionation process using diverse substrates, we uncover an intermediate, prodrug-like thio-conjugate and elucidate the precise enzyme functions. YcfA not only adenylates GMP but also transfers the mercapto group of l-cysteine to the activated carbonyl. A designated C-S lyase (YcfC) then cleaves the resulting S-adduct to yield the thioamide. This pathway is distinct from canonical tRNA sulfur modifications and known enzymatic peptide thionations. By exploring a wide range of substrate surrogates, we exploited the tolerance of the enzyme pair to produce even a seleno analog. This study provides valuable insight into a previously unexplored area of bacterial thioamide formation and lays the groundwork for synthetic biology approaches to produce thioamide antimetabolites.
Collapse
Affiliation(s)
- Keishi Ishida
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Agnieszka Litomska
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Kyle L Dunbar
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743, Jena, Germany
| |
Collapse
|
2
|
Gdanetz K, Dobbins MR, Villani SM, Outwater CA, Slack SM, Nesbitt D, Svircev AM, Lauwers EM, Zeng Q, Cox KD, Sundin GW. Multisite Field Evaluation of Bacteriophages for Fire Blight Management: Incorporation of Ultraviolet Radiation Protectants and Impact on the Apple Flower Microbiome. PHYTOPATHOLOGY 2024; 114:1028-1038. [PMID: 37581441 DOI: 10.1094/phyto-04-23-0145-kc] [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: 08/16/2023]
Abstract
Fire blight, a disease of pome fruits caused by the bacterium Erwinia amylovora, has become increasingly difficult to manage after the emergence of streptomycin-resistant strains. Alternative antibiotics and copper are available; however, these chemicals have use restrictions in some countries and also can carry risks of phytotoxicity. Therefore, there is growing interest in biological-based management options, with bacteriophage (phages) showing promise, as these naturally occurring pathogens of bacteria are easy to isolate and grow. However, there are several technical challenges regarding the implementation of phage biocontrol in the field, as the viral molecules suffer from ultraviolet radiation (UVR) degradation and can die off rapidly in the absence of the host bacterium. In this work, we assessed the efficacy of Erwinia phages and a commercial phage product for blossom blight control in the field across multiple locations in the eastern United States. In these tests, disease control ranged from 0.0 to 82.7%, and addition of a UVR protectant only resulted in significantly increased disease control in 2 of 12 tests. We also analyzed microbial community population changes in response to phage application. Changes in bacterial community diversity metrics over time were not detected; however, relative abundances of target taxa were temporarily reduced after phage applications, indicating that these phage applications did not have deleterious effects on the flower microbiome. We have demonstrated that biological control of fire blight with phages is achievable, but a better understanding of phage-pathogen dynamics is required to optimize disease control efficacy.
Collapse
Affiliation(s)
- Kristi Gdanetz
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Madison R Dobbins
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Sara M Villani
- Department of Entomology and Plant Pathology, Mountain Horticulture and Crops Research and Extension Center, North Carolina State University, Mills River, NC 28759, U.S.A
| | - Cory A Outwater
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Suzanne M Slack
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
- Department of Horticulture, Iowa State University, Ames, IA 50011, U.S.A
| | - Darlene Nesbitt
- London Research and Development Centre, Agriculture and Agri-Food Canada, Vineland Station, ON, Canada L0R 2E0
| | - Antonet M Svircev
- London Research and Development Centre, Agriculture and Agri-Food Canada, Vineland Station, ON, Canada L0R 2E0
| | - Erin M Lauwers
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
- Northwest Michigan Horticulture Research Center, Michigan State University, Traverse City, MI 49694, U.S.A
| | - Quan Zeng
- Department of Plant Pathology and Ecology, CT Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06511, U.S.A
| | - Kerik D Cox
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456, U.S.A
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| |
Collapse
|
3
|
Din IU, Hu L, Jiang Y, Wei J, Afzal M, Sun L. Bacterial Lipopeptides Are Effective against Pear Fire Blight. Microorganisms 2024; 12:896. [PMID: 38792726 PMCID: PMC11123750 DOI: 10.3390/microorganisms12050896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024] Open
Abstract
Fire blight, a devastating disease caused by Erwinia amylovora, poses a significant threat to pear and apple trees in Xinjiang province, China. In an effort to combat this pathogen, we isolated 10 bacteria from various components of apple and crabapple trees and conducted screenings to assess their ability to inhibit E. amylovora in vitro. Through biochemical tests and partial 16S rRNA gene sequencing, we identified two promising strains, Priestia megaterium strain H1 and Bacillus subtilis strain I2. These strains were then evaluated for their efficacy in biocontrol under controlled laboratory conditions, focusing on immature fruits and leaves. Remarkably, all selected antagonists exhibited the capability to reduce the severity of the disease on both fruit and leaves. P. megaterium strain H1 and B. subtilis strain I2 exhibited significant reductions in disease incidence on both immature fruits and leaves compared to the control. Specifically, on immature fruits, they achieved reductions of 53.39% and 44.76%, respectively, while on leaves, they demonstrated reductions of 59.55% and 55.53%, respectively. Furthermore, during the study, we detected the presence of lipopeptides, including surfactin, iturins, bacillomycin D, and fengycins, in the methanol extract obtained from these two antagonistic bacteria using thin-layer chromatography (TLC). Based on the results obtained, B. subtilis strain I2 and P. megaterium strain H1 exhibit considerable potential for controlling fire blight. However, further evaluation of their efficacy under natural field conditions is essential to validate their practicality as a biocontrol method.
Collapse
Affiliation(s)
- Ihsan ud Din
- College of Life Sciences, Shihezi University, Shihezi 832003, China; (I.u.D.); (L.H.)
| | - Lina Hu
- College of Life Sciences, Shihezi University, Shihezi 832003, China; (I.u.D.); (L.H.)
| | - Yuan Jiang
- Agricultural Scientific Institute of 2nd Division of Xinjiang Production and Construction Corps, Tiemenguan 841005, China; (Y.J.); (J.W.)
| | - Jie Wei
- Agricultural Scientific Institute of 2nd Division of Xinjiang Production and Construction Corps, Tiemenguan 841005, China; (Y.J.); (J.W.)
| | - Muhammad Afzal
- College of Agriculture, South China Agricultural University, Guangzhou 510642, China;
| | - Li Sun
- College of Life Sciences, Shihezi University, Shihezi 832003, China; (I.u.D.); (L.H.)
| |
Collapse
|
4
|
Han J, Dong Z, Ji W, Lv W, Luo M, Fu B. From predator to protector: Myxococcus fulvus WCH05 emerges as a potent biocontrol agent for fire blight. Front Microbiol 2024; 15:1378288. [PMID: 38650871 PMCID: PMC11033317 DOI: 10.3389/fmicb.2024.1378288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/25/2024] [Indexed: 04/25/2024] Open
Abstract
Fire blight, caused by the Gram-negative bacterium Erwinia amylovora, poses a substantial threat to pome fruit production worldwide. Despite existing control strategies, a pressing need remains for sustainable and environmentally friendly fire blight management. Myxobacteria, renowned for their predatory behavior and potent enzymes, emerge as a groundbreaking biocontrol approach with significant potential. Here, we report the biocontrol potential of a novel Myxococcus fulvus WCH05, against E. amylovora. Using various in vitro and planta assays, we demonstrated the multifaceted biocontrol abilities of strain WCH05. In plate predation assays, strain WCH05 exhibited not only strong predation against E. amylovora but also broad-spectrum activities against other plant pathogenic bacteria. Pre-treatment with strain WCH05 significantly decreased pear blossom blight incidence in detached inflorescence assays, achieving a controlled efficacy of 76.02% that rivaled the antibiotic streptomycin (79.79%). In greenhouse trials, strain WCH05 effectively reduced the wilting rate and disease index in young pear seedlings, exhibiting both protective (73.68%) and curative (68.66%) control. Further investigation revealed that the biocontrol activity of strain WCH05 relies on both direct contact and extracellular enzyme secretion. While cell extracts lacked inhibitory activity, ammonium sulfate-precipitated secreted proteins displayed potent lytic activity against E. amylovora. Substrate spectrum analysis identified peptidases, lipases, and glycosidases among the secreted enzymes, suggesting their potential roles in pathogen degradation and biocontrol efficacy. This study presents the first evidence of Myxococcus fulvus WCH05 as a biocontrol agent against fire blight. Its potent predatory abilities and enzymatic arsenal highlight its potential for sustainable disease management in pome fruit production. Future research will focus on identifying and characterizing specific lytic enzymes and optimizing strain WCH05 application strategies for field efficacy.
Collapse
Affiliation(s)
- Jian Han
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| | - Zhiming Dong
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| | - Wenbo Ji
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| | - Wen Lv
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| | - Ming Luo
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| | - Benzhong Fu
- Department of Plant Pathology, College of Agronomy, Xinjiang Agriculture University/Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of Xinjiang Uygur Autonomous Region, Urumqi, China
- Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China
| |
Collapse
|
5
|
Xi H, Fu B, Sheng Q, Luo M, Sun L. Isolation and Characterization of a Lytic Bacteriophage RH-42-1 of Erwinia amylovora from Orchard Soil in China. Viruses 2024; 16:509. [PMID: 38675852 PMCID: PMC11054837 DOI: 10.3390/v16040509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/14/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
Fire blight, caused by the bacterium Erwinia amylovora, is a major threat to pear production worldwide. Bacteriophages, viruses that infect bacteria, are a promising alternative to antibiotics for controlling fire blight. In this study, we isolated a novel bacteriophage, RH-42-1, from Xinjiang, China. We characterized its biological properties, including host range, plaque morphology, infection dynamics, stability, and sensitivity to various chemicals. RH-42-1 infected several E. amylovora strains but not all. It produced clear, uniform plaques and exhibited optimal infectivity at a multiplicity of infection (MOI) of 1, reaching a high titer of 9.6 × 109 plaque-forming units (PFU)/mL. The bacteriophage had a short latent period (10 min), a burst size of 207 PFU/cell, and followed a sigmoidal one-step growth curve. It was stable at temperatures up to 60 °C but declined rapidly at higher temperatures. RH-42-1 remained viable within a pH range of 5 to 9 and was sensitive to extreme pH values. The bacteriophage demonstrates sustained activity upon exposure to ultraviolet radiation for 60 min, albeit with a marginal reduction. In our assays, it exhibited a certain level of resistance to 5% chloroform (CHCl3), 5% isopropanol (C3H8O), and 3% hydrogen peroxide (H2O2), which had little effect on its activity, whereas it showed sensitivity to 75% ethanol (C2H5OH). Electron microscopy revealed that RH-42-1 has a tadpole-shaped morphology. Its genome size is 14,942 bp with a GC content of 48.19%. Based on these characteristics, RH-42-1 was identified as a member of the Tectiviridae family, Alphatectivirus genus. This is the first report of a bacteriophage in this genus with activity against E. amylovora.
Collapse
Affiliation(s)
- Haishen Xi
- The Department of Plant Pathology, College of Agronomy at Xinjiang Agricultural University/Key Laboratory of Detection and Control of Agricultural and Forest Pests, Urumqi 830052, China; (H.X.); (B.F.)
- Ministry of Agriculture and Rural Affairs Key Laboratory for Pests and Diseases Control of Northwest Arid Oasis Agricultural Foreign Invasion Species, Urumqi 830052, China
| | - Benzhong Fu
- The Department of Plant Pathology, College of Agronomy at Xinjiang Agricultural University/Key Laboratory of Detection and Control of Agricultural and Forest Pests, Urumqi 830052, China; (H.X.); (B.F.)
- Ministry of Agriculture and Rural Affairs Key Laboratory for Pests and Diseases Control of Northwest Arid Oasis Agricultural Foreign Invasion Species, Urumqi 830052, China
| | - Qiang Sheng
- Xinjiang Bayingolin Mongolian Autonomous Prefecture Academy of Agricultural Sciences, Korla 841003, China;
| | - Ming Luo
- The Department of Plant Pathology, College of Agronomy at Xinjiang Agricultural University/Key Laboratory of Detection and Control of Agricultural and Forest Pests, Urumqi 830052, China; (H.X.); (B.F.)
- Ministry of Agriculture and Rural Affairs Key Laboratory for Pests and Diseases Control of Northwest Arid Oasis Agricultural Foreign Invasion Species, Urumqi 830052, China
| | - Liying Sun
- The Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China
| |
Collapse
|
6
|
Hassani MA, Cui Z, LaReau J, Huntley RB, Steven B, Zeng Q. Inter-species interactions between two bacterial flower commensals and a floral pathogen reduce disease incidence and alter pathogen activity. mBio 2024; 15:e0021324. [PMID: 38376185 PMCID: PMC10936193 DOI: 10.1128/mbio.00213-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Flowers are colonized by a diverse community of microorganisms that can alter plant health and interact with floral pathogens. Erwinia amylovora is a flower-inhabiting bacterium and a pathogen that infects different plant species, including Malus × domestica (apple). Previously, we showed that the co-inoculation of two bacterial strains, members of the genera Pseudomonas and Pantoea, isolated from apple flowers, reduced disease incidence caused by this floral pathogen. Here, we decipher the ecological interactions between the two flower-associated bacteria and E. amylovora in field experimentation and in vitro co-cultures. The two flower commensal strains did not competitively exclude E. amylovora from the stigma habitat, as both bacteria and the pathogen co-existed on the stigma of apple flowers and in vitro. This suggests that plant protection might be mediated by other mechanisms than competitive niche exclusion. Using a synthetic stigma exudation medium, ternary co-culture of the bacterial strains led to a substantial alteration of gene expression in both the pathogen and the two microbiota members. Importantly, the gene expression profiles for the ternary co-culture were not just additive from binary co-cultures, suggesting that some functions only emerged in multipartite co-culture. Additionally, the ternary co-culture of the strains resulted in a stronger acidification of the growth milieu than mono- or binary co-cultures, pointing to another emergent property of co-inoculation. Our study emphasizes the critical role of emergent properties mediated by inter-species interactions within the plant holobiont and their potential impact on plant health and pathogen behavior. IMPORTANCE Fire blight, caused by Erwinia amylovora, is one of the most important plant diseases of pome fruits. Previous work largely suggested plant microbiota commensals suppressed disease by antagonizing pathogen growth. However, inter-species interactions of multiple flower commensals and their influence on pathogen activity and behavior have not been well studied. Here, we show that co-inoculating two bacterial strains that naturally colonize the apple flowers reduces disease incidence. We further demonstrate that the interactions between these two microbiota commensals and the floral pathogen led to the emergence of new gene expression patterns and a strong alteration of the external pH, factors that may modify the pathogen's behavior. Our findings emphasize the critical role of emergent properties mediated by inter-species interactions between plant microbiota and plant pathogens and their impact on plant health.
Collapse
Affiliation(s)
- M. Amine Hassani
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Zhouqi Cui
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Jacquelyn LaReau
- Department of Environmental Science and Forestry, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Regan B. Huntley
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Blaire Steven
- Department of Environmental Science and Forestry, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| |
Collapse
|
7
|
Ibrahim N, Nesbitt D, Guo Q(T, Lin J, Svircev A, Wang Q, Weadge JT, Anany H. Improved Viability of Spray-Dried Pantoea agglomerans for Phage-Carrier Mediated Control of Fire Blight. Viruses 2024; 16:257. [PMID: 38400033 PMCID: PMC10893313 DOI: 10.3390/v16020257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens apple and pear production. It is mainly controlled by using antibiotics, such as streptomycin. Due to development of E. amylovora resistant strains and the excessive agricultural use of antibiotics, there is an increased awareness of the possibility of antibiotic resistance gene transfer to other microbes. Urgent development of biocontrol agents (BCAs) is needed that can be incorporated into integrated pest management programs as antibiotic alternatives. A novel phage-carrier system (PCS) that combines an antagonistic bacterium, Pantoea agglomerans, with its ability to act as a phage-carrier bacterium for Erwinia phages has been developed. The low viability of P. agglomerans cells following spray-drying (SD) has been a challenge for the industrial-scale production of this PCS. Here, an SD protocol was developed for P. agglomerans by modifying the growth medium and bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to the industrial-scale production of the BCA/PCS. The P. agglomerans viability was greater than 90% after SD and had a shelf life at 4 °C of 4 months, and reconstituted cells showed a 3 log reduction in E. amylovora counts with a pear disc assay.
Collapse
Affiliation(s)
- Nassereldin Ibrahim
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
- Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada;
- Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City 32897, Egypt
| | - Darlene Nesbitt
- Agriculture and Agri-Food Canada (AAFC), Vineland Station, ON L0R 2E0, Canada; (D.N.); (A.S.)
| | - Qian (Tracy) Guo
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
| | - Janet Lin
- National Microbiology Laboratory, National Health Agency, 110 Stone Rd. W., Guelph, ON N1G 3W4, Canada;
| | - Antonet Svircev
- Agriculture and Agri-Food Canada (AAFC), Vineland Station, ON L0R 2E0, Canada; (D.N.); (A.S.)
| | - Qi Wang
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
| | - Joel T. Weadge
- Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada;
| | - Hany Anany
- Agriculture and Agri-Food Canada (AAFC), Guelph Research and Development Centre (GRDC), 93 Stone Rd W., Guelph, ON N1G 5C9, Canada; (N.I.); (Q.G.); (Q.W.)
- Food Science Department, University of Guelph, Guelph, ON N1G 2W1, Canada
| |
Collapse
|
8
|
Yang HW, Thapa R, Johnson K, DuPont ST, Khan A, Zhao Y. Examination of Large Chromosomal Inversions in the Genome of Erwinia amylovora Strains Reveals Worldwide Distribution and North America-Specific Types. PHYTOPATHOLOGY 2023; 113:2174-2186. [PMID: 36935376 DOI: 10.1094/phyto-01-23-0004-sa] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Erwinia amylovora is a relatively homogeneous species with low genetic diversity at the nucleotide level. However, phenotypic differences and genomic structural variations among E. amylovora strains have been documented. In this study, we identified 10 large chromosomal inversion (LCI) types in the Spiraeoideae-infecting (SI) E. amylovora strains by combining whole genome sequencing and PCR-based molecular markers. It was found that LCIs were mainly caused by homologous recombination events among seven rRNA operons (rrns) in SI E. amylovora strains. Although ribotyping results identified inter- and intra-variations in the internal transcribed spacer (ITS1 and ITS2) regions among rrns, LCIs tend to occur between rrns transcribed in the opposite directions and with the same tRNA content (tRNA-Glu or tRNA-Ile/Ala) in ITS1. Based on the LCI types, physical/estimated replichore imbalance (PRI/ERI) was examined and calculated. Among the 117 SI strains evaluated, the LCI types of Ea1189, CFBP1430, and Ea273 were the most common, with ERI values at 1.31, 7.87, and 4.47°, respectively. These three LCI types had worldwide distribution, whereas the remaining seven LCI types were restricted to North America (or certain regions of the United States). Our results indicated ongoing chromosomal recombination events in the SI E. amylovora population and showed that LCI events are mostly symmetrical, keeping the ERI less than 15°. These findings provide initial evidence about the prevalence of certain LCI types in E. amylovora strains, how LCI occurs, and its potential evolutionary advantage and history, which might help track the movement of the pathogen.
Collapse
Affiliation(s)
- Ho-Wen Yang
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802
| | - Ranjita Thapa
- School of Integrative Plant Science Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Kenneth Johnson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | | | - Awais Khan
- School of Integrative Plant Science Plant Pathology and Plant-Microbe Biology, Cornell University, Geneva, NY 14456
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802
- Department of Plant Pathology, WSU-IAREC, Prosser, WA 99350
| |
Collapse
|
9
|
Yuan X, Gdanetz K, Outwater CA, Slack SM, Sundin GW. Evaluation of Plant Defense Inducers and Plant Growth Regulators for Fire Blight Management Using Transcriptome Studies and Field Assessments. PHYTOPATHOLOGY 2023; 113:2152-2164. [PMID: 37399041 DOI: 10.1094/phyto-04-23-0147-kc] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Fire blight, caused by Erwinia amylovora, is a destructive disease of pome fruit trees. In the United States, apple and pear growers rely on applications of copper and antibiotics during bloom to control fire blight, but such methods have already led to regional instances of resistance. In this study, we used transcriptome analyses and field trials to evaluate the effectiveness of three commercially available plant defense elicitors and one plant growth regulator for fire blight management. Our data indicated that foliar applications of acibenzolar-S-methyl (ASM; Actigard 50WG) triggered a strong defense-related response in apple leaves, whereas applications of Bacillus mycoides isolate J (LifeGard WG) or Reynoutria sachalinensis extract (Regalia) did not. Genes upregulated by ASM were enriched in the biological processes associated with plant immunity, such as defense response and protein phosphorylation. The expression of several pathogenesis-related (PR) genes was induced by ASM as well. Surprisingly, many differentially expressed genes in ASM-treated apple leaves overlapped with those induced by treatment with prohexadione-calcium (ProCa; Apogee), a plant growth regulator that suppresses shoot elongation. Further analysis suggested that ProCa likely acts similarly to ASM to stimulate plant immunity because genes involved in plant defense were shared and significantly upregulated (more than twofold) by both treatments. Our field trials agreed with the transcriptome study, demonstrating that ASM and ProCa exhibit the best control performance relative to the other biopesticides. Taken together, these data are pivotal for the understanding of plant response and shed light on future improvements of strategies for fire blight management.
Collapse
Affiliation(s)
- Xiaochen Yuan
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011
| | - Kristi Gdanetz
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Cory A Outwater
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Suzanne M Slack
- Department of Horticulture, Iowa State University, Ames, IA 50011
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| |
Collapse
|
10
|
Yuan X, Sundin GW, Zeng Q, Johnson KB, Cox KD, Yu M, Huang J, Yang CH. Erwinia amylovora Type III Secretion System Inhibitors Reduce Fire Blight Infection Under Field Conditions. PHYTOPATHOLOGY 2023; 113:2197-2204. [PMID: 37344783 DOI: 10.1094/phyto-04-23-0111-sa] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2023]
Abstract
Fire blight, caused by Erwinia amylovora, is an economically important disease in apples and pears worldwide. This pathogen relies on the type III secretion system (T3SS) to cause disease. Compounds that inhibit the function of the T3SS (T3SS inhibitors) have emerged as alternative strategies for bacterial plant disease management, as they block bacterial virulence without affecting growth, unlike traditional antibiotics. In this study, we investigated the mode of action of a T3SS inhibitor named TS108, a plant phenolic acid derivative, in E. amylovora. We showed that adding TS108 to an in vitro culture of E. amylovora repressed the expression of several T3SS regulon genes, including the master regulator gene hrpL. Further studies demonstrated that TS108 negatively regulates CsrB, a global regulatory small RNA, at the posttranscriptional level, resulting in a repression of hrpS, which encodes a key activator of hrpL. Additionally, TS108 has no impact on the expression of T3SS in Dickeya dadantii or Pseudomonas aeruginosa, suggesting that its inhibition of the E. amylovora T3SS is likely species specific. To better evaluate the performance of T3SS inhibitors in fire blight management, we conducted five independent field experiments in four states (Michigan, New York, Oregon, and Connecticut) from 2015 to 2022 and observed reductions in blossom blight incidence as high as 96.7% compared with untreated trees. In summary, the T3SS inhibitors exhibited good efficacy against fire blight.
Collapse
Affiliation(s)
- Xiaochen Yuan
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
| | - Kenneth B Johnson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Kerik D Cox
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY 14456
| | - Manda Yu
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
| | - Jian Huang
- T3 Bioscience, Lapham Hall 181, Milwaukee, WI 53211
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
| |
Collapse
|
11
|
Jo SJ, Kim SG, Park J, Lee YM, Giri SS, Lee SB, Jung WJ, Hwang MH, Park JH, Roh E, Park SC. Optimizing the formulation of Erwinia bacteriophages for improved UV stability and adsorption on apple leaves. Heliyon 2023; 9:e22034. [PMID: 38034629 PMCID: PMC10682131 DOI: 10.1016/j.heliyon.2023.e22034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 10/30/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
Fire blight is a bacterial disease that affects plants of the Rosaceae family and causes significant economic losses worldwide. Although antibiotics have been used to control the disease, concerns about their environmental impact and the potential to promote antibiotic resistance have arisen. Bacteriophages are being investigated as an alternative to antibiotics; however, their efficacy can be affected by environmental stresses, such as UV radiation. In this study, we optimized the formulation of Erwinia phages to enhance their stability in the field, focusing on improving their UV stability and adsorption using adjuvants. Our results confirmed that 4.5 % polysorbate 80 and kaolin improve phage stability under UV stress, resulting in an 80 % increase in PFU value and improved UV protection efficacy. Adsorption assays also demonstrated that polysorbate 80 and kaolin improved the absorption efficiency, with phages detected in plant for up to two weeks. These findings demonstrate the effectiveness of the auxiliary formulation of Erwinia bacteriophages against environmental stress.
Collapse
Affiliation(s)
- Su Jin Jo
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sang Guen Kim
- Department of Biological Sciences, Kyonggi University, Suwon, 16227, Republic of Korea
| | - Jungkum Park
- Crop Protection Division, National Institute of Agriculture Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Young Min Lee
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sib Sankar Giri
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Bin Lee
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Won Joon Jung
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Mae Hyun Hwang
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jae Hong Park
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eunjung Roh
- Crop Protection Division, National Institute of Agriculture Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Se Chang Park
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| |
Collapse
|
12
|
Haegeman A, Foucart Y, De Jonghe K, Goedefroit T, Al Rwahnih M, Boonham N, Candresse T, Gaafar YZA, Hurtado-Gonzales OP, Kogej Zwitter Z, Kutnjak D, Lamovšek J, Lefebvre M, Malapi M, Mavrič Pleško I, Önder S, Reynard JS, Salavert Pamblanco F, Schumpp O, Stevens K, Pal C, Tamisier L, Ulubaş Serçe Ç, van Duivenbode I, Waite DW, Hu X, Ziebell H, Massart S. Looking beyond Virus Detection in RNA Sequencing Data: Lessons Learned from a Community-Based Effort to Detect Cellular Plant Pathogens and Pests. PLANTS (BASEL, SWITZERLAND) 2023; 12:2139. [PMID: 37299118 PMCID: PMC10255714 DOI: 10.3390/plants12112139] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/12/2023]
Abstract
High-throughput sequencing (HTS), more specifically RNA sequencing of plant tissues, has become an indispensable tool for plant virologists to detect and identify plant viruses. During the data analysis step, plant virologists typically compare the obtained sequences to reference virus databases. In this way, they are neglecting sequences without homologies to viruses, which usually represent the majority of sequencing reads. We hypothesized that traces of other pathogens might be detected in this unused sequence data. In the present study, our goal was to investigate whether total RNA-seq data, as generated for plant virus detection, is also suitable for the detection of other plant pathogens and pests. As proof of concept, we first analyzed RNA-seq datasets of plant materials with confirmed infections by cellular pathogens in order to check whether these non-viral pathogens could be easily detected in the data. Next, we set up a community effort to re-analyze existing Illumina RNA-seq datasets used for virus detection to check for the potential presence of non-viral pathogens or pests. In total, 101 datasets from 15 participants derived from 51 different plant species were re-analyzed, of which 37 were selected for subsequent in-depth analyses. In 29 of the 37 selected samples (78%), we found convincing traces of non-viral plant pathogens or pests. The organisms most frequently detected in this way were fungi (15/37 datasets), followed by insects (13/37) and mites (9/37). The presence of some of the detected pathogens was confirmed by independent (q)PCRs analyses. After communicating the results, 6 out of the 15 participants indicated that they were unaware of the possible presence of these pathogens in their sample(s). All participants indicated that they would broaden the scope of their bioinformatic analyses in future studies and thus check for the presence of non-viral pathogens. In conclusion, we show that it is possible to detect non-viral pathogens or pests from total RNA-seq datasets, in this case primarily fungi, insects, and mites. With this study, we hope to raise awareness among plant virologists that their data might be useful for fellow plant pathologists in other disciplines (mycology, entomology, bacteriology) as well.
Collapse
Affiliation(s)
- Annelies Haegeman
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Yoika Foucart
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Kris De Jonghe
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Thomas Goedefroit
- Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium
| | - Maher Al Rwahnih
- Foundation Plant Services, Department of Plant Pathology, University of California, Davis, CA 95616, USA
| | - Neil Boonham
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
| | - Thierry Candresse
- UMR 1332 Biologie du Fruit et Pathologie, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Bordeaux, 33882 Villenave-d’Ornon, France
| | - Yahya Z. A. Gaafar
- Centre for Plant Health, Canadian Food Inspection Agency, 8801 East Saanich Road, North Saanich, BC V8L 1H3, Canada
| | - Oscar P. Hurtado-Gonzales
- Plant Germplasm Quarantine Program, Animal and Plant Health Inspection Service, United States Department of Agriculture (USDA-APHIS), Beltsville, ML 20705, USA
| | - Zala Kogej Zwitter
- Department of Biotechnology and Systems Biology, National Institute of Biology (NIB), 1000 Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, 1000 Ljubljana, Slovenia
| | - Denis Kutnjak
- Department of Biotechnology and Systems Biology, National Institute of Biology (NIB), 1000 Ljubljana, Slovenia
| | - Janja Lamovšek
- Plant Protection Department, Agricultural Institute of Slovenia (KIS), 1000 Ljubljana, Slovenia
| | - Marie Lefebvre
- UMR 1332 Biologie du Fruit et Pathologie, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Bordeaux, 33882 Villenave-d’Ornon, France
| | - Martha Malapi
- Biotechnology Risk Analysis Program, Animal and Plant Health Inspection Service, United States Department of Agriculture (USDA-APHIS), Riverdale, ML 20737, USA
| | - Irena Mavrič Pleško
- Plant Protection Department, Agricultural Institute of Slovenia (KIS), 1000 Ljubljana, Slovenia
| | - Serkan Önder
- Department of Plant Protection, Faculty of Agriculture, Eskişehir Osmangazi University, Odunpazarı, Eskişehir 26160, Turkey
| | | | | | - Olivier Schumpp
- Department of Plant Protection, Agroscope, 1260 Nyon, Switzerland
| | - Kristian Stevens
- Foundation Plant Services, Department of Plant Pathology, University of California, Davis, CA 95616, USA
| | - Chandan Pal
- Zespri International Limited, 400 Maunganui Road, Mount Maunganui 3116, New Zealand
| | - Lucie Tamisier
- Unités GAFL et Pathologie Végétale, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 84143 Montfavet, France
| | - Çiğdem Ulubaş Serçe
- Department of Plant Production and Technologies, Faculty of Agricultural Sciences and Technologies, Niğde Ömer Halisdemir University, 51240 Niğde, Turkey
| | - Inge van Duivenbode
- Dutch General Inspection Service for Agricultural Seed and Seed Potatoes (NAK), Randweg 14, 8304 AS Emmeloord, The Netherlands
| | - David W. Waite
- Plant Health and Environment Laboratory, Ministry for Primary Industries, Auckland 1140, New Zealand
| | - Xiaojun Hu
- Plant Germplasm Quarantine Program, Animal and Plant Health Inspection Service, United States Department of Agriculture (USDA-APHIS), Beltsville, ML 20705, USA
| | - Heiko Ziebell
- Institute for Epidemiology and Pathogen Diagnostics, Federal Research Centre for Cultivated Plants, Julius Kühn Institute (JKI), Messeweg 11-12, 38104 Braunschweig, Germany
| | - Sébastien Massart
- Plant Pathology Laboratory, University of Liège, Gembloux Agro-Bio Tech, TERRA, 5030 Gembloux, Belgium
| |
Collapse
|
13
|
Parmagnani AS, Kanchiswamy CN, Paponov IA, Bossi S, Malnoy M, Maffei ME. Bacterial Volatiles (mVOC) Emitted by the Phytopathogen Erwinia amylovora Promote Arabidopsis thaliana Growth and Oxidative Stress. Antioxidants (Basel) 2023; 12:antiox12030600. [PMID: 36978848 PMCID: PMC10045578 DOI: 10.3390/antiox12030600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 02/21/2023] [Accepted: 02/25/2023] [Indexed: 03/04/2023] Open
Abstract
Phytopathogens are well known for their devastating activity that causes worldwide significant crop losses. However, their exploitation for crop welfare is relatively unknown. Here, we show that the microbial volatile organic compound (mVOC) profile of the bacterial phytopathogen, Erwinia amylovora, enhances Arabidopsis thaliana shoot and root growth. GC-MS head-space analyses revealed the presence of typical microbial volatiles, including 1-nonanol and 1-dodecanol. E. amylovora mVOCs triggered early signaling events including plasma transmembrane potential Vm depolarization, cytosolic Ca2+ fluctuation, K+-gated channel activity, and reactive oxygen species (ROS) and nitric oxide (NO) burst from few minutes to 16 h upon exposure. These early events were followed by the modulation of the expression of genes involved in plant growth and defense responses and responsive to phytohormones, including abscisic acid, gibberellin, and auxin (including the efflux carriers PIN1 and PIN3). When tested, synthetic 1-nonanol and 1-dodecanol induced root growth and modulated genes coding for ROS. Our results show that E. amylovora mVOCs affect A. thaliana growth through a cascade of early and late signaling events that involve phytohormones and ROS.
Collapse
Affiliation(s)
- Ambra S. Parmagnani
- Department of Life Sciences and Systems Biology, University of Turin, Via Quarello 15/a, 10135 Turin, Italy
| | | | - Ivan A. Paponov
- Department of Food Science, Aarhus University, 8200 Aarhus, Denmark
| | - Simone Bossi
- Department of Life Sciences and Systems Biology, University of Turin, Via Quarello 15/a, 10135 Turin, Italy
| | - Mickael Malnoy
- Research and Innovation Centre, Edmund Mach Foundation, Via Edmund Mach 1, 38098 San Michele all’Adige, Italy
| | - Massimo E. Maffei
- Department of Life Sciences and Systems Biology, University of Turin, Via Quarello 15/a, 10135 Turin, Italy
- Correspondence: ; Tel.: +39-011-670-5967
| |
Collapse
|
14
|
Khan A, Korban SS. Breeding and genetics of disease resistance in temperate fruit trees: challenges and new opportunities. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:3961-3985. [PMID: 35441862 DOI: 10.1007/s00122-022-04093-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Climate change, large monocultures of disease-susceptible cultivars, overuse of pesticides, and the emergence of new pathogens or pathogenic strains causing economic losses are all major threats to our environment, health, food, and nutritional supply. Temperate tree fruit crops belonging to the Rosaceae family are the most economically important and widely grown fruit crops. These long-lived crops are under attack from many different pathogens, incurring major economic losses. Multiple chemical sprays to control various diseases annually is a common practice, resulting in significant input costs, as well as environmental and health concerns. Breeding for disease resistance has been undertaken primarily in pome fruit crops (apples and pears) for a few fungal and bacterial diseases, and to a lesser extent in some stone fruit crops. These breeding efforts have taken multiple decades due to the biological constraints and complex genetics of these tree fruit crops. Over the past couple of decades, major advances have been made in genetic and physical mapping, genomics, biotechnology, genome sequencing, and phenomics, along with accumulation of large germplasm collections in repositories. These valuable resources offer opportunities to make significant advances in greatly reducing the time needed to either develop new cultivars or modify existing economic cultivars for enhanced resistance to multiple diseases. This review will cover current knowledge, challenges, and opportunities in breeding for disease resistance in temperate tree fruit crops.
Collapse
Affiliation(s)
- Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA.
| | - Schuyler S Korban
- Department of Natural Sciences and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| |
Collapse
|
15
|
Kim YS, Ngo MT, Kim B, Han JW, Song J, Park MS, Choi GJ, Kim H. Biological Control Potential of Penicillium brasilianum against Fire Blight Disease. THE PLANT PATHOLOGY JOURNAL 2022; 38:461-471. [PMID: 36221918 PMCID: PMC9561163 DOI: 10.5423/ppj.oa.06.2022.0076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 06/16/2023]
Abstract
Erwinia amylovora is a causative pathogen of fire blight disease, affecting apple, pear, and other rosaceous plants. Currently, management of fire blight relies on cultural and chemical practices, whereas it has been known that few biological resources exhibit disease control efficacy against the fire blight. In the current study, we found that an SFC20201208-M01 fungal isolate exhibits antibacterial activity against E. amylovora TS3128, and the isolate was identified as a Penicillium brasilianum based on the β-tubulin (BenA) gene sequence. To identify active compounds from the P. brasilianum culture, the culture filtrate was partitioned with ethyl acetate and n-butanol sequentially. From the ethyl acetate layer, we identified two new compounds (compounds 3-4) and two known compounds (compounds 1-2) based on spectroscopic analyses and comparison with literature data. Of these active compounds, penicillic acid (1) exhibited promising antibacterial activity against E. amylovora TS3128 with a minimal inhibitory concentration value of 25 μg/ml. When culture filtrate and penicillic acid (125 μg/ml) were applied onto Chinese pearleaf crab apple seedlings prior to inoculation of E. amylovora TS3128, the development of fire blight disease was effectively suppressed in the treated plants. Our results provide new insight into the biocontrol potential of P. brasilianum SFC20201208-M01 with an active ingredient to control fire blight.
Collapse
Affiliation(s)
- Yeong Seok Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
- Division of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113,
Korea
| | - Men Thi Ngo
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
- Division of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113,
Korea
| | - Bomin Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
- Division of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113,
Korea
| | - Jae Woo Han
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
| | - Jaekyeong Song
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365,
Korea
| | - Myung Soo Park
- Department of School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
| | - Gyung Ja Choi
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
- Division of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113,
Korea
| | - Hun Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon 34114,
Korea
- Division of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon 34113,
Korea
| |
Collapse
|
16
|
Yuan X, Eldred LI, Sundin GW. Exopolysaccharides amylovoran and levan contribute to sliding motility in the fire blight pathogen Erwinia amylovora. Environ Microbiol 2022; 24:4738-4754. [PMID: 36054324 PMCID: PMC9826367 DOI: 10.1111/1462-2920.16193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/31/2022] [Indexed: 01/11/2023]
Abstract
Erwinia amylovora, the causative agent of fire blight, uses flagella-based motilities to translocate to host plant natural openings; however, little is known about how this bacterium migrates systemically in the apoplast. Here, we reveal a novel surface motility mechanism, defined as sliding, in E. amylovora. Deletion of flagella assembly genes did not affect this movement, whereas deletion of biosynthesis genes for the exopolysaccharides (EPSs) amylovoran and levan resulted in non-sliding phenotypes. Since EPS production generates osmotic pressure that potentially powers sliding, we validated this mechanism by demonstrating that water potential positively contributes to sliding. In addition, no sliding was observed when the water potential of the surface was lower than -0.5 MPa. Sliding is a passive motility mechanism. We further show that the force of gravity plays a critical role in directing E. amylovora sliding on unconfined surfaces but has a negligible effect when cells are sliding in confined microcapillaries, in which EPS-dependent osmotic pressure acts as the main force. Although amylovoran and levan are both required for sliding, we demonstrate that they exhibit different roles in bacterial communities. In summary, our study provides fundamental knowledge for a better understanding of mechanisms that drive bacterial sliding motility.
Collapse
Affiliation(s)
- Xiaochen Yuan
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Lauren I. Eldred
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| |
Collapse
|
17
|
Lee J, Choi J, Lee J, Cho Y, Kang IJ, Han SW. Comparing Protein Expression in Erwinia amylovora Strain TS3128 Cultured under Three Sets of Environmental Conditions. THE PLANT PATHOLOGY JOURNAL 2022; 38:410-416. [PMID: 35953061 PMCID: PMC9372105 DOI: 10.5423/ppj.nt.05.2022.0073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Erwinia amylovora, the causal agent of fire-blight disease in apple and pear trees, was first isolated in South Korea in 2015. Although numerous studies, including omics analyses, have been conducted on other strains of E. amylovora, studies on South Korean isolates remain limited. In this study, we conducted a comparative proteomic analysis of the strain TS3128, cultured in three media representing different growth conditions. Proteins related to virulence, type III secretion system, and amylovoran production, were more abundant under minimal conditions than in rich conditions. Additionally, various proteins associated with energy production, carbohydrate metabolism, cell wall/membrane/envelope biogenesis, and ion uptake were identified under minimal conditions. The strain TS3128 expresses these proteins to survive in harsh environments. These findings contribute to understanding the cellular mechanisms driving its adaptations to different environmental conditions and provide proteome profiles as reference for future studies on the virulence and adaptation mechanisms of South Korean strains.
Collapse
Affiliation(s)
- Jongchan Lee
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546,
Korea
| | - Junhyeok Choi
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546,
Korea
| | - Jeongwook Lee
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546,
Korea
| | - Yongmin Cho
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546,
Korea
| | - In-Jeong Kang
- Division of Crop Cultivation and Environment Research, National Institute of Crop Science, Suwon 16613,
Korea
| | - Sang-Wook Han
- Department of Plant Science and Technology, Chung-Ang University, Anseong 17546,
Korea
| |
Collapse
|
18
|
Albanese D, Cainelli C, Gualandri V, Larger S, Pindo M, Donati C. Genome sequencing provides new insights on the distribution of Erwinia amylovora lineages in northern Italy. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:584-590. [PMID: 35484918 PMCID: PMC9544390 DOI: 10.1111/1758-2229.13074] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Erwinia amylovora is a Gram-negative bacterium that colonizes a wide variety of plant species causing recurrent local outbreaks of fire blight in crops of the Rosaceae family. Recent genomic surveys have documented the limited genomic diversity of this species, possibly related to a recent evolutionary bottleneck and a strong correlation between geography and phylogenetic structure of the species. Despite its economic importance, little is known about the genetic variability of co-circulating strains during local outbreaks. Here, we report the genome sequences of 82 isolates of E. amylovora, collected from different host plants in a period of 16 years in Trentino, a small region in the Northeastern Italian Alps that has been characterized by recurrent outbreaks of fire blight in apple orchards. While the genome isolated before 2018 are closely related to other strains already present in Europe, we found a novel subclade composed only by isolates that were sampled starting from 2018 and demonstrate that the endemic population of this pathogen can be composed by mixture of strains.
Collapse
Affiliation(s)
- Davide Albanese
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Christian Cainelli
- Center for Technology Transfer, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Valeria Gualandri
- Center for Technology Transfer, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
- Center of Agriculture, Food and Environment (C3A)University of TrentoTrentoItaly
| | - Simone Larger
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Massimo Pindo
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| | - Claudio Donati
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1San Michele all'Adige38010Italy
| |
Collapse
|
19
|
Slack SM, Schachterle JK, Sweeney EM, Kharadi RR, Peng J, Botti-Marino M, Bardaji L, Pochubay EA, Sundin GW. In-Orchard Population Dynamics of Erwinia amylovora on Apple Flower Stigmas. PHYTOPATHOLOGY 2022; 112:1214-1225. [PMID: 35021859 DOI: 10.1094/phyto-01-21-0018-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Populations of the fire blight pathogen Erwinia amylovora Ea110 on apple flower stigmas were tracked over the course of apple bloom in field studies conducted between 2016 and 2019. In 18 of 23 experiments, flower stigmas inoculated on the first day of opening were found to harbor large (106 to 107 cells per flower) populations of E. amylovora when assessed 3 to 5 days postinoculation. However, populations inoculated on stigmas of flowers that were already open for 3 days did not reach 106 cells per flower, and populations inoculated on stigmas of flowers that were already open for 5 days never exceeded 104 cells per flower. During this study, ≥10-fold increases in E. amylovora stigma populations in a 24-h time period (termed population surges) were observed on 34.8, 20.0, and 4.0% of possible days on 1-, 3-, and 5-day-open flowers, respectively. Population surges occurred on days with average temperatures as high as 24.5 and as low as 6.1°C. Experiments incorporating more frequent sampling during days and overnight revealed that many population surges occurred between 10:00 p.m. and 2:00 a.m. A Pearson's correlation analysis of weather parameters occurring during surge events indicated that population surges were significantly associated with situations in which overnight temperatures increased or remained constant, in which wind speed decreased, and in which relative humidity increased. This study refines our knowledge of E. amylovora population dynamics and further indicates that E. amylovora is able to infect flowers during exposure to colder field temperatures than previously reported.
Collapse
Affiliation(s)
- Suzanne M Slack
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Jeffery K Schachterle
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Emma M Sweeney
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Roshni R Kharadi
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Jingyu Peng
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Megan Botti-Marino
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Leire Bardaji
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, 31192 Mutilva Baja, Spain
| | - Emily A Pochubay
- Northwest Michigan Horticultural Research Center, Traverse City, MI 49684, U.S.A
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| |
Collapse
|
20
|
Schachterle JK, Gdanetz K, Pandya I, Sundin GW. Identification of novel virulence factors in Erwinia amylovora through temporal transcriptomic analysis of infected apple flowers under field conditions. MOLECULAR PLANT PATHOLOGY 2022; 23:855-869. [PMID: 35246928 PMCID: PMC9104256 DOI: 10.1111/mpp.13199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
The enterobacterial pathogen Erwinia amylovora uses multiple virulence-associated traits to cause fire blight, a devastating disease of apple and pear trees. Many virulence-associated phenotypes have been studied that are critical for virulence and pathogenicity. Despite the in vitro testing that has revealed how these systems are transcriptionally regulated, information on when and where in infected tissues these genes are being expressed is lacking. Here, we used a high-throughput sequencing approach to characterize the transcriptome of E. amylovora during disease progression on apple flowers under field infection conditions. We report that type III secretion system genes and flagellar genes are strongly co-expressed. Likewise, genes involved in biosynthesis of the exopolysaccharide amylovoran and sorbitol utilization had similar expression patterns. We further identified a group of 16 genes whose expression is increased and maintained at high levels throughout disease progression across time and tissues. We chose five of these genes for mutational analysis and observed that deletion mutants lacking these genes all display reduced symptom development on apple shoots. Furthermore, these induced genes were over-represented for genes involved in sulphur metabolism and cycling, suggesting the possibility of an important role for maintenance of oxidative homeostasis during apple flower infection.
Collapse
Affiliation(s)
- Jeffrey K. Schachterle
- Genetics and Genome Sciences ProgramMichigan State UniversityEast LansingMIUSA
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMIUSA
- Present address:
USDAARS, Cereal Crops Research UnitFargoNDUSA
| | - Kristi Gdanetz
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMIUSA
| | - Ishani Pandya
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMIUSA
| | - George W. Sundin
- Genetics and Genome Sciences ProgramMichigan State UniversityEast LansingMIUSA
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMIUSA
| |
Collapse
|
21
|
The RNA-Binding Protein ProQ Impacts Exopolysaccharide Biosynthesis and Second Messenger Cyclic di-GMP Signaling in the Fire Blight Pathogen Erwinia amylovora. Appl Environ Microbiol 2022; 88:e0023922. [PMID: 35416685 DOI: 10.1128/aem.00239-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Erwinia amylovora is a plant-pathogenic bacterium that causes fire blight disease in many economically important plants, including apples and pears. This bacterium produces three exopolysaccharides (EPSs), amylovoran, levan, and cellulose, and forms biofilms in host plant vascular tissues, which are crucial for pathogenesis. Here, we demonstrate that ProQ, a conserved bacterial RNA chaperone, was required for the virulence of E. amylovora in apple shoots and for biofilm formation in planta. In vitro experiments revealed that the deletion of proQ increased the production of amylovoran and cellulose. Prc is a putative periplasmic protease, and the prc gene is located adjacent to proQ. We found that Prc and the associated lipoprotein NlpI negatively affected amylovoran production, whereas Spr, a peptidoglycan hydrolase degraded by Prc, positively regulated amylovoran. Since the prc promoter is likely located within proQ, our data showed that proQ deletion significantly reduced the prc mRNA levels. We used a genome-wide transposon mutagenesis experiment to uncover the involvement of the bacterial second messenger c-di-GMP in ProQ-mediated cellulose production. The deletion of proQ resulted in elevated intracellular c-di-GMP levels and cellulose production, which were restored to wild-type levels by deleting genes encoding c-di-GMP biosynthesis enzymes. Moreover, ProQ positively affected the mRNA levels of genes encoding c-di-GMP-degrading phosphodiesterase enzymes via a mechanism independent of mRNA decay. In summary, our study revealed a detailed function of E. amylovora ProQ in coordinating cellulose biosynthesis and, for the first time, linked ProQ with c-di-GMP metabolism and also uncovered a role of Prc in the regulation of amylovoran production. IMPORTANCE Fire blight, caused by the bacterium Erwinia amylovora, is an important disease affecting many rosaceous plants, including apple and pear, that can lead to devastating economic losses worldwide. Similar to many xylem-invading pathogens, E. amylovora forms biofilms that rely on the production of exopolysaccharides (EPSs). In this paper, we identified the RNA-binding protein ProQ as an important virulence regulator. ProQ played a central role in controlling the production of EPSs and participated in the regulation of several conserved bacterial signal transduction pathways, including the second messenger c-di-GMP and the periplasmic protease Prc-mediated systems. Since ProQ has recently been recognized as a global posttranscriptional regulator in many bacteria, these findings provide new insights into multitiered regulatory mechanisms for the precise control of virulence factor production in bacterial pathogens.
Collapse
|
22
|
Farjad M, Clément G, Launay A, Jeridi R, Jolivet S, Citerne S, Rigault M, Soulie M, Dinant S, Fagard M. Plant nitrate supply regulates Erwinia amylovora virulence gene expression in Arabidopsis. MOLECULAR PLANT PATHOLOGY 2021; 22:1332-1346. [PMID: 34382308 PMCID: PMC8518577 DOI: 10.1111/mpp.13114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 06/26/2021] [Indexed: 05/03/2023]
Abstract
We showed previously that nitrogen (N) limitation decreases Arabidopsis resistance to Erwinia amylovora (Ea). We show that decreased resistance to bacteria in low N is correlated with lower apoplastic reactive oxygen species (ROS) accumulation and lower jasmonic acid (JA) pathway expression. Consistently, pretreatment with methyl jasmonate (Me-JA) increased the resistance of plants grown under low N. In parallel, we show that in planta titres of a nonvirulent type III secretion system (T3SS)-deficient Ea mutant were lower than those of wildtype Ea in low N, as expected, but surprisingly not in high N. This lack of difference in high N was consistent with the low expression of the T3SS-encoding hrp virulence genes by wildtype Ea in plants grown in high N compared to plants grown in low N. This suggests that expressing its virulence factors in planta could be a major limiting factor for Ea in the nonhost Arabidopsis. To test this hypothesis, we preincubated Ea in an inducing medium that triggers expression of hrp genes in vitro, prior to inoculation. This preincubation strongly enhanced Ea titres in planta, independently of the plant N status, and was correlated to a significant repression of JA-dependent genes. Finally, we identify two clusters of metabolites associated with resistance or with susceptibility to Ea. Altogether, our data showed that high susceptibility of Arabidopsis to Ea, under low N or following preincubation in hrp-inducing medium, is correlated with high expression of the Ea hrp genes in planta and low expression of the JA signalling pathway, and is correlated with the accumulation of specific metabolites.
Collapse
Affiliation(s)
- Mahsa Farjad
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Gilles Clément
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Alban Launay
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Roua Jeridi
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
- Laboratoire des Risques Liés Aux Stress EnvironnementauxFaculté des Sciences de Bizerte, Université de CarthageBizerteTunisia
| | - Sylvie Jolivet
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Sylvie Citerne
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Martine Rigault
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Marie‐Christine Soulie
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
- Sorbonne UniversitéUPMC Université Paris 06ParisFrance
| | - Sylvie Dinant
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| | - Mathilde Fagard
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersaillesFrance
| |
Collapse
|
23
|
Yuan X, McGhee GC, Slack SM, Sundin GW. A Novel Signaling Pathway Connects Thiamine Biosynthesis, Bacterial Respiration, and Production of the Exopolysaccharide Amylovoran in Erwinia amylovora. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1193-1208. [PMID: 34081536 DOI: 10.1094/mpmi-04-21-0095-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora is a plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. This bacterium colonizes host vascular tissues via the production of exopolysaccharides (EPSs) including amylovoran. It is well-established that the nearly ubiquitous plasmid pEA29 of E. amylovora is an essential virulence factor, but the underlying mechanism remains uncharacterized. Here, we demonstrated that pEA29 was required for E. amylovora to produce amylovoran and to form a biofilm, and this regulation was dependent on the thiamine biosynthesis operon thiOSGF. We then conducted carbohydrate and genetic analyses demonstrating that the thiamine-mediated effect on amylovoran production was indirect, as cells lacking thiOSGF produced an EPS that did not contain glucuronic acid, one of the key components of amylovoran, whereas the transcriptional activity and RNA levels of the amylovoran biosynthesis genes were not altered. Alternatively, addition of exogenous thiamine restored amylovoran production in the pEA29-cured strain of E. amylovora and positively impacted amylovoran production in a dose-dependent manner. Individual deletion of several chromosomal thiamine biosynthesis genes also affected amylovoran production, implying that a complete thiamine biosynthesis pathway is required for the thiamine-mediated effect on amylovoran production in E. amylovora. Finally, we determined that an imbalanced tricarboxylic acid cycle negatively affected amylovoran production, which was restored by addition of exogenous thiamine or overexpression of the thiOSGF operon. In summary, our report revealed a novel signaling pathway that impacts E. amylovora virulence in which thiamine biosynthesis enhances bacterial respiration that provides energetic requirements for the biosynthesis of EPS amylovoran.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Xiaochen Yuan
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - Gayle C McGhee
- United States Department of Agriculture, Agriculture Research Service, Horticultural Crops Research Laboratory, Corvallis, OR 97330, U.S.A
| | - Suzanne M Slack
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A
| |
Collapse
|
24
|
Piazza S, Campa M, Pompili V, Costa LD, Salvagnin U, Nekrasov V, Zipfel C, Malnoy M. The Arabidopsis pattern recognition receptor EFR enhances fire blight resistance in apple. HORTICULTURE RESEARCH 2021; 8:204. [PMID: 34465763 PMCID: PMC8408165 DOI: 10.1038/s41438-021-00639-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 05/12/2023]
Abstract
Fire blight disease, caused by the bacterium Erwinia amylovora (E. amylovora), is responsible for substantial losses in cultivated apples worldwide. An important mechanism of plant immunity is based on the recognition of conserved microbial molecules, named pathogen-associated or microbe-associated molecular patterns (PAMPs or MAMPs), through pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI). The interspecies transfer of PRRs represents a promising strategy to engineer broad-spectrum and durable disease resistance in crops. EFR, the Arabidopsis thaliana PRR for the PAMP elf18 derived from the elongation factor thermal unstable (EF-Tu) proved to be effective in improving bacterial resistance when expressed into Solanaceae and other plant species. In this study, we tested whether EFR can affect the interaction of apple with E. amylovora by its ectopic expression in the susceptible apple rootstock M.26. Stable EFR expression led to the activation of PAMP-triggered immune response in apple leaves upon treatment with supernatant of E. amylovora, as measured by the production of reactive oxygen species and the induction of known defense genes. The amount of tissue necrosis associated with E. amylovora infection was significantly reduced in the EFR transgenic rootstock compared to the wild-type. Our results show that the expression of EFR in apple rootstock may be a valuable biotechnology strategy to improve the resistance of apple to fire blight.
Collapse
Affiliation(s)
- Stefano Piazza
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy
| | - Manuela Campa
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy
- Genetics Department, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
| | - Valerio Pompili
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy
| | - Lorenza Dalla Costa
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy
| | - Umberto Salvagnin
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy
| | - Vladimir Nekrasov
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Plant Sciences Department, Rothamsted Research, Harpenden, UK
| | - Cyril Zipfel
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Institute of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Mickael Malnoy
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele a/Adige, Italy.
| |
Collapse
|
25
|
Kharadi RR, Schachterle JK, Yuan X, Castiblanco LF, Peng J, Slack SM, Zeng Q, Sundin GW. Genetic Dissection of the Erwinia amylovora Disease Cycle. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:191-212. [PMID: 33945696 DOI: 10.1146/annurev-phyto-020620-095540] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fire blight, caused by the bacterial phytopathogen Erwinia amylovora, is an economically important and mechanistically complex disease that affects apple and pear production in most geographic production hubs worldwide. We compile, assess, and present a genetic outlook on the progression of an E. amylovora infection in the host. We discuss the key aspects of type III secretion-mediated infection and systemic movement, biofilm formation in xylem, and pathogen dispersal via ooze droplets, a concentrated suspension of bacteria and exopolysaccharide components. We present an overall outlook on the genetic elements contributing to E. amylovora pathogenesis, including an exploration of the impact of floral microbiomes on E. amylovora colonization, and summarize the current knowledge of host responses to an incursion and how this response stimulates further infection and systemic spread. We hope to facilitate the identification of new, unexplored areas of research in this pathosystem that can help identify evolutionarily susceptible genetic targets to ultimately aid in the design of sustainable strategies for fire blight disease mitigation.
Collapse
Affiliation(s)
- Roshni R Kharadi
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Jeffrey K Schachterle
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
- Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, Beltsville, Maryland 20705, USA
| | - Xiaochen Yuan
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Luisa F Castiblanco
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Jingyu Peng
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Suzanne M Slack
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| | - Quan Zeng
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, USA
| | - George W Sundin
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, USA;
| |
Collapse
|
26
|
Peil A, Emeriewen OF, Khan A, Kostick S, Malnoy M. Status of fire blight resistance breeding in Malus. JOURNAL OF PLANT PATHOLOGY 2021; 103:3-12. [PMID: 0 DOI: 10.1007/s42161-020-00581-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 05/21/2020] [Indexed: 05/20/2023]
|
27
|
Yuan X, Hulin MT, Sundin GW. Effectors, chaperones, and harpins of the Type III secretion system in the fire blight pathogen Erwinia amylovora: a review. JOURNAL OF PLANT PATHOLOGY 2021; 103:25-39. [PMID: 0 DOI: 10.1007/s42161-020-00623-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/23/2020] [Indexed: 05/20/2023]
|
28
|
Emeriewen OF, Flachowsky H, Peil A. Characterization of genomic DNA sequence of the candidate gene for FB_Mfu10 associated with fire blight resistance in Malus species. BMC Res Notes 2021; 14:291. [PMID: 34315526 PMCID: PMC8314441 DOI: 10.1186/s13104-021-05709-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/20/2021] [Indexed: 11/25/2022] Open
Abstract
Objective The proposed candidate gene underlying the Malus fusca fire blight resistance locus on chromosome 10 was previously predicted to possess 880 amino acids and 8 exons. Eight base pair (8 bp) insertion/deletion in the first exon potentially distinguished resistant genotypes from susceptible ones. This study aimed at analyzing the candidate gene sequence in another set of original resistant and susceptible progeny, characterizing the sequence in a transgenic line transformed with the candidate gene under its own native promoter, as well as deciphering the potential genomic differences between this candidate gene and its homolog in the ‘Golden Delicious’ doubled haploid genome (GDDH13). Results Sequences of amplicons of part of the candidate gene amplified in two progenies that showed resistant and susceptible fire blight phenotypes, confirmed the 8 bp insertion that distinguishes susceptible and resistant progenies. The transgenic line was positive for the candidate gene sequence, confirming a successful transfer into the background of apple cultivar ‘Pinova’, and possessed the same genomic sequence as the progeny with a resistant phenotype. Sequence analysis showed that the homolog gene on GDDH13 possesses a significant 18 bp deletion in exon 1 leading to a difference of 15 amino acid from the protein sequence of the candidate gene. Supplementary Information The online version contains supplementary material available at 10.1186/s13104-021-05709-2.
Collapse
Affiliation(s)
- Ofere Francis Emeriewen
- Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research On Fruit Crops, Dresden, Germany.
| | - Henryk Flachowsky
- Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research On Fruit Crops, Dresden, Germany
| | - Andreas Peil
- Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research On Fruit Crops, Dresden, Germany
| |
Collapse
|
29
|
Thapa R, Singh J, Gutierrez B, Arro J, Khan A. Genome-wide association mapping identifies novel loci underlying fire blight resistance in apple. THE PLANT GENOME 2021; 14:e20087. [PMID: 33650322 DOI: 10.1002/tpg2.20087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/17/2020] [Indexed: 05/12/2023]
Abstract
Fire blight, caused by epiphytotic gram-negative bacteria Erwinia amylovora, is the most destructive bacterial disease of apple (Malus spp.). Genetic mechanisms of fire blight resistance have mainly been studied using traditional biparental quantitative trait loci (QTL) mapping approaches. Here, we use large-scale historic shoot and blossom fire blight data collected over multiple years and genotyping-by-sequencing (GBS) markers to identify significant marker-trait associations in a diverse set of 566 apple [Malus domestica (Suckow) Borkh.] accessions. There was large variation in fire blight resistance and susceptibility in these accessions. We identified 23 and 38 QTL significantly (p < .001) associated with shoot and blossom blight resistance, respectively. The QTL are distributed across all 17 chromosomes of apple. Four shoot blight and 19 blossom blight QTL identified in this study colocalized with previously identified QTL associated with resistance to fire blight or apple scab. Using transcriptomics data of two apple cultivars with contrasting fire blight responses, we also identified candidate genes for fire blight resistance that are differentially expressed between resistant and susceptible cultivars and located within QTL intervals for fire blight resistance. However, further experiments are needed to confirm and validate these marker-trait associations and develop diagnostic markers before use in marker-assisted breeding to develop apple cultivars with decreased fire blight susceptibility.
Collapse
Affiliation(s)
- Ranjita Thapa
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Benjamin Gutierrez
- USDA-ARS Plant Genetic Resources Unit, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY, 14456, USA
| | - Jie Arro
- USDA-ARS Plant Genetic Resources Unit, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY, 14456, USA
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| |
Collapse
|
30
|
Bénéjam J, Ravon E, Gaucher M, Brisset MN, Durel CE, Perchepied L. Acibenzolar- S-Methyl and Resistance Quantitative Trait Loci Complement Each Other to Control Apple Scab and Fire Blight. PLANT DISEASE 2021; 105:1702-1710. [PMID: 33190613 DOI: 10.1094/pdis-07-20-1439-re] [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: 06/11/2023]
Abstract
Diversifying disease control methods is a key strategy to sustainably reduce pesticides. Plant genetic resistance has long been used to create resistant varieties. Plant resistance inducers (PRI) are also considered to promote crop health, but their effectiveness is partial and can vary according to the environment and the plant genotype. We investigated the putative interaction between intrinsic (genetic) and PRI-induced resistance in apple when affected by scab and fire blight diseases. A large F1 mapping population was challenged by each disease after a pre-treatment with acibenzolar-S-methyl (ASM) and compared with the water control. Apple scab and fire blight resistance quantitative trait loci (QTLs) were detected in both conditions and compared. ASM exhibited a strong effectiveness in reducing both diseases. When combined, QTL-controlled and ASM-induced resistance acted complementarily to reduce the symptoms from 85 to 100%, depending on the disease. In our conditions, resistance QTLs were only slightly or rarely affected by ASM treatment, despite their probable implication in various stages of the resistance buildup. Implications of these results are discussed considering already known results, the underlying mechanisms, cross protection of both types of resistance against pathogen adaptation, and practical application in orchard conditions.
Collapse
Affiliation(s)
- Juliette Bénéjam
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Elisa Ravon
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Matthieu Gaucher
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | | | - Charles-Eric Durel
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Laure Perchepied
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| |
Collapse
|
31
|
Song JY, Yun YH, Kim GD, Kim SH, Lee SJ, Kim JF. Genome Analysis of Erwinia amylovora Strains Responsible for a Fire Blight Outbreak in Korea. PLANT DISEASE 2021; 105:1143-1152. [PMID: 32931384 DOI: 10.1094/pdis-06-20-1329-re] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Erwinia amylovora is a plant-pathogenic bacterium that causes fire blight disease in Rosaceae plants. Since fire blight is highly contagious and results in serious losses once introduced, it is regulated as a quarantine disease. Recently, for the first time in East Asia, fire blight emerged in Korea with strains of E. amylovora being isolated from lesions of infected trees. Five of those strains were selected and subjected to whole-genome shotgun sequencing. Each strain had two circular replicons, a 3.8-Mb chromosome and a 28-kb plasmid. The genome sequences were compared with those of other E. amylovora strains isolated from different hosts or geographical regions. Genome synteny was analyzed and sequence variations including nucleotide substitutions, inversions, insertions, and deletions were detected. Analysis of the population genomic structure revealed that the five strains form a distinct structural group. Phylogenomic analysis was performed to infer the evolutionary relationships among E. amylovora strains, which indicated that the Korean isolates, all descended from a common ancestor, are closely related to a lineage of North American strains. These results provide useful information for understanding the genomic dynamics of E. amylovora strains including those in Korea, developing genetic markers for surveillance of the pathogen or diagnosis of the disease, and eventually developing measures to eradicate it.
Collapse
Affiliation(s)
- Ju Yeon Song
- Department of Systems Biology, Division of Life Sciences, and Institute for Life Science and Biotechnology, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Yeo Hong Yun
- Department of Microbiology and Institute for Biodiversity, Dankook University, Dongnam-gu, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Gi-Don Kim
- Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Seong Hwan Kim
- Department of Microbiology and Institute for Biodiversity, Dankook University, Dongnam-gu, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Seong-Jin Lee
- Animal and Plant Quarantine Agency, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Jihyun F Kim
- Department of Systems Biology, Division of Life Sciences, and Institute for Life Science and Biotechnology, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
- Strategic Initiative for Microbiomes in Agriculture and Food, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
| |
Collapse
|
32
|
Peng J, Schachterle JK, Sundin GW. Orchestration of virulence factor expression and modulation of biofilm dispersal in Erwinia amylovora through activation of the Hfq-dependent small RNA RprA. MOLECULAR PLANT PATHOLOGY 2021; 22:255-270. [PMID: 33314618 PMCID: PMC7814967 DOI: 10.1111/mpp.13024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora is the causative agent of the devastating disease fire blight of pome fruit trees. After infection of host plant leaves at apple shoot tips, E. amylovora cells form biofilms in xylem vessels, restrict water flow, and cause wilting symptoms. Although E. amylovora is well known to be able to cause systemic infection, how biofilm cells of E. amylovora transit from the sessile mode of growth in xylem to the planktonic mode of growth in cortical parenchyma remains unknown. Increasing evidence has suggested the important modulatory roles of Hfq-dependent small RNAs (sRNAs) in the pathogenesis of E. amylovora. Here, we demonstrate that the sRNA RprA acts as a positive regulator of amylovoran exopolysaccharide production, the type III secretion system (T3SS), and flagellar-dependent motility, and as a negative regulator of levansucrase activity and cellulose production. We also show that RprA affects the promoter activity of multiple virulence factor genes and regulates hrpS, a critical T3SS regulator, at the posttranscriptional level. We determined that rprA expression can be activated by the Rcs phosphorelay, and that expression is active during T3SS-mediated host infection in an immature pear fruit infection model. We further showed that overexpression of rprA activated the in vitro dispersal of E. amylovora cells from biofilms. Thus, our investigation of the varied role of RprA in affecting E. amylovora virulence provides important insights into the functions of this sRNA in biofilm control and systemic infection.
Collapse
Affiliation(s)
- Jingyu Peng
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Jeffrey K. Schachterle
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
- Present address:
US National Arboretum – Floral and Nursery Plants Research UnitUSDA‐ARSBeltsvilleMarylandUSA
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| |
Collapse
|
33
|
Activation of metabolic and stress responses during subtoxic expression of the type I toxin hok in Erwinia amylovora. BMC Genomics 2021; 22:74. [PMID: 33482720 PMCID: PMC7821729 DOI: 10.1186/s12864-021-07376-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/08/2021] [Indexed: 11/15/2022] Open
Abstract
Background Toxin-antitoxin (TA) systems, abundant in prokaryotes, are composed of a toxin gene and its cognate antitoxin. Several toxins are implied to affect the physiological state and stress tolerance of bacteria in a population. We previously identified a chromosomally encoded hok-sok type I TA system in Erwinia amylovora, the causative agent of fire blight disease on pome fruit trees. A high-level induction of the hok gene was lethal to E. amylovora cells through unknown mechanisms. The molecular targets or regulatory roles of Hok were unknown. Results Here, we examined the physiological and transcriptomic changes of Erwinia amylovora cells expressing hok at subtoxic levels that were confirmed to confer no cell death, and at toxic levels that resulted in killing of cells. In both conditions, hok caused membrane rupture and collapse of the proton motive force in a subpopulation of E. amylovora cells. We demonstrated that induction of hok resulted in upregulation of ATP biosynthesis genes, and caused leakage of ATP from cells only at toxic levels. We showed that overexpression of the phage shock protein gene pspA largely reversed the cell death phenotype caused by high levels of hok induction. We also showed that induction of hok at a subtoxic level rendered a greater proportion of stationary phase E. amylovora cells tolerant to the antibiotic streptomycin. Conclusions We characterized the molecular mechanism of toxicity by high-level of hok induction and demonstrated that low-level expression of hok primes the stress responses of E. amylovora against further membrane and antibiotic stressors. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07376-w.
Collapse
|
34
|
Singh J, Cobb-Smith D, Higgins E, Khan A. Comparative evaluation of lateral flow immunoassays, LAMP, and quantitative PCR for diagnosis of fire blight in apple orchards. JOURNAL OF PLANT PATHOLOGY : AN INTERNATIONAL JOURNAL OF THE ITALIAN PHYTOPATHOLOGICAL SOCIETY 2021; 103:131-142. [PMID: 32904534 PMCID: PMC7456764 DOI: 10.1007/s42161-020-00644-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 08/26/2020] [Indexed: 05/11/2023]
Abstract
Fire blight remains a serious threat to commercial apple production in the USA and worldwide. Other diseases and spray damage can result in fire blight-like symptoms that can lead to misdiagnosis and affect disease management strategies. Accurate and timely detection of the fire blight pathogen, Erwinia amylovora, is extremely important to deploy appropriate and timely measures to reduce fire blight epidemics in commercial apple orchards. We tested two commercial lateral flow immunoassays (AgriStrip®, and Pocket Diagnostics kit), Loop mediated isothermal amplification (LAMP), and quantitative PCR (qPCR) to diagnose E. amylovora infected samples in lab and field settings. The AgriStrip® and Pocket Diagnostics kits were able to detect actively growing bacteria up to ×106 cfu/ml bacterial concentration. Pocket Diagnostics kit had less specificity and showed positive tests for E. pyrifolia in addition to E. amylovora. The LAMP assay showed high specificity for E. amylovora and was able to detect up to ×103 cfu/ml bacterial concentrations. The qPCR assay was also able to detect bacterial cells up to ×10-3 cfu/ml bacterial concentration with highly specific E. amylovora detection. Grower surveys and comparative cost-benefit analysis indicated that immunoassay kits are less expensive, easier to use, and require less technical expertise for on-site fire blight diagnosis than LAMP and qPCR. However, the choice of a specific diagnostic assay depends on the time, sensitivity, and specificity required for the detection of fire blight and its management.
Collapse
Affiliation(s)
- Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
| | - Della Cobb-Smith
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
| | - Elizabeth Higgins
- Eastern NY Commercial Horticulture Program, Cornell Cooperative Extension at Hudson Valley Research Lab, Highland, NY 12528 USA
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
| |
Collapse
|
35
|
Maglangit F, Yu Y, Deng H. Bacterial pathogens: threat or treat (a review on bioactive natural products from bacterial pathogens). Nat Prod Rep 2021; 38:782-821. [PMID: 33119013 DOI: 10.1039/d0np00061b] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Covering: up to the second quarter of 2020 Threat or treat? While pathogenic bacteria pose significant threats, they also represent a huge reservoir of potential pharmaceuticals to treat various diseases. The alarming antimicrobial resistance crisis and the dwindling clinical pipeline urgently call for the discovery and development of new antibiotics. Pathogenic bacteria have an enormous potential for natural products drug discovery, yet they remained untapped and understudied. Herein, we review the specialised metabolites isolated from entomopathogenic, phytopathogenic, and human pathogenic bacteria with antibacterial and antifungal activities, highlighting those currently in pre-clinical trials or with potential for drug development. Selected unusual biosynthetic pathways, the key roles they play (where known) in various ecological niches are described. We also provide an overview of the mode of action (molecular target), activity, and minimum inhibitory concentration (MIC) towards bacteria and fungi. The exploitation of pathogenic bacteria as a rich source of antimicrobials, combined with the recent advances in genomics and natural products research methodology, could pave the way for a new golden age of antibiotic discovery. This review should serve as a compendium to communities of medicinal chemists, organic chemists, natural product chemists, biochemists, clinical researchers, and many others interested in the subject.
Collapse
Affiliation(s)
- Fleurdeliz Maglangit
- Department of Biology and Environmental Science, College of Science, University of the Philippines Cebu, Lahug, Cebu City, 6000, Philippines. and Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, UK.
| | - Yi Yu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE), Hubei Province Engineering and Technology Research Centre for Fluorinated Pharmaceuticals, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China.
| | - Hai Deng
- Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, UK.
| |
Collapse
|
36
|
Emeriewen OF, Richter K, Flachowsky H, Malnoy M, Peil A. Genetic Analysis and Fine Mapping of the Fire Blight Resistance Locus of Malus ×arnoldiana on Linkage Group 12 Reveal First Candidate Genes. FRONTIERS IN PLANT SCIENCE 2021; 12:667133. [PMID: 33959143 PMCID: PMC8093435 DOI: 10.3389/fpls.2021.667133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/24/2021] [Indexed: 05/03/2023]
Abstract
Malus ×arnoldiana accession MAL0004 has been found to be resistant to moderately and highly virulent strains of the fire blight causal pathogen - the Gram-negative bacterium, Erwinia amylovora. Genetic analyses with an F1 segregating population derived from crossing the highly susceptible apple cultivar 'Idared' and MAL0004 led to the detection and mapping of the fire blight resistance locus of M. ×arnoldiana to linkage group (LG)12 (FB_Mar12). FB_Mar12 mapped at the distal end of LG12 below the apple SSR Hi07f01 in an interval of approximately 6 cM (Centimorgan), where both the fire blight resistance loci of M. floribunda 821 and 'Evereste' were located. We fine mapped the region containing FB_Mar12 using 892 progenies. Mining of the region of interest (ROI) on the 'Golden Delicious' doubled haploid genome (GDDH13) identified the presence of 2.3 Mb (megabases) in the homologous region. Of 40 primer pairs designed within this region, 20 were polymorphic and nine were mapped, leading to the identification of 24 significant recombinant individuals whose phenotypes were informative in determining the precise position of the locus within a 0.57 cM interval. Analyses of tightly linked marker sequences on the M. baccata draft genome revealed scaffolds of interest putatively harboring the resistance loci of M. ×arnoldiana, a hybrid between M. baccata and M. floribunda. Open reading frame (ORF) analyses led to the prediction of first fire blight resistance candidate genes with serine/threonine kinase and leucine-rich repeat domains, including homologs of previously identified 'Evereste' candidate genes. We discuss the implications of these results on breeding for resistance to fire blight.
Collapse
Affiliation(s)
- Ofere Francis Emeriewen
- Julius Kühn Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Dresden, Germany
- Ofere Francis Emeriewen,
| | - Klaus Richter
- Julius Kühn Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Quedlinburg, Germany
| | - Henryk Flachowsky
- Julius Kühn Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Dresden, Germany
| | - Mickael Malnoy
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all’Adige, Italy
| | - Andreas Peil
- Julius Kühn Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Dresden, Germany
- *Correspondence: Andreas Peil,
| |
Collapse
|
37
|
Tremblay O, Thow Z, Merrill AR. Several New Putative Bacterial ADP-Ribosyltransferase Toxins Are Revealed from In Silico Data Mining, Including the Novel Toxin Vorin, Encoded by the Fire Blight Pathogen Erwinia amylovora. Toxins (Basel) 2020; 12:E792. [PMID: 33322547 PMCID: PMC7764402 DOI: 10.3390/toxins12120792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/28/2020] [Accepted: 12/10/2020] [Indexed: 12/31/2022] Open
Abstract
Mono-ADP-ribosyltransferase (mART) toxins are secreted by several pathogenic bacteria that disrupt vital host cell processes in deadly diseases like cholera and whooping cough. In the last two decades, the discovery of mART toxins has helped uncover the mechanisms of disease employed by pathogens impacting agriculture, aquaculture, and human health. Due to the current abundance of mARTs in bacterial genomes, and an unprecedented availability of genomic sequence data, mART toxins are amenable to discovery using an in silico strategy involving a series of sequence pattern filters and structural predictions. In this work, a bioinformatics approach was used to discover six bacterial mART sequences, one of which was a functional mART toxin encoded by the plant pathogen, Erwinia amylovora, called Vorin. Using a yeast growth-deficiency assay, we show that wild-type Vorin inhibited yeast cell growth, while catalytic variants reversed the growth-defective phenotype. Quantitative mass spectrometry analysis revealed that Vorin may cause eukaryotic host cell death by suppressing the initiation of autophagic processes. The genomic neighbourhood of Vorin indicated that it is a Type-VI-secreted effector, and co-expression experiments showed that Vorin is neutralized by binding of a cognate immunity protein, VorinI. We demonstrate that Vorin may also act as an antibacterial effector, since bacterial expression of Vorin was not achieved in the absence of VorinI. Vorin is the newest member of the mART family; further characterization of the Vorin/VorinI complex may help refine inhibitor design for mART toxins from other deadly pathogens.
Collapse
Affiliation(s)
| | | | - A. Rod Merrill
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (O.T.); (Z.T.)
| |
Collapse
|
38
|
Yuan X, Yu M, Yang CH. Innovation and Application of the Type III Secretion System Inhibitors in Plant Pathogenic Bacteria. Microorganisms 2020; 8:microorganisms8121956. [PMID: 33317075 PMCID: PMC7764658 DOI: 10.3390/microorganisms8121956] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022] Open
Abstract
Many Gram-negative pathogenic bacteria rely on a functional type III secretion system (T3SS), which injects multiple effector proteins into eukaryotic host cells, for their pathogenicity. Genetic studies conducted in different host-microbe pathosystems often revealed a sophisticated regulatory mechanism of their T3SSs, suggesting that the expression of T3SS is tightly controlled and constantly monitored by bacteria in response to the ever-changing host environment. Therefore, it is critical to understand the regulation of T3SS in pathogenic bacteria for successful disease management. This review focuses on a model plant pathogen, Dickeyadadantii, and summarizes the current knowledge of its T3SS regulation. We highlight the roles of several T3SS regulators that were recently discovered, including the transcriptional regulators: FlhDC, RpoS, and SlyA; the post-transcriptional regulators: PNPase, Hfq with its dependent sRNA ArcZ, and the RsmA/B system; and the bacterial second messenger cyclic-di-GMP (c-di-GMP). Homologs of these regulatory components have also been characterized in almost all major bacterial plant pathogens like Erwiniaamylovora, Pseudomonassyringae, Pectobacterium spp., Xanthomonas spp., and Ralstonia spp. The second half of this review shifts focus to an in-depth discussion of the innovation and development of T3SS inhibitors, small molecules that inhibit T3SSs, in the field of plant pathology. This includes T3SS inhibitors that are derived from plant phenolic compounds, plant coumarins, and salicylidene acylhydrazides. We also discuss their modes of action in bacteria and application for controlling plant diseases.
Collapse
Affiliation(s)
- Xiaochen Yuan
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA;
| | - Manda Yu
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
- Correspondence: (M.Y.); (C.-H.Y.)
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
- Correspondence: (M.Y.); (C.-H.Y.)
| |
Collapse
|
39
|
Dagher F, Olishevska S, Philion V, Zheng J, Déziel E. Development of a novel biological control agent targeting the phytopathogen Erwinia amylovora. Heliyon 2020; 6:e05222. [PMID: 33102848 PMCID: PMC7578203 DOI: 10.1016/j.heliyon.2020.e05222] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/18/2020] [Accepted: 10/08/2020] [Indexed: 10/27/2022] Open
Abstract
Antibiotics are used extensively to control animal, plant, and human pathogens. They are sprayed on apple and pear orchards to control the bacterium Erwinia amylovora, the causative agent of fire blight. This phytopathogen is developing antibiotic resistance and alternatives either have less efficacy, are phytotoxic, or more management intensive. The objective of our study was to develop an effective biological control agent colonizing the host plant and competing with Erwinia amylovora. It must not be phytotoxic, have a wide spectrum of activity, and be unlikely to induce resistance in the pathogen. To this end, several bacterial isolates from various environmental samples were screened to identify suitable candidates that are antagonistic to E. amylovora. We sampled bacteria from the flowers, leaves, and soil from apple and pear orchards from the springtime bloom period until the summer. The most effective bacteria, including isolates of Pseudomonas poae, Paenibacillus polymyxa, Bacillus amyloliquefaciens and Pantoea agglomerans, were tested in vitro and in vivo and formulated into products containing both the live strains and their metabolites that were stable for at least 9 months. Trees treated with the product based on P. agglomerans NY60 had significantly less fire blight than the untreated control and were statistically not different from streptomycin-treated control trees. With P. agglomerans NY60, fire blight never extended beyond the central vein of the inoculated leaf. The fire blight median disease severity score, 10 days after inoculation, was up to 70% less severe on trees treated with P. agglomerans NY60 as compared to untreated controls.
Collapse
Affiliation(s)
- Fadi Dagher
- INRS-Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada
| | | | | | - Jie Zheng
- US Food and Drug Administration Regulatory Science Center for Food Safety and Applied Nutrition, 5100, Paint Branch Parkway, College Park, MD, USA
| | - Eric Déziel
- INRS-Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada
| |
Collapse
|
40
|
Tegtmeier R, Pompili V, Singh J, Micheletti D, Silva KJP, Malnoy M, Khan A. Candidate gene mapping identifies genomic variations in the fire blight susceptibility genes HIPM and DIPM across the Malus germplasm. Sci Rep 2020; 10:16317. [PMID: 33004843 PMCID: PMC7529791 DOI: 10.1038/s41598-020-73284-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 09/15/2020] [Indexed: 02/07/2023] Open
Abstract
Development of apple (Malus domestica) cultivars resistant to fire blight, a devastating bacterial disease caused by Erwinia amylovora, is a priority for apple breeding programs. Towards this goal, the inactivation of members of the HIPM and DIPM gene families with a role in fire blight susceptibility (S genes) can help achieve sustainable tolerance. We have investigated the genomic diversity of HIPM and DIPM genes in Malus germplasm collections and used a candidate gene-based association mapping approach to identify SNPs (single nucleotide polymorphisms) with significant associations to fire blight susceptibility. A total of 87 unique SNP variants were identified in HIPM and DIPM genes across 93 Malus accessions. Thirty SNPs showed significant associations (p < 0.05) with fire blight susceptibility traits, while two of these SNPs showed highly significant (p < 0.001) associations across two different years. This research has provided knowledge about genetic diversity in fire blight S genes in diverse apple accessions and identified candidate HIPM and DIPM alleles that could be used to develop apple cultivars with decreased fire blight susceptibility via marker-assisted breeding or biotechnological approaches.
Collapse
Affiliation(s)
- Richard Tegtmeier
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Valerio Pompili
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Diego Micheletti
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | | | - Mickael Malnoy
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy.
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA.
| |
Collapse
|
41
|
Zhang WB, Yan HL, Zhu ZC, Zhang C, Du PX, Zhao WJ, Li WM. Genome-wide identification of the Sec-dependent secretory protease genes in Erwinia amylovora and analysis of their expression during infection of immature pear fruit. J Zhejiang Univ Sci B 2020; 21:716-726. [PMID: 32893528 DOI: 10.1631/jzus.b2000281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The general secretory (Sec) pathway represents a common mechanism by which bacteria secrete proteins, including virulence factors, into the extracytoplasmic milieu. However, there is little information about this system, as well as its associated secretory proteins, in relation to the fire blight pathogen Erwinia amylovora. In this study, data mining revealed that E. amylovora harbors all of the essential components of the Sec system. Based on this information, we identified putative Sec-dependent secretory proteases in E. amylovora on a genome-wide scale. Using the programs SignalP, LipoP, and Phobius, a total of 15 putative proteases were predicted to contain the N-terminal signal peptides (SPs) that might link them to the Sec-dependent pathway. The activities of the predicted SPs were further validated using an Escherichia coli-based alkaline phosphatase (PhoA) gene fusion system that confirmed their extracytoplasmic property. Transcriptional analyses showed that the expression of 11 of the 15 extracytoplasmic protease genes increased significantly when E. amylovora was used to inoculate immature pears, suggesting their potential roles in plant infection. The results of this study support the suggestion that E. amylovora might employ the Sec system to secrete a suite of proteases to enable successful infection of plants, and shed new light on the interaction of E. amylovora with host plants.
Collapse
Affiliation(s)
- Wang-Bin Zhang
- College of Plant Science, Tarim University, Alar 843300, China.,Southern Xinjiang Key Laboratory of Integrated Pest Management, Tarim University, Alar 843300, China
| | - Hai-Lin Yan
- College of Plant Science, Tarim University, Alar 843300, China.,Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zong-Cai Zhu
- College of Plant Science, Tarim University, Alar 843300, China.,Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Chao Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Pei-Xiu Du
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wen-Jun Zhao
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Wei-Min Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| |
Collapse
|
42
|
Zurn JD, Norelli JL, Montanari S, Bell R, Bassil NV. Dissecting Genetic Resistance to Fire Blight in Three Pear Populations. PHYTOPATHOLOGY 2020; 110:1305-1311. [PMID: 32175827 DOI: 10.1094/phyto-02-20-0051-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fire blight, caused by the bacterial pathogen Erwinia amylovora, is a persistent problem for pear (Pyrus spp.) growers in the United States. Growing resistant cultivars is one of the best options for managing fire blight. The cultivars Potomac and Old Home and the selection NJA2R59T69 display resistance to fire blight. As such, three mapping populations (El Dorado × Potomac, Old Home × Bartlett, and NJA2R59T69 × Bartlett) were developed to identify genomic regions associated with resistance to fire blight. Progeny were phenotyped during 2017 and 2018 by inoculating multiple actively growing shoots of field-grown seedling trees with E. amylovora isolate E153n via the cut-leaf method. Genotyping was conducted using the recently developed Axiom Pear 70 K Genotyping Array and chromosomal linkage groups were created for each population. An integrated two-way pseudo-testcross approach was used to map quantitative trait loci (QTLs). Resistance QTLs were identified on chromosome 2 for each population. The QTLs identified in the El Dorado × Potomac and Old Home × Bartlett populations are in the same region as QTLs that were previously identified in Harrow Sweet and Moonglow. The QTL in NJA2R59T69 mapped proximally to the previously identified QTLs and originated from an unknown Asian or occidental source. Future research will focus on further characterizing the resistance regions and developing tools for DNA-informed breeding.
Collapse
Affiliation(s)
- Jason D Zurn
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS) National Clonal Germplasm Repository, Corvallis, OR, U.S.A
| | - John L Norelli
- USDA-ARS Appalachian Fruit Research Laboratory, Kearneysville, WV, U.S.A
| | - Sara Montanari
- Department of Plant Sciences, University of California Davis, Davis, CA, U.S.A
| | - Richard Bell
- USDA-ARS Appalachian Fruit Research Laboratory, Kearneysville, WV, U.S.A
| | - Nahla V Bassil
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS) National Clonal Germplasm Repository, Corvallis, OR, U.S.A
| |
Collapse
|
43
|
Verly C, Djoman ACR, Rigault M, Giraud F, Rajjou L, Saint-Macary ME, Dellagi A. Plant Defense Stimulator Mediated Defense Activation Is Affected by Nitrate Fertilization and Developmental Stage in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2020; 11:583. [PMID: 32528493 PMCID: PMC7264385 DOI: 10.3389/fpls.2020.00583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/17/2020] [Indexed: 05/20/2023]
Abstract
Plant defense stimulators, used in crop protection, are an attractive option to reduce the use of conventional crop protection products and optimize biocontrol strategies. These products are able to activate plant defenses and thus limit infection by pathogens. However, the effectiveness of these plant defense stimulators remains erratic and is potentially dependent on many agronomic and environmental parameters still unknown or poorly controlled. The developmental stage of the plant as well as its fertilization, and essentially nitrogen nutrition, play major roles in defense establishment in the presence of pathogens or plant defense stimulators. The major nitrogen source used by plants is nitrate. In this study, we investigated the impact of Arabidopsis thaliana plant developmental stage and nitrate nutrition on its capacity to mount immune reactions in response to two plant defense stimulators triggering two major defense pathways, the salicylic acid and the jasmonic acid pathways. We show that optimal nitrate nutrition is needed for effective defense activation and protection against the pathogenic bacteria Dickeya dadantii and Pseudomonas syringae pv. tomato. Using an npr1 defense signaling mutant, we showed that nitrate dependent protection against D. dadantii requires a functional NPR1 gene. Our results indicate that the efficacy of plant defense stimulators is strongly affected by nitrate nutrition and the developmental stage. The nitrate dependent efficacy of plant defense stimulators is not only due to a metabolic effect but also invloves NPR1 mediated defense signaling. Plant defense stimulators may have opposite effects on plant resistance to a pathogen. Together, our results indicate that agronomic use of plant defense stimulators must be optimized according to nitrate fertilization and developmental stage.
Collapse
Affiliation(s)
- Camille Verly
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- Staphyt-Service L&G/BIOTEAM, Martillac, France
| | - Atsin Claude Roméo Djoman
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- Staphyt-Service L&G/BIOTEAM, Martillac, France
| | - Martine Rigault
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | | | - Loïc Rajjou
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | | | - Alia Dellagi
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
- *Correspondence: Alia Dellagi,
| |
Collapse
|
44
|
Kurilla A, Toth T, Dorgai L, Darula Z, Lakatos T, Silhavy D, Kerenyi Z, Dallmann G. Nectar- and stigma exudate-specific expression of an acidic chitinase could partially protect certain apple cultivars against fire blight disease. PLANTA 2019; 251:20. [PMID: 31781986 DOI: 10.1007/s00425-019-03303-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
MAIN CONCLUSION Certain apple cultivars accumulate to high levels in their nectar and stigma exudate an acidic chitinase III protein that can protect against pathogens including fire blight disease causing Erwinia amylovora. To prevent microbial infections, flower nectars and stigma exudates contain various antimicrobial compounds. Erwinia amylovora, the causing bacterium of the devastating fire blight apple disease, is the model pathogen that multiplies in flower secretions and infects through the nectaries. Although Erwinia-resistant apples are not available, certain cultivars are tolerant. It was reported that in flower infection assay, the 'Freedom' cultivar was Erwinia tolerant, while the 'Jonagold' cultivar was susceptible. We hypothesized that differences in the nectar protein compositions lead to different susceptibility. Indeed, we found that an acidic chitinase III protein (Machi3-1) selectively accumulates to very high levels in the nectar and the stigma exudate of the 'Freedom' cultivar. We show that three different Machi3-1 alleles exist in apple cultivars and that only the 5B-Machi3-1 allele expresses the Machi3-1 protein in the nectar and the stigma exudate. We demonstrate that the 5B-Machi3-1 allele was introgressed from the Malus floribunda 821 clone into different apple cultivars including the 'Freedom'. Our data suggest that MYB-binding site containing repeats of the 5B-Machi3-1 promoter is responsible for the strong nectar- and stigma exudate-specific expression. As we found that in vitro, the Machi3-1 protein impairs growth and biofilm formation of Erwinia at physiological concentration, we propose that the Machi3-1 protein could partially protect 5B-Machi3-1 allele containing cultivars against Erwinia by inhibiting the multiplication and biofilm formation of the pathogen in the stigma exudate and in the nectar.
Collapse
Affiliation(s)
- Anita Kurilla
- Agricultural Biotechnology Institute, Szent-Györgyi 4, Gödöllő, 2100, Hungary
| | - Timea Toth
- Research Institute for Fruitgrowing and Ornamentals, Park 2, Budapest, 1223, Hungary
| | | | - Zsuzsanna Darula
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt 62, Szeged, 6726, Hungary
| | - Tamas Lakatos
- Research Institute for Fruitgrowing and Ornamentals, Park 2, Budapest, 1223, Hungary
| | - Daniel Silhavy
- Agricultural Biotechnology Institute, Szent-Györgyi 4, Gödöllő, 2100, Hungary.
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt 62, Szeged, 6726, Hungary.
| | - Zoltan Kerenyi
- Agricultural Biotechnology Institute, Szent-Györgyi 4, Gödöllő, 2100, Hungary
- MTKI, Lucsony 24, Mosonmagyaróvár, 9200, Hungary
| | - Geza Dallmann
- Agricultural Biotechnology Institute, Szent-Györgyi 4, Gödöllő, 2100, Hungary
| |
Collapse
|
45
|
Singh J, Khan A. Distinct patterns of natural selection determine sub-population structure in the fire blight pathogen, Erwinia amylovora. Sci Rep 2019; 9:14017. [PMID: 31570749 PMCID: PMC6768868 DOI: 10.1038/s41598-019-50589-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/16/2019] [Indexed: 11/09/2022] Open
Abstract
The fire blight pathogen, Erwinia amylovora (EA), causes significant economic losses in rosaceae fruit crops. Recent genome sequencing efforts have explored genetic variation, population structure, and virulence levels in EA strains. However, the genomic aspects of population bottlenecks and selection pressure from geographical isolation, host range, and management practices are yet unexplored. We conducted a comprehensive analysis of whole genome sequences of 41 strains to study genetic diversity, population structure, and the nature of selection affecting sub-population differentiation in EA. We detected 72,741 SNPs and 2,500 Indels, representing about six-fold more diversity than previous reports. Moreover, nonsynonymous substitutions were identified across the effector regions, suggesting a role in defining virulence of specific strains. EA plasmids had more diversity than the chromosome sequence. Population structure analysis identified three distinct sub-groups in EA strains, with North American strains displaying highest genetic diversity. A five kilobase genomic window scan showed differences in genomic diversity and selection pressure between these three sub-groups. This analysis also highlighted the role of purifying and balancing selection in shaping EA genome structure. Our analysis provides novel insights into the genomic diversity and selection forces accompanying EA population differentiation.
Collapse
Affiliation(s)
- Jugpreet Singh
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA.
| |
Collapse
|
46
|
Chromosomally Encoded hok-sok Toxin-Antitoxin System in the Fire Blight Pathogen Erwinia amylovora: Identification and Functional Characterization. Appl Environ Microbiol 2019; 85:AEM.00724-19. [PMID: 31101613 DOI: 10.1128/aem.00724-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/08/2019] [Indexed: 12/28/2022] Open
Abstract
Toxin-antitoxin (TA) systems are genetic elements composed of a protein toxin and a counteracting antitoxin that is either a noncoding RNA or protein. In type I TA systems, the antitoxin is a noncoding small RNA (sRNA) that base pairs with the cognate toxin mRNA interfering with its translation. Although type I TA systems have been extensively studied in Escherichia coli and a few human or animal bacterial pathogens, they have not been characterized in plant-pathogenic bacteria. In this study, we characterized a chromosomal locus in the plant pathogen Erwinia amylovora Ea1189 that is homologous to the hok-sok type I TA system previously identified in the Enterobacteriaceae-restricted plasmid R1. Phylogenetic analysis indicated that the chromosomal location of the hok-sok locus is, thus far, unique to E. amylovora We demonstrated that ectopic overexpression of hok is highly toxic to E. amylovora and that the sRNA sok reversed the toxicity of hok through mok, a reading frame presumably translationally coupled with hok We also identified the region that is essential for maintenance of the main toxicity of Hok. Through a hok-sok deletion mutant (Ea1189Δhok-sok), we determined the contribution of the hok-sok locus to cellular growth, micromorphology, and catalase activity. Combined, our findings indicate that the hok-sok TA system, besides being potentially self-toxic, provides fitness advantages to E. amylovora IMPORTANCE Bacterial toxin-antitoxin systems have received great attention because of their potential as targets for antimicrobial development and as tools for biotechnology. Erwinia amylovora, the causal agent of fire blight disease on pome fruit trees, is a major plant-pathogenic bacterium. In this study, we identified and functionally characterized a unique chromosomally encoded hok-sok toxin-antitoxin system in E. amylovora that resembles the plasmid-encoded copies of this system in other Enterobacteriaceae This study of a type I toxin-antitoxin system in a plant-pathogenic bacterium provides the basis to further understand the involvement of toxin-antitoxin systems during infection by a plant-pathogenic bacterium. The new linkage between the hok-sok toxin-antitoxin system and the catalase-mediated oxidative stress response leads to additional considerations of targeting this system for antimicrobial development.
Collapse
|
47
|
Silva KJP, Singh J, Bednarek R, Fei Z, Khan A. Differential gene regulatory pathways and co-expression networks associated with fire blight infection in apple ( Malus × domestica). HORTICULTURE RESEARCH 2019; 6:35. [PMID: 30962933 PMCID: PMC6441656 DOI: 10.1038/s41438-019-0120-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 11/06/2018] [Accepted: 12/30/2018] [Indexed: 05/25/2023]
Abstract
Apple cultivars with durable resistance are needed for sustainable management of fire blight, the most destructive bacterial disease of apples. Although studies have identified genetic resistance to fire blight in both wild species and cultivated apples, more research is needed to understand the molecular mechanisms underlying host-pathogen interaction and differential genotypic responses to fire blight infection. We have analyzed phenotypic and transcriptional responses of 'Empire' and 'Gala' apple cultivars to fire blight by infecting them with a highly aggressive E. amylovora strain. Disease progress, based on the percentage of visual shoot necrosis, started showing significant (p < 0.001) differences between 'Empire' and 'Gala' 4 days after infection (dai). 'Empire' seems to slow down bacterial progress more rapidly after this point. We further compared transcriptome profiles of 'Empire' and 'Gala' at three different time points after fire blight infection. More genes showed differential expression in 'Gala' at earlier stages, but the number of differentially expressed genes increased in 'Empire' at 3 dai. Functional classes related to defense, cell cycle, response to stress, and biotic stress were identified and a few co-expression gene networks showed particular enrichment for plant defense and abiotic stress response genes. Several of these genes also co-localized in previously identified quantitative trait locus regions for fire blight resistance on linkage groups 7 and 12, and can serve as functional candidates for future research. These results highlight different molecular mechanisms for pathogen perception and control in two apple cultivars and will contribute toward better understanding of E. amylovora-Malus pathosystem.
Collapse
Affiliation(s)
| | - Jugpreet Singh
- 1Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
| | - Ryland Bednarek
- 1Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
- 2Boyce Thompson Institute, Cornell University, Ithaca, NY 14853 USA
| | - Zhangjun Fei
- 2Boyce Thompson Institute, Cornell University, Ithaca, NY 14853 USA
| | - Awais Khan
- 1Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456 USA
| |
Collapse
|
48
|
Schachterle JK, Zeng Q, Sundin GW. Three Hfq-dependent small RNAs regulate flagellar motility in the fire blight pathogen Erwinia amylovora. Mol Microbiol 2019; 111:1476-1492. [PMID: 30821016 DOI: 10.1111/mmi.14232] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2019] [Indexed: 12/13/2022]
Abstract
Erwinia amylovora, the causative agent of fire blight disease of apple and pear trees, causes disease on flowers by invading natural openings at the base of the floral cup. To reach these openings, the bacteria use flagellar motility to swim from stigma tips to the hypanthium and through nectar. We have previously shown that the Hfq-dependent sRNAs ArcZ, OmrAB and RmaA regulate swimming motility in E. amylovora. Here, we tested these three sRNAs to determine at what regulatory level they exert their effects and to what extent they can complement each other. We found that ArcZ and OmrAB repress the flagellar master regulator flhD post-transcriptionally. We also found that ArcZ and RmaA positively regulate flhD at the transcriptional level. The role of ArcZ as an activator of flagellar motility appears to be unique to E. amylovora and may have recently evolved. Our results suggest that the Hfq-dependent sRNAs ArcZ, OmrAB and RmaA play an integral role in regulation of flagellar motility by acting primarily on the master regulator, FlhD, but also through additional factors.
Collapse
Affiliation(s)
- Jeffrey K Schachterle
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Quan Zeng
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, USA.,Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
49
|
Pantocin A, a peptide-derived antibiotic involved in biological control by plant-associated Pantoea species. Arch Microbiol 2019; 201:713-722. [PMID: 30868174 DOI: 10.1007/s00203-019-01647-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/07/2019] [Accepted: 03/07/2019] [Indexed: 10/27/2022]
Abstract
The genus Pantoea contains a broad range of plant-associated bacteria, including some economically important plant pathogens as well as some beneficial members effective as biological control agents of plant pathogens. The most well-characterized representatives of biological control agents from this genus generally produce one or more antimicrobial compounds adding to biocontrol efficacy. Some Pantoea species evaluated as biocontrol agents for fire blight disease of apple and pear produce a histidine-reversible antibiotic. Three commonly studied histidine-reversible antibiotics produced by Pantoea spp. are herbicolin O, MccEh252, and pantocin A. Pantocin A is a novel ribosomally encoded and post-translationally modified peptide natural product. Here, we review the current knowledge on the chemistry, genetics, biosynthesis, and incidence and environmental relevance of pantocin A and related histidine-reversible antibiotics produced by Pantoea.
Collapse
|
50
|
Polsinelli I, Borruso L, Caliandro R, Triboli L, Esposito A, Benini S. A genome-wide analysis of desferrioxamine mediated iron uptake in Erwinia spp. reveals genes exclusive of the Rosaceae infecting strains. Sci Rep 2019; 9:2818. [PMID: 30808981 PMCID: PMC6391442 DOI: 10.1038/s41598-019-39787-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 01/29/2019] [Indexed: 11/17/2022] Open
Abstract
Erwinia amylovora is the etiological agent of fire blight, a devastating disease which is a global threat to commercial apple and pear production. The Erwinia genus includes a wide range of different species belonging to plant pathogens, epiphytes and even opportunistic human pathogens. The aim of the present study is to understand, within the Erwinia genus, the genetic differences between phytopathogenic strains and those strains not reported to be phytopathogenic. The genes related to the hydroxamate siderophores iron uptake have been considered due to their potential druggability. In E. amylovora siderophore-mediated iron acquisition plays a relevant role in the progression of Fire blight. Here we analyzed the taxonomic relations within Erwinia genus and the relevance of the genes related to the siderophore-mediated iron uptake pathway. The results of this study highlight the presence of a well-defined sub-group of Rosaceae infecting species taxonomically and genetically related with a high number of conserved core genes. The analysis of the complete ferrioxamine transport system has led to the identification of two genes exclusively present in the Rosaceae infecting strains.
Collapse
Affiliation(s)
- Ivan Polsinelli
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Luigimaria Borruso
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Rosanna Caliandro
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy
| | - Luca Triboli
- Centre for Integrative Biology, University of Trento, via Sommarive n. 9, 38123, Povo, Trento, Italy
| | - Alfonso Esposito
- Centre for Integrative Biology, University of Trento, via Sommarive n. 9, 38123, Povo, Trento, Italy.
| | - Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
| |
Collapse
|