1
|
Asadi M, Hamilton D, Shomachuk C, Oloye FF, De Lange C, Pu X, Osunla CA, Cantin J, El-Baroudy S, Mejia EM, Gregorchuk B, Becker MG, Mangat C, Brinkmann M, Jones PD, Giesy JP, McPhedran KN. Assessment of rapid wastewater surveillance for determination of communicable disease spread in municipalities. Sci Total Environ 2023; 901:166541. [PMID: 37625717 DOI: 10.1016/j.scitotenv.2023.166541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/02/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
Wastewater surveillance (WS) helps to improve the understanding of the spread of communicable diseases in communities. WS can assist public health decision-makers in the design and implementation of timely mitigation measures. There is an increased need to use reliable, cost-effective, simple, and rapid WS systems, given traditional analytical (or 'gold-standard') programs are instrument/time-intensive, and dependent on highly skilled personnel. This study investigated the application of the portable GeneXpert platform for WS of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), influenza B virus (IBV), and respiratory syncytial virus (RSV). The GeneXpert system with the Xpert Xpress-SARS-CoV-2/Flu/RSV test kit uses reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to analyze wastewater samples. From September 2022 through January 2023, wastewater samples were collected from the influents of municipal wastewater treatment plants (MWTPs) of Saskatoon, Prince Albert, and North Battleford in the province of Saskatchewan, Canada. Both raw and concentrated wastewater samples were subjected to the GeneXpert analysis. Results showed that the Saskatoon wastewater viral loads were significantly correlated to Saskatchewan's influenza and COVID-19 clinical cases, with a lead time of 10 days for IAV and a lag time of 4 days for SARS-CoV-2. Additionally, the GeneXpert analysis of the three cities' wastewater samples showed that the raw WS could capture the dynamics of SARS-CoV-2 and IAV due to their correlation with concentrated WS. Interestingly, IBV loads were not detected in any wastewater samples, while the Saskatoon and Prince Albert wastewater samples collected following the 2023 holiday season (end of December and beginning of January) were positive for RSV. This study indicates that the GeneXpert has excellent potential for use in the development of an early warning system for transmissible disease in municipalities and limited-resource communities while simultaneously providing stakeholders with an efficient WS methodology.
Collapse
Affiliation(s)
- Mohsen Asadi
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Daniel Hamilton
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - Corwyn Shomachuk
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - Femi F Oloye
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Chantel De Lange
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Xia Pu
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Charles A Osunla
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jenna Cantin
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Seba El-Baroudy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Edgard M Mejia
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Branden Gregorchuk
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Michael G Becker
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Chand Mangat
- Wastewater Surveillance Unit, On-Health Division, National Microbiology Laboratory - Winnipeg, Public Health Agency of Canada, Canada
| | - Markus Brinkmann
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada; Department of Environmental Sciences, Baylor University, Waco, TX, USA; Department of Integrative Biology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Kerry N McPhedran
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada.
| |
Collapse
|
2
|
Johnson G, Gregorchuk BSJ, Zubrzycki A, Kolsun K, Meyers AFA, Sandstrom PA, Becker MG. Clinical evaluation of the GeneXpert ® Xpert ® Xpress SARS-CoV-2/Flu/RSV PLUS combination test. Can J Microbiol 2023; 69:146-150. [PMID: 36657122 DOI: 10.1139/cjm-2022-0204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The GeneXpert® Xpert® Xpress SARS-CoV-2/Flu/RSV PLUS combination test (PLUS assay) received Health Canada approval in January 2022. The PLUS assay is similar to the SARS-CoV-2/Flu/RSV combination test, with modifications to improve assay robustness against circulating and emerging variants. The performance characteristics of the PLUS assay were assessed at the Lakeridge Health Oshawa Hospital Centre and the National Microbiology Laboratory of Canada. The PLUS assay was directly compared to the SARS-CoV-2/Flu/RSV combination test using SARS-CoV-2 culture from five variants and remnant clinical specimens collected across the coronavirus disease 2019 pandemic. This included 50 clinical specimens negative for all pathogens, 110 clinical specimens positive for SARS-CoV-2, influenza A, influenza B, RSVA, and(or) RSVB and an additional 11 mixed samples to screen for target interactions. The PLUS assay showed a high % agreement with the widely used SARS-CoV-2/Flu/RSV combination test. Based on these findings, the PLUS assay and the Xpert SARS-CoV-2/Flu/RSV combination test results are largely consistent with no observed difference in sensitivity, specificity, or time to result when challenged with various SARS-CoV-2 variants. The reported cycle threshold (Ct) values provided by the new PLUS assay were also unchanged, with the exception of a possible 1-2 decrease reported in Ct for RSVA across a limited sample size.
Collapse
Affiliation(s)
- Grant Johnson
- Laboratory Medicine and Infection Prevention and Control, Lakeridge Health, Oshawa, ON, Canada.,Ontario Tech University, Oshawa, ON, Canada
| | - Branden S J Gregorchuk
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory Branch, JC Wilt Infectious Diseases Research Centre, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Arek Zubrzycki
- Laboratory Medicine and Infection Prevention and Control, Lakeridge Health, Oshawa, ON, Canada
| | - Kurt Kolsun
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory Branch, JC Wilt Infectious Diseases Research Centre, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Adrienne F A Meyers
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory Branch, JC Wilt Infectious Diseases Research Centre, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Paul A Sandstrom
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory Branch, JC Wilt Infectious Diseases Research Centre, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Michael G Becker
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory Branch, JC Wilt Infectious Diseases Research Centre, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
3
|
Walker PL, Girard IJ, Becker MG, Giesbrecht S, Whyard S, Fernando WGD, de Kievit TR, Belmonte MF. Tissue-specific mRNA profiling of the Brassica napus-Sclerotinia sclerotiorum interaction uncovers novel regulators of plant immunity. J Exp Bot 2022; 73:6697-6710. [PMID: 35961003 DOI: 10.1093/jxb/erac333] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 08/10/2022] [Indexed: 05/05/2023]
Abstract
White mold is caused by the fungal pathogen Sclerotinia sclerotiorum and leads to rapid and significant loss in plant yield. Among its many brassicaceous hosts, including Brassica napus (canola) and Arabidopsis, the response of individual tissue layers directly at the site of infection has yet to be explored. Using laser microdissection coupled with RNA sequencing, we profiled the epidermis, mesophyll, and vascular leaf tissue layers of B. napus in response to S. sclerotiorum. High-throughput tissue-specific mRNA sequencing increased the total number of detected transcripts compared with whole-leaf assessments and provided novel insight into the conserved and specific roles of ontogenetically distinct leaf tissue layers in response to infection. When subjected to pathogen infection, the epidermis, mesophyll, and vasculature activate both specific and shared gene sets. Putative defense genes identified through transcription factor network analysis were then screened for susceptibility against necrotrophic, hemi-biotrophic, and biotrophic pathogens. Arabidopsis deficient in PR5-like RECEPTOR KINASE (PR5K) mRNA levels were universally susceptible to all pathogens tested and were further characterized to identify putative interacting partners involved in the PR5K signaling pathway. Together, these data provide insight into the complexity of the plant defense response directly at the site of infection.
Collapse
Affiliation(s)
- Philip L Walker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Ian J Girard
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shayna Giesbrecht
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Steve Whyard
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | - Teresa R de Kievit
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
4
|
Patriquin G, Davidson RJ, Hatchette TF, Head BM, Mejia E, Becker MG, Meyers A, Sandstrom P, Hatchette J, Block A, Smith N, Ross J, LeBlanc JJ. Generation of False-Positive SARS-CoV-2 Antigen Results with Testing Conditions outside Manufacturer Recommendations: A Scientific Approach to Pandemic Misinformation. Microbiol Spectr 2021; 9:e0068321. [PMID: 34668722 PMCID: PMC8528119 DOI: 10.1128/spectrum.00683-21] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/29/2021] [Indexed: 11/20/2022] Open
Abstract
Antigen-based rapid diagnostics tests (Ag-RDTs) are useful tools for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. However, misleading demonstrations of the Abbott Panbio coronavirus disease 2019 (COVID-19) Ag-RDT on social media claimed that SARS-CoV-2 antigen could be detected in municipal water and food products. To offer a scientific rebuttal to pandemic misinformation and disinformation, this study explored the impact of using the Panbio SARS-CoV-2 assay with conditions falling outside manufacturer recommendations. Using Panbio, various water and food products, laboratory buffers, and SARS-CoV-2-negative clinical specimens were tested with and without manufacturer buffer. Additional experiments were conducted to assess the role of each Panbio buffer component (tricine, NaCl, pH, and Tween 20) as well as the impact of temperature (4°C, 20°C, and 45°C) and humidity (90%) on assay performance. Direct sample testing (without the kit buffer) resulted in false-positive signals resembling those obtained with SARS-CoV-2 positive controls tested under proper conditions. The likely explanation of these artifacts is nonspecific interactions between the SARS-CoV-2-specific conjugated and capture antibodies, as proteinase K treatment abrogated this phenomenon, and thermal shift assays showed pH-induced conformational changes under conditions promoting artifact formation. Omitting, altering, and reverse engineering the kit buffer all supported the importance of maintaining buffering capacity, ionic strength, and pH for accurate kit function. Interestingly, the Panbio assay could tolerate some extremes of temperature and humidity outside manufacturer claims. Our data support strict adherence to manufacturer instructions to avoid false-positive SARS-CoV-2 Ag-RDT reactions, otherwise resulting in anxiety, overuse of public health resources, and dissemination of misinformation. IMPORTANCE With the Panbio severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test being deployed in over 120 countries worldwide, understanding conditions required for its ideal performance is critical. Recently on social media, this kit was shown to generate false positives when manufacturer recommendations were not followed. While erroneous results from improper use of a test may not be surprising to some health care professionals, understanding why false positives occur can help reduce the propagation of misinformation and provide a scientific rebuttal for these aberrant findings. This study demonstrated that the kit buffer's pH, ionic strength, and buffering capacity were critical components to ensure proper kit function and avoid generation of false-positive results. Typically, false positives arise from cross-reacting or interfering substances; however, this study demonstrated a mechanism where false positives were generated under conditions favoring nonspecific interactions between the two antibodies designed for SARS-CoV-2 antigen detection. Following the manufacturer instructions is critical for accurate test results.
Collapse
Affiliation(s)
- Glenn Patriquin
- Division of Microbiology, Department of Pathology and Laboratory Medicine, Nova Scotia Health (NSH), Halifax, Nova Scotia, Canada
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ross J. Davidson
- Division of Microbiology, Department of Pathology and Laboratory Medicine, Nova Scotia Health (NSH), Halifax, Nova Scotia, Canada
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Todd F. Hatchette
- Division of Microbiology, Department of Pathology and Laboratory Medicine, Nova Scotia Health (NSH), Halifax, Nova Scotia, Canada
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Breanne M. Head
- National Microbiology Laboratory (NML), Public Health Agency of Canada (PHAC), Winnipeg, Manitoba, Canada
| | - Edgard Mejia
- National Microbiology Laboratory (NML), Public Health Agency of Canada (PHAC), Winnipeg, Manitoba, Canada
| | - Michael G. Becker
- National Microbiology Laboratory (NML), Public Health Agency of Canada (PHAC), Winnipeg, Manitoba, Canada
| | - Adrienne Meyers
- National Microbiology Laboratory (NML), Public Health Agency of Canada (PHAC), Winnipeg, Manitoba, Canada
| | - Paul Sandstrom
- National Microbiology Laboratory (NML), Public Health Agency of Canada (PHAC), Winnipeg, Manitoba, Canada
| | | | - Ava Block
- Praxes Medical Group, Halifax, Nova Scotia, Canada
| | - Nicole Smith
- Praxes Medical Group, Halifax, Nova Scotia, Canada
| | - John Ross
- Praxes Medical Group, Halifax, Nova Scotia, Canada
| | - Jason J. LeBlanc
- Division of Microbiology, Department of Pathology and Laboratory Medicine, Nova Scotia Health (NSH), Halifax, Nova Scotia, Canada
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Medicine (Infectious Diseases), Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
5
|
Johnson G, Zubrzycki A, Henry M, Ranadheera C, Corbett C, Meyers AF, Sandstrom PA, Becker MG. Clinical evaluation of the GeneXpert® Xpert® Xpress SARS-CoV-2/Flu/RSV combination test. Journal of Clinical Virology Plus 2021; 1:100014. [PMID: 35262002 PMCID: PMC8040320 DOI: 10.1016/j.jcvp.2021.100014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 02/07/2023] Open
|
6
|
Becker MG, Liang D, Cooper B, Le Y, Taylor T, Lee ER, Wu S, Sandstrom P, Ji H. Development and Application of Performance Assessment Criteria for Next-Generation Sequencing-Based HIV Drug Resistance Assays. Viruses 2020; 12:E627. [PMID: 32532083 PMCID: PMC7354553 DOI: 10.3390/v12060627] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/29/2020] [Accepted: 06/07/2020] [Indexed: 12/19/2022] Open
Abstract
Next-generation sequencing (NGS)-based HIV drug resistance (HIVDR) assays outperform conventional Sanger sequencing in scalability, sensitivity, and quantitative detection of minority resistance variants. Thus far, HIVDR assays have been applied primarily in research but rarely in clinical settings. One main obstacle is the lack of standardized validation and performance evaluation systems that allow regulatory agencies to benchmark and accredit new assays for clinical use. By revisiting the existing principles for molecular assay validation, here we propose a new validation and performance evaluation system that helps to both qualitatively and quantitatively assess the performance of an NGS-based HIVDR assay. To accomplish this, we constructed a 70-specimen proficiency test panel that includes plasmid mixtures at known ratios, viral RNA from infectious clones, and anonymized clinical specimens. We developed assessment criteria and benchmarks for NGS-based HIVDR assays and used these to assess data from five separate MiSeq runs performed in two experienced HIVDR laboratories. This proposed platform may help to pave the way for the standardization of NGS HIVDR assay validation and performance evaluation strategies for accreditation and quality assurance purposes in both research and clinical settings.
Collapse
Affiliation(s)
- Michael G. Becker
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Dun Liang
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Breanna Cooper
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Yan Le
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Tracy Taylor
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Emma R. Lee
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Sutan Wu
- SutanStats, St. Louis, MO 63017, USA;
| | - Paul Sandstrom
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Hezhao Ji
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| |
Collapse
|
7
|
Becker MG, Haddadi P, Wan J, Adam L, Walker P, Larkan NJ, Daayf F, Borhan MH, Belmonte MF. Transcriptome Analysis of Rlm2-Mediated Host Immunity in the Brassica napus- Leptosphaeria maculans Pathosystem. Mol Plant Microbe Interact 2019; 32:1001-1012. [PMID: 30938576 DOI: 10.1094/mpmi-01-19-0028-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Our study investigated disease resistance in the Brassica napus-Leptosphaeria maculans pathosystem using a combination of laser microdissection, dual RNA sequencing, and physiological validations of large-scale gene sets. The use of laser microdissection improved pathogen detection and identified putative L. maculans effectors and lytic enzymes operative during host colonization. Within 24 h of inoculation, we detected large shifts in gene activity in resistant cotyledons associated with jasmonic acid and calcium signaling pathways that accelerated the plant defense response. Sequencing data were validated through the direct quantification of endogenous jasmonic acid levels. Additionally, resistance against L. maculans was abolished when the calcium chelator EGTA was applied to the inoculation site, providing physiological evidence of the role of calcium in B. napus immunity against L. maculans. We integrated gene expression data with all available information on cis-regulatory elements and transcription factor binding affinities to better understand the gene regulatory networks underpinning plant resistance to hemibiotrophic pathogens. These in silico analyses point to early cellular reprogramming during host immunity that are coordinated by CAMTA, BZIP, and bHLH transcription factors. Together, we provide compelling genetic and physiological evidence into the programming of plant resistance against fungal pathogens.
Collapse
Affiliation(s)
- Michael G Becker
- 1Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Parham Haddadi
- 2Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, SK S7N 0X2, Canada
| | - Joey Wan
- 1Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Lorne Adam
- 3Department of Plant Science, University of Manitoba
| | - Philip Walker
- 1Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | - Fouad Daayf
- 3Department of Plant Science, University of Manitoba
| | - M Hossein Borhan
- 2Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, SK S7N 0X2, Canada
| | - Mark F Belmonte
- 1Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
8
|
Youssef MS, Mira MM, Millar JL, Becker MG, Belmonte MF, Hill RD, Stasolla C. Spatial identification of transcripts and biological processes in laser micro-dissected sub-regions of waterlogged corn roots with altered expression of phytoglobin. Plant Physiol Biochem 2019; 139:350-365. [PMID: 30952087 DOI: 10.1016/j.plaphy.2019.03.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/25/2019] [Accepted: 03/25/2019] [Indexed: 05/27/2023]
Abstract
Over-expression of the corn phytoglobin ZmPgb1.2 increases tolerance to waterlogging, while suppression of ZmPgb1.2 compromises plant growth. To unravel compartment-specific transcriptional changes evoked by ZmPgb1.2 during hypoxia, laser micro-dissected sub-regions from waterlogged roots of WT and ZmPgb1.2 overexpressing [ZmPgb1.2(S)] plants were probed for global transcriptional analysis using next generation RNA sequencing. These sub-regions included compartments within the meristematic, elongation, and maturation zone. Of the 149 genes differentially expressed by the up-regulation of ZmPgb1.2, 78 occurred within the meristematic region and included genes involved in jasmonic acid synthesis and response, ascorbic acid metabolism, and ethylene signalling. The ZmPgb1.2 regulation of these genes, discussed in the context of known functions of Pgbs, was further validated by monitoring their expression in meristematic cells of waterlogged roots suppressing ZmPgb1.2. Of the 27 genes differentially expressed by the over-expression of ZmPgb1.2 in the elongation zone, pyruvate kinase and alcohol dehydrogenase showed an expression pattern correlated to the level of ZmPgb1.2 in the tissue. The transcriptional induction of these two enzymes in hypoxic domains of the elongation zone over-expressing ZmPgb1.2 suggests the activation of the fermentation pathway which might be required to sustain metabolic flux and production of ATP in support of cell elongation.
Collapse
Affiliation(s)
- Mohamed S Youssef
- Botany Department, Faculty of Science, Kafrelsheikh University, 33516, Kafr El-Sheikh, Egypt
| | - Mohamed M Mira
- Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Gharbia, Egypt
| | - Jenna L Millar
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Robert D Hill
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
| |
Collapse
|
9
|
Ziegler DJ, Khan D, Kalichuk JL, Becker MG, Belmonte MF. Transcriptome landscape of the early Brassica napus seed. J Integr Plant Biol 2019; 61:639-650. [PMID: 30941858 DOI: 10.1111/jipb.12812] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/26/2019] [Indexed: 05/05/2023]
Abstract
Brassica napus L. (canola) is one of the world's most economically important oilseeds. Despite our growing knowledge of Brassica genetics, we still know little about the genes and gene regulatory networks underlying early seed development. In this work, we use laser microdissection coupled with RNA sequencing to profile gene activity of both the maternal and filial subregions of the globular seed. We find subregions of the chalazal end including the chalazal endosperm, chalazal proliferating tissue, and chalazal seed coat, have unique transcriptome profiles associated with hormone biosynthesis and polysaccharide metabolism. We confirm that the chalazal seed coat is uniquely enriched for sucrose biosynthesis and transport, and that the chalazal endosperm may function as an important regulator of the maternal region through brassinosteroid synthesis. The chalazal proliferating tissue, a poorly understood subregion, was specifically enriched in transcripts associated with megasporogenesis and trehalose biosynthesis, suggesting this ephemeral structure plays an important role in both sporophytic development and carbon nutrient balance, respectively. Finally, compartmentalization of transcription factors and their regulatory circuits has uncovered previously unknown roles for the chalazal pole in early seed development.
Collapse
Affiliation(s)
| | - Deirdre Khan
- University of Manitoba, Winnipeg, Manitoba, Canada
| | | | | | | |
Collapse
|
10
|
Elshobary ME, Becker MG, Kalichuk JL, Chan AC, Belmonte MF, Piercey-Normore MD. Tissue-specific localization of polyketide synthase and other associated genes in the lichen, Cladonia rangiferina, using laser microdissection. Phytochemistry 2018; 156:142-150. [PMID: 30296707 DOI: 10.1016/j.phytochem.2018.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 08/25/2018] [Accepted: 09/28/2018] [Indexed: 02/05/2023]
Abstract
The biosynthesis of two polyketides, atranorin and fumarprotocetraric acid, produced from a lichen-forming fungus, Cladonia rangiferina (L.) F. H. Wigg. was correlated with the expression of eight fungal genes (CrPKS1, CrPKS3, CrPKS16, Catalase (CAT), Sugar Transporter (MFsug), Dioxygenase (YQE1), C2H2 Transcription factor (C2H2), Transcription Factor PacC (PacC), which are thought to be involved in polyketide biosynthesis, and one algal gene, NAD-dependent deacetylase sirtuin 2 (AsNAD)), using laser microdissection (LMD). The differential gene expression levels within the thallus tissue layers demonstrate that the most active region for potential polyketide biosynthesis within the lichen is the outer apical region proximal to the photobiont but some expression also occurs in reproductive tissue. This is the first study using laser microdissection to explore gene expression of these nine genes and their location of expression; it provides a proof-of-concept for future experiments exploring tissue-specific gene expression within lichens; and it highlights the utility of LMD for use in lichen systems.
Collapse
Affiliation(s)
| | - Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
| | - Jenna L Kalichuk
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
| | - Ainsley C Chan
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
| | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
| | - Michele D Piercey-Normore
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada; School of Science and the Environment, Memorial University of Newfoundland (Grenfell Campus), Corner Brook, NL, A2H 5G4, Canada.
| |
Collapse
|
11
|
Girard IJ, Tong C, Becker MG, Mao X, Huang J, de Kievit T, Fernando WGD, Liu S, Belmonte MF. RNA sequencing of Brassica napus reveals cellular redox control of Sclerotinia infection. J Exp Bot 2017; 68:5079-5091. [PMID: 29036633 PMCID: PMC5853404 DOI: 10.1093/jxb/erx338] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/14/2017] [Indexed: 05/12/2023]
Abstract
Brassica napus is one of the world's most valuable oilseeds and is under constant pressure by the necrotrophic fungal pathogen, Sclerotinia sclerotiorum, the causal agent of white stem rot. Despite our growing understanding of host pathogen interactions at the molecular level, we have yet to fully understand the biological processes and underlying gene regulatory networks responsible for determining disease outcomes. Using global RNA sequencing, we profiled gene activity at the first point of infection on the leaf surface 24 hours after pathogen exposure in susceptible (B. napus cv. Westar) and tolerant (B. napus cv. Zhongyou 821) plants. We identified a family of ethylene response factors that may contribute to host tolerance to S. sclerotiorum by activating genes associated with fungal recognition, subcellular organization, and redox homeostasis. Physiological investigation of redox homeostasis was further studied by quantifying cellular levels of the glutathione and ascorbate redox pathway and the cycling enzymes associated with host tolerance to S. sclerotiorum. Functional characterization of an Arabidopsis redox mutant challenged with the fungus provides compelling evidence into the role of the ascorbate-glutathione redox hub in the maintenance and enhancement of plant tolerance against fungal pathogens.
Collapse
Affiliation(s)
- Ian J Girard
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Chaobo Tong
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, The Key Laboratory of Biology and Genetic Improvement of Oil Crops, The Ministry of Agriculture, Wuhan 430062, Hubei, China
| | - Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Xingyu Mao
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Junyan Huang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, The Key Laboratory of Biology and Genetic Improvement of Oil Crops, The Ministry of Agriculture, Wuhan 430062, Hubei, China
| | - Teresa de Kievit
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | - Shengyi Liu
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, The Key Laboratory of Biology and Genetic Improvement of Oil Crops, The Ministry of Agriculture, Wuhan 430062, Hubei, China
| | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
12
|
Duke KA, Becker MG, Girard IJ, Millar JL, Dilantha Fernando WG, Belmonte MF, de Kievit TR. The biocontrol agent Pseudomonas chlororaphis PA23 primes Brassica napus defenses through distinct gene networks. BMC Genomics 2017. [PMID: 28629321 PMCID: PMC5477169 DOI: 10.1186/s12864-017-3848-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Background The biological control agent Pseudomonas chlororaphis PA23 is capable of protecting Brassica napus (canola) from the necrotrophic fungus Sclerotinia sclerotiorum via direct antagonism. While we have elucidated bacterial genes and gene products responsible biocontrol, little is known about how the host plant responds to bacterial priming on the leaf surface, including global changes in gene activity in the presence and absence of S. sclerotiorum. Results Application of PA23 to the aerial surfaces of canola plants reduced the number of S. sclerotiorum lesion-forming petals by 91.1%. RNA sequencing of the host pathogen interface showed that pretreatment with PA23 reduced the number of genes upregulated in response to S. sclerotiorum by 16-fold. By itself, PA23 activated unique defense networks indicative of defense priming. Genes encoding MAMP-triggered immunity receptors detecting flagellin and peptidoglycan were downregulated in PA23 only-treated plants, consistent with post-stimulus desensitization. Downstream, we observed reactive oxygen species (ROS) production involving low levels of H2O2 and overexpression of genes associated with glycerol-3-phosphate (G3P)-mediated systemic acquired resistance (SAR). Leaf chloroplasts exhibited increased thylakoid membrane structures and chlorophyll content, while lipid metabolic processes were upregulated. Conclusion In addition to directly antagonizing S. sclerotiorum, PA23 primes the plant defense response through induction of unique local and systemic defense networks. This study provides novel insight into the effects of biocontrol agents applied to the plant phyllosphere. Understanding these interactions will aid in the development of biocontrol systems as an alternative to chemical pesticides for protection of important crop systems. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3848-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kelly A Duke
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Ian J Girard
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Jenna L Millar
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | | | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Teresa R de Kievit
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
| |
Collapse
|
13
|
Becker MG, Walker PL, Pulgar-Vidal NC, Belmonte MF. SeqEnrich: A tool to predict transcription factor networks from co-expressed Arabidopsis and Brassica napus gene sets. PLoS One 2017; 12:e0178256. [PMID: 28575075 PMCID: PMC5456048 DOI: 10.1371/journal.pone.0178256] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 05/10/2017] [Indexed: 01/08/2023] Open
Abstract
Transcription factors and their associated DNA binding sites are key regulatory elements of cellular differentiation, development, and environmental response. New tools that predict transcriptional regulation of biological processes are valuable to researchers studying both model and emerging-model plant systems. SeqEnrich predicts transcription factor networks from co-expressed Arabidopsis or Brassica napus gene sets. The networks produced by SeqEnrich are supported by existing literature and predicted transcription factor–DNA interactions that can be functionally validated at the laboratory bench. The program functions with gene sets of varying sizes and derived from diverse tissues and environmental treatments. SeqEnrich presents as a powerful predictive framework for the analysis of Arabidopsis and Brassica napus co-expression data, and is designed so that researchers at all levels can easily access and interpret predicted transcriptional circuits. The program outperformed its ancestral program ChipEnrich, and produced detailed transcription factor networks from Arabidopsis and Brassica napus gene expression data. The SeqEnrich program is ideal for generating new hypotheses and distilling biological information from large-scale expression data.
Collapse
Affiliation(s)
- Michael G. Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Philip L. Walker
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Mark F. Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
| |
Collapse
|
14
|
Becker MG, Zhang X, Walker PL, Wan JC, Millar JL, Khan D, Granger MJ, Cavers JD, Chan AC, Fernando DWG, Belmonte MF. Transcriptome analysis of the Brassica napus-Leptosphaeria maculans pathosystem identifies receptor, signaling and structural genes underlying plant resistance. Plant J 2017; 90:573-586. [PMID: 28222234 DOI: 10.1111/tpj.13514] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 02/05/2017] [Accepted: 02/10/2017] [Indexed: 05/18/2023]
Abstract
The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant loss of yield worldwide. While genetic resistance has been used to mitigate the disease by means of traditional breeding strategies, there is little knowledge about the genes that contribute to blackleg resistance. RNA sequencing and a streamlined bioinformatics pipeline identified unique genes and plant defense pathways specific to plant resistance in the B. napus-L. maculans LepR1-AvrLepR1 interaction over time. We complemented our temporal analyses by monitoring gene activity directly at the infection site using laser microdissection coupled to quantitative PCR. Finally, we characterized genes involved in plant resistance to blackleg in the Arabidopsis-L. maculans model pathosystem. Data reveal an accelerated activation of the plant transcriptome in resistant host cotyledons associated with transcripts coding for extracellular receptors and phytohormone signaling molecules. Functional characterization provides direct support for transcriptome data and positively identifies resistance regulators in the Brassicaceae. Spatial gradients of gene activity were identified in response to L. maculans proximal to the site of infection. This dataset provides unprecedented spatial and temporal resolution of the genes required for blackleg resistance and serves as a valuable resource for those interested in host-pathogen interactions.
Collapse
Affiliation(s)
- Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Xuehua Zhang
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Philip L Walker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Joey C Wan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Jenna L Millar
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Deirdre Khan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Matthew J Granger
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Jacob D Cavers
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Ainsley C Chan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | | | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| |
Collapse
|
15
|
Becker MG, Zhang X, Walker PL, Wan JC, Millar JL, Khan D, Granger MJ, Cavers JD, Chan AC, Fernando DWG, Belmonte MF. Transcriptome analysis of the Brassica napus-Leptosphaeria maculans pathosystem identifies receptor, signaling and structural genes underlying plant resistance. Plant J 2017. [PMID: 28222234 DOI: 10.1111/tpj/.13514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant loss of yield worldwide. While genetic resistance has been used to mitigate the disease by means of traditional breeding strategies, there is little knowledge about the genes that contribute to blackleg resistance. RNA sequencing and a streamlined bioinformatics pipeline identified unique genes and plant defense pathways specific to plant resistance in the B. napus-L. maculans LepR1-AvrLepR1 interaction over time. We complemented our temporal analyses by monitoring gene activity directly at the infection site using laser microdissection coupled to quantitative PCR. Finally, we characterized genes involved in plant resistance to blackleg in the Arabidopsis-L. maculans model pathosystem. Data reveal an accelerated activation of the plant transcriptome in resistant host cotyledons associated with transcripts coding for extracellular receptors and phytohormone signaling molecules. Functional characterization provides direct support for transcriptome data and positively identifies resistance regulators in the Brassicaceae. Spatial gradients of gene activity were identified in response to L. maculans proximal to the site of infection. This dataset provides unprecedented spatial and temporal resolution of the genes required for blackleg resistance and serves as a valuable resource for those interested in host-pathogen interactions.
Collapse
Affiliation(s)
- Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Xuehua Zhang
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Philip L Walker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Joey C Wan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Jenna L Millar
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Deirdre Khan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Matthew J Granger
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Jacob D Cavers
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Ainsley C Chan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | | | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| |
Collapse
|
16
|
Chan AC, Khan D, Girard IJ, Becker MG, Millar JL, Sytnik D, Belmonte MF. Tissue-specific laser microdissection of the Brassica napus funiculus improves gene discovery and spatial identification of biological processes. J Exp Bot 2016; 67:3561-71. [PMID: 27194740 PMCID: PMC4892738 DOI: 10.1093/jxb/erw179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The three primary tissue systems of the funiculus each undergo unique developmental programs to support the growth and development of the filial seed. To understand the underlying transcriptional mechanisms that orchestrate development of the funiculus at the globular embryonic stage of seed development, we used laser microdissection coupled with RNA-sequencing to produce a high-resolution dataset of the mRNAs present in the epidermis, cortex, and vasculature of the Brassica napus (canola) funiculus. We identified 7761 additional genes in these tissues compared with the whole funiculus organ alone using this technology. Differential expression and enrichment analyses were used to identify several biological processes associated with each tissue system. Our data show that cell wall modification and lipid metabolism are prominent in the epidermis, cell growth and modification occur in the cortex, and vascular tissue proliferation and differentiation occur in the central vascular strand. We provide further evidence that each of the three tissue systems of the globular stage funiculus are involved in specific biological processes that all co-ordinate to support seed development. The identification of genes and gene regulators responsible for tissue-specific developmental processes of the canola funiculus now serves as a valuable resource for seed improvement research.
Collapse
Affiliation(s)
- Ainsley C Chan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Deirdre Khan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Ian J Girard
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Michael G Becker
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Jenna L Millar
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - David Sytnik
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Mark F Belmonte
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
17
|
Millar JL, Khan D, Becker MG, Chan A, Dufresne A, Sumner M, Belmonte MF. Chalazal seed coat development in Brassica napus. Plant Sci 2015; 241:45-54. [PMID: 26706057 DOI: 10.1016/j.plantsci.2015.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 05/03/2023]
Abstract
The chalazal seed coat (CZSC) is a maternal subregion adjacent to the funiculus which serves as the first point of entry into the developing seed. This subregion is of particular interest in Brassica napus (canola) because of its location within the seed and its putative contribution to seed filling processes. In this study, the CZSC of canola was characterized at an anatomical and molecular level to (i) describe the cellular and subcellular features of the CZSC throughout seed development, (ii) reveal cellular features of the CZSC that relate to transport processes, (iii) study gene activity of transporters and transcriptional regulators in the CZSC subregion over developmental time, and (iv) briefly investigate the contribution of the A and C constituent genomes to B. napus CZSC gene activity. We found that the CZSC contains terminating ends of xylem and phloem as well as a mosaic of endomembrane and plasmodesmatal connections, suggesting that this subregion is likely involved in the transport of material and information from the maternal tissues of the plant to other regions of the seed. Laser microdissection coupled with quantitative RT-PCR identified the relative abundance of sugar, water, auxin and amino acid transporter homologs inherited from the constituent genomes of this complex polyploid. We also studied the expression of three transcription factors that were shown to co-express with these biological processes providing a preliminary framework for the regulatory networks responsible for seed filling in canola and discuss the relationship of the CZSC to other regions and subregions of the seed and its role in seed development.
Collapse
Affiliation(s)
- Jenna L Millar
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Deirdre Khan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Michael G Becker
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Ainsley Chan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - André Dufresne
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Michael Sumner
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Mark F Belmonte
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada.
| |
Collapse
|
18
|
Khan D, Millar JL, Girard IJ, Chan A, Kirkbride RC, Pelletier JM, Kost S, Becker MG, Yeung EC, Stasolla C, Goldberg RB, Harada JJ, Belmonte MF. Transcriptome atlas of the Arabidopsis funiculus--a study of maternal seed subregions. Plant J 2015; 82:41-53. [PMID: 0 DOI: 10.1111/tpj.12790] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/19/2015] [Accepted: 01/26/2015] [Indexed: 05/02/2023]
Abstract
The funiculus anchors the structurally complex seed to the maternal plant, and is the only direct route of transport for nutrients and maternal signals to the seed. While our understanding of seed development is becoming clearer, current understanding of the genetics and cellular mechanisms that contribute to funiculus development is limited. Using laser microdissection combined with global RNA-profiling experiments we compared the genetic profiles of all maternal and zygotic regions and subregions during seed development. We found that the funiculus is a dynamic region of the seed that is enriched for mRNAs associated with hormone metabolism, molecular transport, and metabolic activities corresponding to biological processes that have yet to be described in this maternal seed structure. We complemented our genetic data with a complete histological analysis of the funiculus from the earliest stages of development through to seed maturation at the light and electron microscopy levels. The anatomy revealed signs of photosynthesis, the endomembrane system, cellular respiration, and transport within the funiculus, all of which supported data from the transcriptional analysis. Finally, we studied the transcriptional programming of the funiculus compared to other seed subregions throughout seed development. Using newly designed in silico algorithms, we identified a number of transcriptional networks hypothesized to be responsible for biological processes like auxin response and glucosinolate biosynthesis found specifically within the funiculus. Taken together, patterns of gene activity and histological observations reveal putative functions of the understudied funiculus region and identify predictive transcriptional circuits underlying these biological processes in space and time.
Collapse
Affiliation(s)
- Deirdre Khan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Becker MG, Chan A, Mao X, Girard IJ, Lee S, Elhiti M, Stasolla C, Belmonte MF. Vitamin C deficiency improves somatic embryo development through distinct gene regulatory networks in Arabidopsis. J Exp Bot 2014; 65:5903-18. [PMID: 25151615 PMCID: PMC4203126 DOI: 10.1093/jxb/eru330] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Changes in the endogenous ascorbate redox status through genetic manipulation of cellular ascorbate levels were shown to accelerate cell proliferation during the induction phase and improve maturation of somatic embryos in Arabidopsis. Mutants defective in ascorbate biosynthesis such as vtc2-5 contained ~70 % less cellular ascorbate compared with their wild-type (WT; Columbia-0) counterparts. Depletion of cellular ascorbate accelerated cell division processes and cellular reorganization and improved the number and quality of mature somatic embryos grown in culture by 6-fold compared with WT tissues. To gain insight into the molecular mechanisms underlying somatic embryogenesis (SE), we profiled dynamic changes in the transcriptome and analysed dominant patterns of gene activity in the WT and vtc2-5 lines across the somatic embryo culturing process. Our results provide insight into the gene regulatory networks controlling SE in Arabidopsis based on the association of transcription factors with DNA sequence motifs enriched in biological processes of large co-expressed gene sets. These data provide the first detailed account of temporal changes in the somatic embryo transcriptome starting with the zygotic embryo, through tissue dedifferentiation, and ending with the mature somatic embryo, and impart insight into possible mechanisms for the improved culture of somatic embryos in the vtc2-5 mutant line.
Collapse
Affiliation(s)
- Michael G Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Ainsley Chan
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Xingyu Mao
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Ian J Girard
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Samantha Lee
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Mohamed Elhiti
- Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Egypt
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T2N2, Canada
| |
Collapse
|
20
|
Abstract
Seeds play an integral role in the global food supply and account for more than 70% of the calories that we consume on a daily basis. To meet the demands of an increasing population, scientists are turning to seed genomics research to find new and innovative ways to increase food production. Seed genomics is evolving rapidly, and the information produced from seed genomics research has exploded over the past two decades. Advances in modern sequencing strategies that profile every molecule in every cell, tissue, and organ and the emergence of new model systems have provided the tools necessary to unravel many of the biological processes underlying seed development. Despite these advances, the analyses and mining of existing seed genomics data remain a monumental task for plant biologists. This review summarizes seed region and subregion genomic data that are currently available for existing and emerging oilseed models. We provide insight into the development of tools on how to analyze large-scale datasets.
Collapse
Affiliation(s)
- Michael G. Becker
- Department of Biological Sciences, University of Manitoba, Winnipeg, MBCanada
| | - Ssu-Wei Hsu
- Department of Plant Biology, University of California Davis, Davis, CAUSA
| | - John J. Harada
- Department of Plant Biology, University of California Davis, Davis, CAUSA
| | - Mark F. Belmonte
- Department of Biological Sciences, University of Manitoba, Winnipeg, MBCanada
- *Correspondence: Mark F. Belmonte, Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada e-mail:
| |
Collapse
|
21
|
Becker MG, Barth RP. Power through choices: the development of a sexuality education curriculum for youths in out-of-home care. Child Welfare 2000; 79:269-282. [PMID: 10813084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Youths in out-of-home care demonstrate high rates of sexual risk-taking behavior and elevated rates of unintended pregnancy and sexually transmitted infections (STIs). This article profiles the development and characteristics of an innovative pregnancy/HIV/STI prevention curriculum tailored to the needs of youths in out-of-home care. Promising results from an implementation study suggest the need for further dissemination and rigorous testing.
Collapse
Affiliation(s)
- M G Becker
- Jordan Institute for Families, University of North Carolina School of Social Work, Chapel Hill, USA
| | | |
Collapse
|