1
|
Guo X, Li R, Ding Y, Mo F, Hu K, Ou M, Jiang D, Li M. Visualization of the Infection and Colonization Process of Dendrobium officinale Using a Green Fluorescent Protein-Tagged Isolate of Fusarium oxysporum. PHYTOPATHOLOGY 2024; 114:1791-1801. [PMID: 38809697 DOI: 10.1094/phyto-12-23-0495-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Dendrobium officinale soft rot is a widespread and destructive disease caused by Fusarium oxysporum that can seriously affect yield and quality. To better understand the fungal infection and colonization, we successfully created an F. oxysporum labeled with green fluorescent protein using the Agrobacterium tumefaciens-mediated transformation method. Transformants had varying fluorescence intensities, but their pathogenicity did not differ from that of the wild type. Fluorescence microscopy revealed that F. oxysporum primarily entered the aboveground portion of D. officinale through the leaf margin, stomata, or by direct penetration of the leaf surface. It then colonized the mesophyll and spread along its vascular bundles. D. officinale exhibited typical symptoms of decay and wilting at 14 days postinoculation, accompanied by a pronounced fluorescence signal in the affected area. The initial colonization of F. oxysporum in the subterranean region primarily involved attachment to the root hair and epidermis, which progressed to the medullary vascular bundle. At 14 days postinoculation, the root vascular bundles of D. officinale exhibited significant colonization by F. oxysporum. Macroconidia were also observed in black rot D. officinale tissue. In particular, the entire root was surrounded by a significant number of chlamydospore-producing F. oxysporum mycelia at 28 days postinoculation. This approach allowed for the visualization of the complete infection process of F. oxysporum and provided a theoretical foundation for the development of field control strategies.
Collapse
Affiliation(s)
- Xue Guo
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Rongyu Li
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
- The Provincial Key Laboratory for Agricultural Pest Management in Mountainous Region, Guiyang, Guizhou 550025, China
| | - Yi Ding
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Feixu Mo
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Ke Hu
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Minggui Ou
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Diao Jiang
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
| | - Ming Li
- Institute of Crop Protection, Guizhou University, Guiyang, Guizhou 550025, China
- College of Agriculture, Guizhou University, Guiyang, Guizhou 550025, China
- The Provincial Key Laboratory for Agricultural Pest Management in Mountainous Region, Guiyang, Guizhou 550025, China
| |
Collapse
|
2
|
Bhagat N, Magotra S, Gupta R, Sharma S, Verma S, Verma PK, Ali T, Shree A, Vakhlu J. Invasion and Colonization of Pathogenic Fusarium oxysporum R1 in Crocus sativus L. during Corm Rot Disease Progression. J Fungi (Basel) 2022; 8:1246. [PMID: 36547579 PMCID: PMC9784501 DOI: 10.3390/jof8121246] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 11/29/2022] Open
Abstract
The corm rot of saffron caused by Fusarium oxysporum (Fox) has been reported to be the most destructive fungal disease of the herb globally. The pathogen, Fusarium oxysporum R1 (Fox R1) isolated by our group from Kashmir, India, was found to be different from Fusarium oxysporum f.sp. gladioli commonly reported corm rot agent of saffron. In the present study, Fox R1 was further characterized using housekeeping genes and pathogenicity tests, as Fusarium oxysporum R1 f.sp. iridacearum race 4. Though Fox R1 invaded the saffron plant through both corm and roots, the corm was found to be the preferred site of infection. In addition, the route of pathogen movement wastracked by monitoring visual symptoms, semi-quantitative PCR, quantitative-PCR (q-PCR), real-time imaging of egfp-tagged Fusarium oxysporum R1, and Fox R1 load quantification. This study is the first study of its kind on the bidirectional pathogenesis from corm to roots and vice-versa, as the literature only reports unidirectional upward movement from roots to other parts of the plant. In addition, the colonization pattern of Fox R1 in saffron corms and roots was studied. The present study involved a systematic elucidation of the mode and mechanism of pathogenesis in the saffron Fusarium oxysporum strain R1 pathosystem.
Collapse
Affiliation(s)
- Nancy Bhagat
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
| | - Shanu Magotra
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
- University Institute of Biotechnology, Chandigarh University, Ajitgarh 140413, India
| | - Rikita Gupta
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
| | - Shikha Sharma
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
| | - Sandhya Verma
- Plant Immunity Laboratory, National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
| | - Praveen Kumar Verma
- Plant Immunity Laboratory, National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Tahir Ali
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
| | - Ankita Shree
- Plant Immunity Laboratory, National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
| | - Jyoti Vakhlu
- Metagenomic Laboratory, School of Biotechnology, University of Jammu, Jammu 180006, India
| |
Collapse
|
3
|
Agisha VN, Ashwin NMR, Vinodhini RT, Nalayeni K, Ramesh Sundar A, Malathi P, Viswanathan R. Protoplast-mediated transformation in Sporisorium scitamineum facilitates visualization of in planta developmental stages in sugarcane. Mol Biol Rep 2021; 48:7921-7932. [PMID: 34655406 DOI: 10.1007/s11033-021-06823-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/08/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Sporisorium scitamineum is the causative agent of smut disease in sugarcane. The tricky life cycle of S. scitamineum consists of three distinct growth stages: diploid teliospores, haploid sporidia and dikaryotic mycelia. Compatible haploid sporidia representing opposite mating types (MAT-1 and MAT-2) of the fungus fuse to form infective dikaryotic mycelia in the host tissues, leading to the development of a characteristic whip shaped sorus. In this study, the transition of distinct stages of in vitro life cycle and in planta developmental stages of S. scitamineum are presented by generating stable GFP transformants of S. scitamineum. METHODS AND RESULTS Haploid sporidia were isolated from the teliospores of Ss97009, and the opposite mating types (MAT-1 and MAT-2) were identified by random mating assay and mating type-specific PCR. Both haploid sporidia were individually transformed with pNIIST plasmid, harboring an enhanced green fluorescent protein (eGFP) gene and hygromycin gene by a modified protoplast-based PEG-mediated transformation method. Thereafter, the distinct in vitro developmental stages including fusion of haploid sporidia and formation of dikaryotic mycelia expressing GFP were demonstrated. To visualize in planta colonization, transformed haploids (MAT-1gfp and MAT-2gfp) were fused and inoculated onto the smut susceptible sugarcane cultivar, Co 97009 and examined microscopically at different stages of colonization. GFP fluorescence-based analysis presented an extensive fungal colonization of the bud surface as well as inter- and intracellular colonization of the transformed S. scitamineum in sugarcane tissues during initial stages of disease development. Noticeably, the GFP-tagged S. scitamineum led to the emergence of smut whips, which established their pathogenicity, and demonstrated initial colonization, active sporogenesis and teliospore maturation stages. CONCLUSION Overall, for the first time, an efficient protoplast-based transformation method was employed to depict clear-cut developmental stages in vitro and in planta using GFP-tagged strains for better understanding of S. scitamineum life cycle development.
Collapse
Affiliation(s)
- V N Agisha
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| | - N M R Ashwin
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| | - R T Vinodhini
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| | - Kumaravel Nalayeni
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| | - Amalraj Ramesh Sundar
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India.
| | - Palaniyandi Malathi
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| | - Rasappa Viswanathan
- Plant Pathology Section, Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India
| |
Collapse
|
4
|
Nabi A, Banoo A, Rasool RS, Dar MS, Mubashir SS, Masoodi KZ, Shah MD, Khan AA, Khan I, Padder BA. Optimizing the Agrobacterium tumifaciens mediated transformation conditions in Colletotrichum lindemuthianum: A step forward to unravel the functions of pathogenicity arsenals. Lett Appl Microbiol 2021; 75:293-307. [PMID: 34398478 DOI: 10.1111/lam.13552] [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] [Received: 12/30/2020] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/28/2022]
Abstract
Colletotrichum lindemuthianum is a hemibiotrophic fungal pathogen that causes bean anthracnose and it is rated among the top 10 important diseases infecting beans. Currently our knowledge on molecular mechanisms underlying C. lindemuthianum pathogenesis is limited. About five pathogenicity genes have been identified in C. lindemuthianum using Restricted Enzyme Mediated Integration (REMI) and the transformation using Agroinfection has not been optimized. In this study, a series of experiments were conducted to optimize the key parameters affecting the Agrobacterium tumefaciens- mediated transformation (ATMT) for C. lindemuthianum. The transformation efficiency increased with increase in spore concentration and co-cultivation time. However, the optimum conditions that yielded significant number of transformants were 106 ml-1 spore concentration, co-cultivation time of 72 h, incubation at 25ºC and using a cellulose membrane filter for the co-cultivation. The optimized protocol resulted in establishment of large mutant library (2400). A few mutants were melanin deficient and a few were unable to produce conidia. To determine the altered pathogenicity, two new approaches such as detached leaf and twig techniques proved reliable and require fewer resources to screen the large mutant libraries in a short time. Among the 1200 transformants tested for virulence, 90% transformants were pathogenically similar to wild type (race 2047), 96 and 24 were reduced and impaired, respectively. The altered avirulent transformants can prove vital for understanding the missing link between growth and developmental stages of pathogen with virulence. This platform will help to develop strategies to determine the potential pathogenicity genes and to decipher molecular mechanisms of host-pathogen interactions in more detail.
Collapse
Affiliation(s)
- Aasiya Nabi
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Aqleema Banoo
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Rovidha S Rasool
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - M S Dar
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Syed Shoaib Mubashir
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Khalid Z Masoodi
- Division of Plant Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - M D Shah
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Akhtar A Khan
- Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Imran Khan
- Division of Agricultural Statistics, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| | - Bilal A Padder
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, India, 190 025
| |
Collapse
|
5
|
Shen Y, Nie J, Kuang L, Zhang J, Li H. DNA sequencing, genomes and genetic markers of microbes on fruits and vegetables. Microb Biotechnol 2020; 14:323-362. [PMID: 32207561 PMCID: PMC7936329 DOI: 10.1111/1751-7915.13560] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/20/2022] Open
Abstract
The development of DNA sequencing technology has provided an effective method for studying foodborne and phytopathogenic microorganisms on fruits and vegetables (F & V). DNA sequencing has successfully proceeded through three generations, including the tens of operating platforms. These advances have significantly promoted microbial whole‐genome sequencing (WGS) and DNA polymorphism research. Based on genomic and regional polymorphisms, genetic markers have been widely obtained. These molecular markers are used as targets for PCR or chip analyses to detect microbes at the genetic level. Furthermore, metagenomic analyses conducted by sequencing the hypervariable regions of ribosomal DNA (rDNA) have revealed comprehensive microbial communities in various studies on F & V. This review highlights the basic principles of three generations of DNA sequencing, and summarizes the WGS studies of and available DNA markers for major bacterial foodborne pathogens and phytopathogenic fungi found on F & V. In addition, rDNA sequencing‐based bacterial and fungal metagenomics are summarized under three topics. These findings deepen the understanding of DNA sequencing and its application in studies of foodborne and phytopathogenic microbes and shed light on strategies for the monitoring of F & V microbes and quality control.
Collapse
Affiliation(s)
- Youming Shen
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Jiyun Nie
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China.,College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lixue Kuang
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Jianyi Zhang
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Haifei Li
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| |
Collapse
|
6
|
Thyrostroma carpophilum insertional mutagenesis: A step towards understanding its pathogenicity mechanism. J Microbiol Methods 2020; 171:105885. [PMID: 32147575 DOI: 10.1016/j.mimet.2020.105885] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 11/24/2022]
Abstract
Thyrostroma carpophilum, a causal agent of shot hole disease of stone fruits, cause severe loss in economically important fruit crops of Kashmir. Understanding its pathogenesis at molecular level will aid in devising a better management strategy. In this study, we optimized Agrobacterium tumefaciens mediated transformation (ATMT) conditions for T. carpophilum using PBIF2-EGFP construct. Using this protocol, we obtained 328 positive transformants per 104 spores and subsequent sub-culturing of transformants on selective and non-selective media resulted in stable T-DNA integration. Southern blot analysis revealed that most of the transformants embodied single T-DNA integration. Using this method, we obtained a small-scale transformant library (2050 transformants). Among this pool, we tested 1005 transformants for their pathogenicity; out of which 185 showed complete pathogenicity loss, 35 displayed reduced virulence and 785 were pathogenically similar to wild type. Out of this experimental stock, three transformants from each category were randomly selected to dissect the infection assay. The findings deciphered that transformants with complete pathogenicity loss failed to penetrate the host tissue and a few transformants failed to sporulate in laboratory. Transformants from reduced category could not form appressorium and occasionally sporulated. Transformants similar to wild type were morphologically and pathogenically similar to wild type because of un-alteration in their modus operandi. Our work provides a new platform to understand the pathogenicity mechanism of T. carpophilum. The optimized ATMT protocol will help in developing large transformant library that can help to identify the virulence arsenals necessary for the pathogen to cause disease.
Collapse
|
7
|
Agrobacterium tumefaciens-mediated transformation and expression of GFP in Ascochyta lentis to characterize ascochyta blight disease progression in lentil. PLoS One 2019; 14:e0223419. [PMID: 31647840 PMCID: PMC6812748 DOI: 10.1371/journal.pone.0223419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/20/2019] [Indexed: 11/25/2022] Open
Abstract
The plant immune system is made up of a complex response network that involves several lines of defense to fight invading pathogens. Fungal plant pathogens on the other hand, have evolved a range of ways to infect their host. The interaction between Ascochyta lentis and two lentil genotypes was explored to investigate the progression of ascochyta blight (AB) in lentils. In this study, we developed an Agrobacterium tumefaciens-mediated transformation system for A. lentis by constructing a new binary vector, pATMT-GpdGFP, for the constitutive expression of green fluorescent protein (EGFP). Green fluorescence was used as a highly efficient vital marker to study the developmental changes in A. lentis during AB disease progression on the susceptible and resistant lentil accessions, ILL6002 and ILL7537, respectively. The initial infection stages were similar in both the resistant and susceptible accessions where A. lentis uses infection structures such as germ tubes and appressoria to gain entry into the host while the host uses defense mechanisms to prevent pathogen entry. Penetration was observed at the junctions between neighbouring epidermal cells and occasionally, through the stomata. The pathogen attempted to penetrate and colonize ILL7537, but further fungal advancement appeared to be halted, and A. lentis did not enter the mesophyll. Successful entry and colonization of ILL6002 coincided with structural changes in A. lentis and the onset of necrotic lesions 5–7 days post inoculation. Once inside the leaf, A. lentis continued to grow, colonizing all parts of the leaf followed by plant cell collapse. Pycnidia-bearing spores appeared 14 days post inoculation, which marks the completion of the infection cycle. The use of fluorescent proteins in plant pathogenic fungi together with confocal laser scanning microscopy, provide a valuable tool to study the intracellular dynamics, colonization strategy and infection mechanisms during plant-pathogen interaction.
Collapse
|
8
|
Agrobacterium-Mediated Transformation of Diaporthe schini Endophytes Associated with Vitis labrusca L. and Its Antagonistic Activity Against Grapevine Phytopathogens. Indian J Microbiol 2019; 59:217-224. [PMID: 31031437 DOI: 10.1007/s12088-019-00787-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/19/2019] [Indexed: 10/27/2022] Open
Abstract
Fungus-caused diseases are among the greatest losses in grapevine culture. Biological control of pathogens by endophytes may be used to decrease fungicide application rates and environmental impacts. Previously, Diaporthe sp. B46-64 and C27-07 were highlighted as antagonists of grapevine phytopathogens. Herein, molecular multigene (ITS-TUB-TEF1) identification and phylogenetic analysis allowed the identification of these endophytes as belonging to Diaporthe schini species. Agrobacterium tumefaciens-mediated transformation was employed for obtaining 14 stable and traceable gfp- or DsRed-expressing transformants, with high transformation efficiency: 96% for the pFAT-GFP plasmid and 98% for pCAM-DsRed plasmid. Transformants were resistant to hygromycin B with gene hph confirmed by polymerase chain reaction and proved to be mitotically stable, expressing the fluorescent phenotype, with morphological differences in the colonies when compared with wild strains. In vitro antagonism tests revealed an increased antagonistic activity of some transformant strains. The current genetic transformation of D. schini mediated by A. tumefaciens proved to be an efficient technique within the randomized insertion of reporter genes for the monitoring of the strain in the environment.
Collapse
|
9
|
Ochoa JC, Herrera M, Navia M, Romero HM. Visualization of Phytophthora palmivora Infection in Oil Palm Leaflets with Fluorescent Proteins and Cell Viability Markers. THE PLANT PATHOLOGY JOURNAL 2019; 35:19-31. [PMID: 30828276 PMCID: PMC6385658 DOI: 10.5423/ppj.oa.02.2018.0034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/17/2018] [Accepted: 08/21/2018] [Indexed: 06/09/2023]
Abstract
Bud rot (BR) is the most devastating disease affecting oil palm (Elaeis guineensis) crops in Colombia. Its causal agent, Phytophthora palmivora, initiates the infection in immature oil palm leaflets producing necrotic lesions, followed by colonization of opportunistic necrotrophs, which increases disease damage. To improve the characterization of the disease, we transformed P. palmivora using Agrobacterium tumefaciens-mediated transformation (ATMT) to include the fluorescent proteins CFP-SKL (peroxisomal localization), eGFP and mRFP1 (cytoplasmic localization). The stability of some transformants was confirmed by Southern blot analysis and single zoospore cultures; additionally, virulence and in vitro growth were compared to the wild-type isolate to select transformants with the greatest resemblance to the WT isolate. GFP-tagged P. palmivora was useful to identify all of the infective structures that are commonly formed by hemibiotrophic oomycetes, including apoplastic colonization and haustorium formation. Finally, we detected cell death responses associated with immature oil palm tissues that showed reduced susceptibility to P. palmivora infection, indicating that these tissues could exhibit age-related resistance. The aim of this research is to improve the characterization of the initial disease stages and generate cell biology tools that may be useful for developing methodologies for early identification of oil palm materials resistant or susceptible to BR.
Collapse
Affiliation(s)
- Juan C. Ochoa
- Oil Palm Biology and Breeding Research Program, Colombian Oil Palm Research Center (CENIPALMA), Bogotá,
Colombia
| | - Mariana Herrera
- Oil Palm Biology and Breeding Research Program, Colombian Oil Palm Research Center (CENIPALMA), Bogotá,
Colombia
| | - Mónica Navia
- Oil Palm Biology and Breeding Research Program, Colombian Oil Palm Research Center (CENIPALMA), Bogotá,
Colombia
| | - Hernán Mauricio Romero
- Oil Palm Biology and Breeding Research Program, Colombian Oil Palm Research Center (CENIPALMA), Bogotá,
Colombia
- Departamento de Biología, Universidad Nacional de Colombia, Bogotá,
Colombia
| |
Collapse
|
10
|
Su X, Lu G, Rehman L, Li X, Sun L, Guo H, Cheng H. mCherry-Labeled Verticillium dahliae Could Be Utilized to Investigate Its Pathogenicity Process in Nicotiana benthamiana. Genes (Basel) 2018; 9:E508. [PMID: 30340423 PMCID: PMC6210675 DOI: 10.3390/genes9100508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/13/2018] [Accepted: 10/16/2018] [Indexed: 11/16/2022] Open
Abstract
Verticillium dahliae is a soil-borne phytopathogenic fungus that causes a destructive vascular wilt, but details of the molecular mechanism behind its pathogenicity are not very clear. Here, we generated a red fluorescent isolate of V. dahliae by protoplast transformation to explore its pathogenicity mechanism, including colonization, invasion, and extension in Nicotiana benthamiana, using confocal microscopy. The nucleotide sequences of mCherry were optimized for fungal expression and cloned into pCT-HM plasmid, which was inserted into V. dahliae protoplasts. The transformant (Vd-m) shows strong red fluorescence and its phenotype, growth rate, and pathogenicity did not differ significantly from the wild type V. dahliae (Vd-wt). Between one and three days post inoculation (dpi), the Vd-m successfully colonized and invaded epidermal cells of the roots. From four to six dpi, hyphae grew on root wounds and lateral root primordium and entered xylem vessels. From seven to nine dpi, hyphae extended along the surface of the cell wall and massively grew in the xylem vessel of roots. At ten dpi, the Vd-m was found in petioles and veins of leaves. Our results distinctly showed the pathway of V. dahliae infection and colonization in N. benthamiana, and the optimized expression can be used to deepen our understanding of the molecular mechanism of pathogenicity.
Collapse
Affiliation(s)
- Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Guoqing Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Latifur Rehman
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
- Department of Biotechnology, The University of Swabi, Khyber Pakhtunkhwa 23561, Pakistan.
| | - Xiaokang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Lu Sun
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
- College of Life Engineering, Shenyang Institute of Technology, Fushun 113122, China.
| | - Huiming Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Hongmei Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| |
Collapse
|
11
|
A highly efficient Agrobacterium tumefaciens-mediated transformation system for the postharvest pathogen Penicillium digitatum using DsRed and GFP to visualize citrus host colonization. J Microbiol Methods 2017; 144:134-144. [PMID: 29175534 DOI: 10.1016/j.mimet.2017.11.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/21/2017] [Accepted: 11/21/2017] [Indexed: 11/21/2022]
Abstract
Penicillium digitatum is a major postharvest pathogen of citrus crops. This fungus broadly spreads worldwide and causes green mold disease, which results in severe losses for citrus production. Understanding of the citrus infection by P. digitatum may help develop effective strategies for controlling this pathogen. In this study, we have characterized a virulent strain of P. digitatum isolated in Vietnam and established a highly efficient Agrobacterium tumefaciens-mediated transformation (ATMT) system for this fungal strain with two newly constructed binary vectors. These binary vectors harbor dominant selectable markers for hygromycin or nourseothricin resistance, and expression cassettes for the red fluorescent protein (DsRed) or the green fluorescent protein (GFP), respectively. Using the established ATMT system, the transformation efficiency of the Vietnamese strain could reach a very high yield of 1240±165 transformants per 106 spores. Interestingly, we found that GFP is much better than DsRed for in situ visualization of citrus fruit colonization by the fungus. Additionally, we showed that the transformation system can also be used to generate T-DNA insertion mutants for screening non-pathogenic or less virulent strains. Our work provides a new platform including a virulent tropical strain of P. digitatum, an optimized ATMT method and two newly constructed binary vectors for investigation of the postharvest pathogen. This platform will help develop strategies to dissect molecular mechanisms of host-pathogen interactions in more detail as well as to identify potential genes of pathogenicity by either insertional mutagenesis or gene disruption in this important pathogenic fungus.
Collapse
|