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Ferreira MV, Naranjo E, Denis N, Cobine P, De La Fuente L, Siri MI. Calcium modulation of bacterial wilt disease on potato. Appl Environ Microbiol 2024; 90:e0024224. [PMID: 38690890 PMCID: PMC11107177 DOI: 10.1128/aem.00242-24] [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: 02/19/2024] [Accepted: 03/22/2024] [Indexed: 05/03/2024] Open
Abstract
Ralstonia solanacearum species complex (RSSC) is a phytopathogenic bacterial group that causes bacterial wilt in several crops, being potato (Solanum tuberosum) one of the most important hosts. The relationship between the potato plant ionome (mineral and trace elements composition) and the resistance levels to this pathogen has not been addressed until now. Mineral content of xylem sap, roots, stems and leaves of potato genotypes with different levels of resistance to bacterial wilt was assessed in this work, revealing a positive correlation between divalent calcium (Ca) cation concentrations and genotype resistance. The aim of this study was to investigate the effect of Ca on bacterial wilt resistance, and on the growth and virulence of RSSC. Ca supplementation significantly decreased the growth rate of Ralstonia pseudosolanacearum GMI1000 in minimal medium and affected several virulence traits such as biofilm formation and twitching motility. We also incorporate for the first time the use of microfluidic chambers to follow the pathogen growth and biofilm formation in conditions mimicking the plant vascular system. By using this approach, a reduction in biofilm formation was observed when both, rich and minimal media, were supplemented with Ca. Assessment of the effect of Ca amendments on bacterial wilt progress in potato genotypes revealed a significant delay in disease progress, or a complete absence of wilting symptoms in the case of partially resistant genotypes. This work contributes to the understanding of Ca effect on virulence of this important pathogen and provides new strategies for an integrated control of bacterial wilt on potato. IMPORTANCE Ralstonia solanacearum species complex (RSSC) includes a diverse group of bacterial strains that cause bacterial wilt. This disease is difficult to control due to pathogen aggressiveness, persistence, wide range of hosts, and wide geographic distribution in tropical, subtropical, and temperate regions. RSSC causes considerable losses depending on the pathogen strain, host, soil type, environmental conditions, and cultural practices. In potato, losses of $19 billion per year have been estimated for this pathogen worldwide. In this study, we report for the first time the mineral composition found in xylem sap and plant tissues of potato germplasm with different levels of resistance to bacterial wilt. This study underscores the crucial role of calcium (Ca) concentration in the xylem sap and stem in relation to the resistance of different genotypes. Our in vitro experiments provide evidence of Ca's inhibitory effect on the growth, biofilm formation, and twitching movement of the model RSSC strain R. pseudosolanacearum GMI1000. This study introduces a novel element, the Ca concentration, which should be included into the integrated disease control management strategies for bacterial wilt in potatoes.
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Affiliation(s)
- María Virginia Ferreira
- Área Microbiología, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Eber Naranjo
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - Nicol Denis
- Área Microbiología, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Paul Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA
| | - María Inés Siri
- Área Microbiología, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay
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Lipps S, Lipka AE, Mideros S, Jamann T. Inhibition of ethylene involved in resistance to E. turcicum in an exotic-derived double haploid maize population. FRONTIERS IN PLANT SCIENCE 2023; 14:1272951. [PMID: 37868313 PMCID: PMC10587583 DOI: 10.3389/fpls.2023.1272951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 09/19/2023] [Indexed: 10/24/2023]
Abstract
Northern corn leaf blight (NCLB) is an economically important disease of maize. While the genetic architecture of NCLB has been well characterized, the pathogen is known to overcome currently deployed resistance genes, and the role of hormones in resistance to NCLB is an area of active research. The objectives of the study were (i) to identify significant markers associated with resistance to NCLB, (ii) to identify metabolic pathways associated with NCLB resistance, and (iii) to examine role of ethylene in resistance to NCLB. We screened 252 lines from the exotic-derived double haploid BGEM maize population for resistance to NCLB in both field and greenhouse environments. We used a genome wide association study (GWAS) and stepwise regression to identify four markers associated with resistance, followed by a pathway association study tool (PAST) to identify important metabolic pathways associated with disease severity and incubation period. The ethylene synthesis pathway was significant for disease severity and incubation period. We conducted a greenhouse assay in which we inhibited ethylene to examine the role of ethylene in resistance to NCLB. We observed a significant increase in incubation period and a significant decrease in disease severity between plants treated with the ethylene inhibitor and mock-treated plants. Our study confirms the potential of the BGEM population as a source of novel alleles for resistance. We also confirm the role of ethylene in resistance to NCLB and contribute to the growing body of literature on ethylene and disease resistance in monocots.
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Affiliation(s)
| | | | | | - Tiffany Jamann
- Department of Crop Sciences, University of Illinois, Urbana, IL, United States
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Saquee FS, Norman PE, Saffa MD, Kavhiza NJ, Pakina E, Zargar M, Diakite S, Stybayev G, Baitelenova A, Kipshakbayeva G. Impact of different types of green manure on pests and disease incidence and severity as well as growth and yield parameters of maize. Heliyon 2023; 9:e17294. [PMID: 37383197 PMCID: PMC10293721 DOI: 10.1016/j.heliyon.2023.e17294] [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: 03/21/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/30/2023] Open
Abstract
The emergence of pests and diseases, including the maize streak virus, leaf blight, the African stem borer, and gray leaf spot, poses a persistent threat to maize production (Zea mays L. cv: DMR-ESR-Yellow) around the world. A field experiment was conducted at the School of Agriculture experimental site, Njala University, Sierra Leone, during a two-year period (2020-2021) to assess the effects of green manure on pest and disease incidence and severity as well as growth and yield parameters of maize. The experiment was laid out in a randomized complete block design (RCBD) with three replications and four treatments: Cal. 3 t.ha-1, Cal. 6 t.h-1, Pan. 3 t.h-1, Pan 6 t.ha-1 and a control plot amended with 200 kg ha-1 of N (urea) and NPK 15:15:15 ha-1 split application. The study showed that gray leaf spot damage was the most severe infection among all treatments. Therefore, the effects of the most severe disease and pest of maize in Sierra Leone can be minimized by applying green manure. Moreover, results reveal that Calopogonium- Pueraria mixture amended plots showed significant performance in the measured growth parameters viz. highest leaf number, large leaf area stem girth, superior plant height, best ear height (64.6-78.5 cm), higher cob yield (1.2-1.4 t.ha-1) ear (1.8-2.1 t.ha-1) and dry grain yield (0.5-0.7 ha-1). Panicum green manure results showed that prompt and adequate application, as well as decomposition of green manures, is imperative for the successful conservation and sustainability of maize farming systems. The findings of this research could improve the efficiency of green manure use in pest, disease, and crop management systems.
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Affiliation(s)
- Francess Sia Saquee
- Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia
- Faculty of Development Agriculture & Natural Resources Management, Eastern Technical University of Sierra Leone, Combema Road, Kenema City, 00232, Sierra Leone
| | - Prince Emmanuel Norman
- Sierra Leone Agricultural Research Institute (SLARI), PMB 1313, Tower Hill, Freetown, Sierra Leone
| | - Musa Decius Saffa
- Njala University, School of Agriculture and Food Sciences, Crop Protection Department, Sierra Leone
| | - Nyasha John Kavhiza
- Faculty of Development Agriculture & Natural Resources Management, Eastern Technical University of Sierra Leone, Combema Road, Kenema City, 00232, Sierra Leone
| | - Elena Pakina
- Faculty of Development Agriculture & Natural Resources Management, Eastern Technical University of Sierra Leone, Combema Road, Kenema City, 00232, Sierra Leone
| | - Meisam Zargar
- Faculty of Development Agriculture & Natural Resources Management, Eastern Technical University of Sierra Leone, Combema Road, Kenema City, 00232, Sierra Leone
| | - Simbo Diakite
- Faculty of Development Agriculture & Natural Resources Management, Eastern Technical University of Sierra Leone, Combema Road, Kenema City, 00232, Sierra Leone
| | - Gani Stybayev
- Department of Plant Protection, Faculty of Agronomy, S. Seifullin Kazakh Agrotechnical University, 010000, Astana, Kazakhstan
| | - Aliya Baitelenova
- Department of Plant Protection, Faculty of Agronomy, S. Seifullin Kazakh Agrotechnical University, 010000, Astana, Kazakhstan
| | - Gulden Kipshakbayeva
- Department of Plant Protection, Faculty of Agronomy, S. Seifullin Kazakh Agrotechnical University, 010000, Astana, Kazakhstan
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De La Fuente L, Merfa MV, Cobine PA, Coleman JJ. Pathogen Adaptation to the Xylem Environment. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:163-186. [PMID: 35472277 DOI: 10.1146/annurev-phyto-021021-041716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A group of aggressive pathogens have evolved to colonize the plant xylem. In this vascular tissue, where water and nutrients are transported from the roots to the rest of the plant, pathogens must be able to thrive under acropetal xylem sap flow and scarcity of nutrients while having direct contact only with predominantly dead cells. Nevertheless, a few bacteria have adapted to exclusively live in the xylem, and various pathogens may colonize other plant niches without causing symptoms unless they reach the xylem. Once established, the pathogens modulate its physicochemical conditions to enhance their growth and virulence. Adaptation to the restrictive lifestyle of the xylem leads to genome reduction in xylem-restricted bacteria, as they have a higher proportion of pseudogenes in their genome. The basis of xylem adaptation is not completely understood; therefore, a need still exists for model systems to advance the knowledge on this topic.
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Affiliation(s)
- Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
| | - Marcus V Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Jeffrey J Coleman
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
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Bartholomew HP, Reynoso G, Thomas BJ, Mullins CM, Smith C, Gentzel IN, Giese LA, Mackey D, Stevens AM. The Transcription Factor Lrp of Pantoea stewartii subsp. stewartii Controls Capsule Production, Motility, and Virulence Important for in planta Growth. Front Microbiol 2022; 12:806504. [PMID: 35237242 PMCID: PMC8882988 DOI: 10.3389/fmicb.2021.806504] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
The bacterial phytopathogen Pantoea stewartii subsp. stewartii causes leaf blight and Stewart's wilt disease in susceptible corn varieties. A previous RNA-Seq study examined P. stewartii gene expression patterns during late-stage infection in the xylem, and a Tn-Seq study using a P. stewartii mutant library revealed genes essential for colonization of the xylem. Based on these findings, strains with in-frame chromosomal deletions in the genes encoding seven transcription factors (NsrR, IscR, Nac, Lrp, DSJ_00125, DSJ_03645, and DSJ_18135) and one hypothetical protein (DSJ_21690) were constructed to further evaluate the role of the encoded gene products during in vitro and in planta growth. Assays for capsule production and motility indicate that Lrp plays a role in regulating these two key physiological outputs in vitro. Single infections of each deletion strain into the xylem of corn seedlings determined that Lrp plays a significant role in P. stewartii virulence. In planta xylem competition assays between co-inoculated deletion and the corresponding complementation or wild-type strains as well as in vitro growth curves determined that Lrp controls functions important for P. stewartii colonization and growth in corn plants, whereas IscR may have a more generalized impact on growth. Defining the role of essential transcription factors, such as Lrp, during in planta growth will enable modeling of key components of the P. stewartii regulatory network utilized during growth in corn plants.
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Affiliation(s)
| | - Guadalupe Reynoso
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Brandi J. Thomas
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chase M. Mullins
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chastyn Smith
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Irene N. Gentzel
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
| | - Laura A. Giese
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
| | - David Mackey
- Department of Horticulture & Crop Science, The Ohio State University, Columbus, OH, United States
- Department of Molecular Genetics and Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States
| | - Ann M. Stevens
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
- Center for Emerging, Zoonotic and Arthropod-Borne Pathogens, Virginia Tech, Blacksburg, VA, United States
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Mullens A, Jamann TM. Colonization and Movement of Green Fluorescent Protein-Labeled Clavibacter nebraskensis in Maize. PLANT DISEASE 2021; 105:1422-1431. [PMID: 33190611 DOI: 10.1094/pdis-08-20-1823-re] [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: 06/11/2023]
Abstract
Clavibacter nebraskensis causes Goss's bacterial wilt and leaf blight, a major disease of maize. Infected crop residue is the primary inoculum source and infection can occur via wounds or natural openings, such as stomata or hydathodes. The use of resistant hybrids is the primary control method for Goss's wilt. In this study, colonization and movement patterns of C. nebraskensis during infection were examined using green fluorescent protein (GFP)-labeled bacterial strains. We successfully introduced a plasmid to C. nebraskensis via electroporation, which resulted in GFP accumulation. Fluorescence microscopy revealed that in the absence of wounding, bacteria colonize leaf tissue via entry through the hydathodes when guttation droplets are present. Stomatal penetration was not observed under natural conditions. Bacteria initially colonize the xylem and subsequently the mesophyll, which creates the freckles that are characteristic of the disease. Bacteria infiltrated into the mesophyll did not cause disease symptoms, could not enter the vasculature, and did not spread from the initial inoculation point. Bacteria were observed exuding through stomata onto the leaf surface, resulting in the characteristic sheen of diseased leaves. Resistant maize lines exhibited decreased bacterial spread in the vasculature and the mesophyll. These tools to examine C. nebraskensis movement offer opportunities and new insights into the pathogenesis process and can form the basis for improved Goss's wilt management through host resistance.
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Affiliation(s)
- Alexander Mullens
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
| | - Tiffany M Jamann
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
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Li Y, Li Q, Chen S. Diazotroph Paenibacillus triticisoli BJ-18 Drives the Variation in Bacterial, Diazotrophic and Fungal Communities in the Rhizosphere and Root/Shoot Endosphere of Maize. Int J Mol Sci 2021; 22:1460. [PMID: 33540521 PMCID: PMC7867140 DOI: 10.3390/ijms22031460] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/28/2022] Open
Abstract
Application of diazotrophs (N2-fixing microorganisms) can decrease the overuse of nitrogen (N) fertilizer. Until now, there are few studies on the effects of diazotroph application on microbial communities of major crops. In this study, the diazotrophic and endospore-forming Paenibacillus triticisoli BJ-18 was inoculated into maize soils containing different N levels. The effects of inoculation on the composition and abundance of the bacterial, diazotrophic and fungal communities in the rhizosphere and root/shoot endosphere of maize were evaluated by sequencing the 16S rRNA, nifH gene and ITS (Inter Transcribed Spacer) region. P. triticisoli BJ-18 survived and propagated in all the compartments of the maize rhizosphere, root and shoot. The abundances and diversities of the bacterial and diazotrophic communities in the rhizosphere were significantly higher than in both root and shoot endospheres. Each compartment of the rhizosphere, root and shoot had its specific bacterial and diazotrophic communities. Our results showed that inoculation reshaped the structures of the bacterial, diazotrophic and fungal communities in the maize rhizosphere and endosphere. Inoculation reduced the interactions of the bacteria and diazotrophs in the rhizosphere and endosphere, while it increased the fungal interactions. After inoculation, the abundances of Pseudomonas, Bacillus and Paenibacillus in all three compartments, Klebsiella in the rhizosphere and Paenibacillus in the root and shoot were significantly increased, while the abundances of Fusarium and Giberella were greatly reduced. Paenibacillus was significantly correlated with plant dry weight, nitrogenase, N2-fixing rate, P solubilization and other properties of the soil and plant.
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Affiliation(s)
| | | | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing 100094, China; (Y.L.); (Q.L.)
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Ding Y, Weckwerth PR, Poretsky E, Murphy KM, Sims J, Saldivar E, Christensen SA, Char SN, Yang B, Tong AD, Shen Z, Kremling KA, Buckler ES, Kono T, Nelson DR, Bohlmann J, Bakker MG, Vaughan MM, Khalil AS, Betsiashvili M, Dressano K, Köllner TG, Briggs SP, Zerbe P, Schmelz EA, Huffaker A. Genetic elucidation of interconnected antibiotic pathways mediating maize innate immunity. NATURE PLANTS 2020; 6:1375-1388. [PMID: 33106639 DOI: 10.1038/s41477-020-00787-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 09/11/2020] [Indexed: 05/24/2023]
Abstract
Specialized metabolites constitute key layers of immunity that underlie disease resistance in crops; however, challenges in resolving pathways limit our understanding of the functions and applications of these metabolites. In maize (Zea mays), the inducible accumulation of acidic terpenoids is increasingly considered to be a defence mechanism that contributes to disease resistance. Here, to understand maize antibiotic biosynthesis, we integrated association mapping, pan-genome multi-omic correlations, enzyme structure-function studies and targeted mutagenesis. We define ten genes in three zealexin (Zx) gene clusters that encode four sesquiterpene synthases and six cytochrome P450 proteins that collectively drive the production of diverse antibiotic cocktails. Quadruple mutants in which the ability to produce zealexins (ZXs) is blocked exhibit a broad-spectrum loss of disease resistance. Genetic redundancies ensuring pathway resiliency to single null mutations are combined with enzyme substrate promiscuity, creating a biosynthetic hourglass pathway that uses diverse substrates and in vivo combinatorial chemistry to yield complex antibiotic blends. The elucidated genetic basis of biochemical phenotypes that underlie disease resistance demonstrates a predominant maize defence pathway and informs innovative strategies for transferring chemical immunity between crops.
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Affiliation(s)
- Yezhang Ding
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Philipp R Weckwerth
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Elly Poretsky
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Katherine M Murphy
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - James Sims
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Evan Saldivar
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Department of Agriculture, Agricultural Research Service, Gainesville, FL, USA
| | - Si Nian Char
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Bing Yang
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Donald Danforth Plant Science Center, St Louis, MO, USA
| | - Anh-Dao Tong
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Zhouxin Shen
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Karl A Kremling
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Edward S Buckler
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
- Robert W. Holley Center for Agriculture and Health, Ithaca, US Department of Agriculture, Agricultural Research Service, New York, NY, USA
| | - Tom Kono
- Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN, USA
| | - David R Nelson
- University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jörg Bohlmann
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew G Bakker
- National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, Peoria, IL, USA
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, Peoria, IL, USA
| | - Ahmed S Khalil
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Mariam Betsiashvili
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Keini Dressano
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | | | - Steven P Briggs
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Philipp Zerbe
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA.
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