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Ali A, Shahbaz M, Ölmez F, Fatima N, Umar UUD, Ali MA, Akram M, Seelan JSS, Baloch FS. RNA interference: a promising biotechnological approach to combat plant pathogens, mechanism and future prospects. World J Microbiol Biotechnol 2024; 40:339. [PMID: 39358476 DOI: 10.1007/s11274-024-04143-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Accepted: 09/13/2024] [Indexed: 10/04/2024]
Abstract
Plant pathogens and other biological pests represent significant obstacles to crop Protection worldwide. Even though there are many effective conventional methods for controlling plant diseases, new methods that are also effective, environmentally safe, and cost-effective are required. While plant breeding has traditionally been used to manipulate the plant genome to develop resistant cultivars for controlling plant diseases, the emergence of genetic engineering has introduced a completely new approach to render plants resistant to bacteria, nematodes, fungi, and viruses. The RNA interference (RNAi) approach has recently emerged as a potentially useful tool for mitigating the inherent risks associated with the development of conventional transgenics. These risks include the use of specific transgenes, gene control sequences, or marker genes. Utilizing RNAi to silence certain genes is a promising solution to this dilemma as disease-resistant transgenic plants can be generated within a legislative structure. Recent investigations have shown that using target double stranded RNAs via an effective vector system can produce significant silencing effects. Both dsRNA-containing crop sprays and transgenic plants carrying RNAi vectors have proven effective in controlling plant diseases that threaten commercially significant crop species. This article discusses the methods and applications of the most recent RNAi technology for reducing plant diseases to ensure sustainable agricultural yields.
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Affiliation(s)
- Amjad Ali
- Department of Plant Protection, Faculty of Agricultural Sciences and Technologies, Sivas University of Science and Technology, 58140, Sivas, Turkey
| | - Muhammad Shahbaz
- Institute for Tropical Biology and Conservation (ITBC), Universiti Malaysia Sabah, Jalan UMS, 88400, Kota kinabalu, Malaysia
| | - Fatih Ölmez
- Department of Plant Protection, Faculty of Agricultural Sciences and Technologies, Sivas University of Science and Technology, 58140, Sivas, Turkey
| | - Noor Fatima
- Department of Botany, Lahore College for Women University, 54000, Lahore, Punjab, Pakistan
| | - Ummad Ud Din Umar
- Department of Plant Pathology, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Main Campus, Bosan Road, 60800, Multan, Pakistan
| | - Md Arshad Ali
- Biotechnology Program, Faculty of Science and Natural, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Muhammad Akram
- Department of Botany, The Islamia University of Bahawalpur, 63100, Bahawalpur, Punjab, Pakistan
| | - Jaya Seelan Sathiya Seelan
- Institute for Tropical Biology and Conservation (ITBC), Universiti Malaysia Sabah, Jalan UMS, 88400, Kota kinabalu, Malaysia.
| | - Faheem Shehzad Baloch
- Department of Biotechnology, Faculty of Science, Mersin University, 33343, Yenişehir Mersin, Turkey.
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Liu C, Kogel K, Ladera‐Carmona M. Harnessing RNA interference for the control of Fusarium species: A critical review. MOLECULAR PLANT PATHOLOGY 2024; 25:e70011. [PMID: 39363756 PMCID: PMC11450251 DOI: 10.1111/mpp.70011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 08/13/2024] [Accepted: 09/10/2024] [Indexed: 10/05/2024]
Abstract
Fusarium fungi are a pervasive threat to global agricultural productivity. They cause a spectrum of plant diseases that result in significant yield losses and threaten food safety by producing mycotoxins that are harmful to human and animal health. In recent years, the exploitation of the RNA interference (RNAi) mechanism has emerged as a promising avenue for the control of Fusarium-induced diseases, providing both a mechanistic understanding of Fusarium gene function and a potential strategy for environmentally sustainable disease management. However, despite significant progress in elucidating the presence and function of the RNAi pathway in different Fusarium species, a comprehensive understanding of its individual protein components and underlying silencing mechanisms remains elusive. Accordingly, while a considerable number of RNAi-based approaches to Fusarium control have been developed and many reports of RNAi applications in Fusarium control under laboratory conditions have been published, the applicability of this knowledge in agronomic settings remains an open question, and few convincing data on RNAi-based disease control under field conditions have been published. This review aims to consolidate the current knowledge on the role of RNAi in Fusarium disease control by evaluating current research and highlighting important avenues for future investigation.
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Affiliation(s)
- Caihong Liu
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and NutritionJustus Liebig University GiessenGiessenGermany
| | - Karl‐Heinz Kogel
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and NutritionJustus Liebig University GiessenGiessenGermany
- Institut de Biologie Moléculaire des Plantes, CNRSUniversité de StrasbourgStrasbourgFrance
| | - Maria Ladera‐Carmona
- Institute of Phytopathology, Research Centre for BioSystems, Land Use and NutritionJustus Liebig University GiessenGiessenGermany
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Yu X, Lin X, Zhou T, Cao L, Hu K, Li F, Qu S. Host-induced gene silencing in wild apple germplasm Malus hupehensis confers resistance to the fungal pathogen Botryosphaeria dothidea. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:1174-1193. [PMID: 38430515 DOI: 10.1111/tpj.16664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 12/24/2023] [Accepted: 01/22/2024] [Indexed: 03/04/2024]
Abstract
Host-induced gene silencing (HIGS) is an inherent mechanism of plant resistance to fungal pathogens, resulting from cross-kingdom RNA interference (RNAi) mediated by small RNAs (sRNAs) delivered from plants into invading fungi. Introducing artificial sRNA precursors into crops can trigger HIGS of selected fungal genes, and thus has potential applications in agricultural disease control. To investigate the HIGS of apple (Malus sp.) during the interaction with Botryosphaeria dothidea, the pathogenic fungus causing apple ring rot disease, we evaluated whether apple miRNAs can be transported into and target genes in B. dothidea. Indeed, miR159a from Malus hupehensis, a wild apple germplasm with B. dothidea resistance, silenced the fungal sugar transporter gene BdSTP. The accumulation of miR159a in extracellular vesicles (EVs) of both infected M. hupehensis and invading B. dothidea suggests that this miRNA of the host is transported into the fungus via the EV pathway. Knockout of BdSTP caused defects in fungal growth and proliferation, whereas knockin of a miR159a-insensitive version of BdSTP resulted in increased pathogenicity. Inhibition of miR159a in M. hupehensis substantially enhanced plant sensitivity to B. dothidea, indicating miR159a-mediated HIGS against BdSTP being integral to apple immunity. Introducing artificial sRNA precursors targeting BdSTP and BdALS, an acetolactate synthase gene, into M. hupehensis revealed that double-stranded RNAs were more potent than engineered MIRNAs in triggering HIGS alternative to those natural of apple and inhibiting infection. These results provide preliminary evidence for cross-kingdom RNAi in the apple-B. dothidea interaction and establish HIGS as a potential disease control strategy in apple.
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Affiliation(s)
- Xinyi Yu
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Xinxin Lin
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Tingting Zhou
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Lifang Cao
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Kaixu Hu
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Fangzhu Li
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
| | - Shenchun Qu
- College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, P.R. China
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Xu Y, Tan J, Lu J, Zhang Y, Li X. RAS signalling genes can be used as host-induced gene silencing targets to control fungal diseases caused by Sclerotinia sclerotiorum and Botrytis cinerea. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:262-277. [PMID: 37845842 PMCID: PMC10754012 DOI: 10.1111/pbi.14184] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 08/27/2023] [Accepted: 09/02/2023] [Indexed: 10/18/2023]
Abstract
Sclerotinia sclerotiorum causes white mold (also called stem rot, Sclerotinia blight, etc.) in many economically important plants. It is a notorious soilborne fungal pathogen due to its wide host range and ability to survive in soil for long periods of time as sclerotia. Although host-induced gene silencing (HIGS) was recently demonstrated to be an effective method for controlling white mold, limited gene targets are available. Here, using a forward genetics approach, we identified a RAS-GTPase activating protein, SsGAP1, which plays essential roles in sclerotia formation, compound appressoria production and virulence. In parallel, as revealed by our knockout analysis, the SsGAP1 ortholog in Botrytis cinerea, BcGAP1, plays similar roles in fungal development and virulence. By knocking down SsRAS1 and SsRAS2, we also revealed that both SsRAS1 and SsRAS2 are required for vegetative growth, sclerotia development, compound appressoria production and virulence in S. sclerotiorum. Due to the major roles these RAS signalling components play in Sclerotiniaceae biology, they can be used as HIGS targets to control diseases caused by both S. sclerotiorum and B. cinerea. Indeed, when we introduced HIGS constructs targeting SsGAP1, SsRAS1 and SsRAS2 in Nicotiana benthamiana and Arabidopsis thaliana, we observed reduced virulence. Taken together, our forward genetics gene discovery pipeline in S. sclerotiorum is highly effective in identifying novel HIGS targets to control S. sclerotiorum and B. cinerea.
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Affiliation(s)
- Yan Xu
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Jinyi Tan
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Junxing Lu
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- College of Life ScienceChongqing Normal UniversityChongqingChina
| | - Yuelin Zhang
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Xin Li
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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Xu Y, Qiu Y, Zhang Y, Li X. A cAMP phosphodiesterase is essential for sclerotia formation and virulence in Sclerotinia sclerotiorum. FRONTIERS IN PLANT SCIENCE 2023; 14:1175552. [PMID: 37324679 PMCID: PMC10264682 DOI: 10.3389/fpls.2023.1175552] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
Sclerotinia sclerotiorum is a plant pathogenic fungus that causes white mold or stem rot diseases. It affects mostly dicotyledonous crops, resulting in significant economic losses worldwide. Sclerotia formation is a special feature of S. sclerotiorum, allowing its survival in soil for extended periods and facilitates the spread of the pathogen. However, the detailed molecular mechanisms of how sclerotia are formed and how virulence is achieved in S. sclerotiorum are not fully understood. Here, we report the identification of a mutant that cannot form sclerotia using a forward genetics approach. Next-generation sequencing of the mutant's whole genome revealed candidate genes. Through knockout experiments, the causal gene was found to encode a cAMP phosphodiesterase (SsPDE2). From mutant phenotypic examinations, we found that SsPDE2 plays essential roles not only in sclerotia formation, but also in the regulation of oxalic acid accumulation, infection cushion functionality and virulence. Downregulation of SsSMK1 transcripts in Sspde2 mutants revealed that these morphological defects are likely caused by cAMP-dependent inhibition of MAPK signaling. Moreover, when we introduced HIGS construct targeting SsPDE2 in Nicotiana benthamiana, largely compromised virulence was observed against S. sclerotiorum. Taken together, SsPDE2 is indispensable for key biological processes of S. sclerotiorum and can potentially serve as a HIGS target to control stem rot in the field.
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Affiliation(s)
- Yan Xu
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Yilan Qiu
- Department of Life Science, Hunan Normal University, Changsha, China
| | - Yuelin Zhang
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Xin Li
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
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Raruang Y, Omolehin O, Hu D, Wei Q, Promyou S, Parekattil LJ, Rajasekaran K, Cary JW, Wang K, Chen ZY. Targeting the Aspergillus flavus p2c gene through host-induced gene silencing reduces A. flavus infection and aflatoxin contamination in transgenic maize. FRONTIERS IN PLANT SCIENCE 2023; 14:1150086. [PMID: 37229129 PMCID: PMC10203651 DOI: 10.3389/fpls.2023.1150086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/11/2023] [Indexed: 05/27/2023]
Abstract
Aspergillus flavus is an opportunistic fungal pathogen that infects maize and produces aflatoxins. Using biocontrol or developing resistant cultivars to reduce aflatoxin contamination has only achieved limited success. Here, the A. flavus polygalacturonase gene (p2c) was targeted for suppression through host-induced gene silencing (HIGS) to reduce aflatoxin contamination in maize. An RNAi vector carrying a portion of the p2c gene was constructed and transformed into maize B104. Thirteen out of fifteen independent transformation events were confirmed to contain p2c. The T2 generation kernels containing the p2c transgene had less aflatoxin than those without the transgene in six out of eleven events we examined. Homozygous T3 transgenic kernels from four events produced significantly less aflatoxins (P ≤ 0.02) than the kernels from the null or B104 controls under field inoculation conditions. The F1 kernels from the crosses between six elite inbred lines with P2c5 and P2c13 also supported significantly less aflatoxins (P ≤ 0.02) than those from the crosses with null plants. The reduction in aflatoxin ranged from 93.7% to 30.3%. Transgenic leaf (T0 and T3) and kernel tissues (T4) were also found to have significantly higher levels of p2c gene-specific small RNAs. Further, homozygous transgenic maize kernels had significantly less fungal growth (27~40 fold) than the null control kernels 10 days after fungal inoculation in the field. The calculated suppression of p2c gene expression based on RNAseq data was 57.6% and 83.0% in P2c5 and P2c13 events, respectively. These results indicate clearly that the reduced aflatoxin production in the transgenic kernels is due to RNAi-based suppression of p2c expression, which results in reduced fungal growth and toxin production.
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Affiliation(s)
- Yenjit Raruang
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Olanike Omolehin
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Dongfang Hu
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Qijian Wei
- Food and Feed Safety Research Unit, United States Department of Agriculture – Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Surassawadee Promyou
- Faculty of Natural Resources and Agro-Industry, Kasetsart University, Sakonnakhon, Thailand
| | - Lidiya J. Parekattil
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, United States Department of Agriculture – Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Jeffrey W. Cary
- Food and Feed Safety Research Unit, United States Department of Agriculture – Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Kan Wang
- Department of Agronomy, Iowa State University, Ames, IA, United States
| | - Zhi-Yuan Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
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Xu J, Zhang N, Wang K, Xian Q, Dong J, Chen X. Exploring new strategies in diseases resistance of horticultural crops. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.1021350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Horticultural crops are susceptible to various biotic stressors including fungi, oomycetes, bacteria, viruses, and root-knot nematodes. These pathogens limit the growth, development, yield, and quality of horticultural crops, and also limit their adaptability and geographic distribution. The continuous cropping model in horticultural facilities exacerbates soil-borne diseases, and severely restricts yield, quality, and productivity. Recent progress in the understanding of mechanisms that confer tolerance to different diseases through innovative strategies including host-induced gene silencing (HIGS), targeting susceptibility genes, and rootstocks grafting applications are reviewed to systematically explore the resistance mechanisms against horticultural plant diseases. Future work should successfully breed resistant varieties using these strategies combined with molecular biologic methods.
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Host-induced gene silencing of PcCesA3 and PcOSBP1 confers resistance to Phytophthora capsici in Nicotiana benthamiana through NbDCL3 and NbDCL4 processed small interfering RNAs. Int J Biol Macromol 2022; 222:1665-1675. [PMID: 36167102 DOI: 10.1016/j.ijbiomac.2022.09.178] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/24/2022]
Abstract
Host-induced gene silencing (HIGS) is a RNA-based system depend on the biological macromolecules generated in plants to control diseases. However, the effector proteins active in the HIGS are uncertain, which impedes its further application, especially for oomycete that lack efficient HIGS targets. Phytophthora capsici is an important oomycete causes blight in over 70 crops. Here, we comprehensively screened efficient HIGS vectors targeting PcCesA3 or PcOSBP1 in P. capsici to better control it and explore the characteristics of efficient HIGS vectors. Among the 26 vectors with different lengths and structures, we found that hairpin vectors with a 70 nt loop and ~ 500 bp stem showed the highest control efficacy, with the expressing of the screened vectors, the infection and fertility of P. capsici were greatly inhibited in transgenic Nicotiana benthamiana. Based on these efficient vectors, we demonstrated that the amount of HIGS vector generated small interfering RNAs (siRNAs) was positively related to gene silencing efficiency and resistance, and that NbDCL3 and NbDCL4 were the key effectors producing siRNAs. This work discovers the principles for efficient HIGS vectors design, and elucidates the molecular mechanism of HIGS, which could benefit the control of many other plant diseases based on HIGS.
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Halder K, Chaudhuri A, Abdin MZ, Majee M, Datta A. RNA Interference for Improving Disease Resistance in Plants and Its Relevance in This Clustered Regularly Interspaced Short Palindromic Repeats-Dominated Era in Terms of dsRNA-Based Biopesticides. FRONTIERS IN PLANT SCIENCE 2022; 13:885128. [PMID: 35645997 PMCID: PMC9141053 DOI: 10.3389/fpls.2022.885128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
RNA interference (RNAi) has been exploited by scientists worldwide to make a significant contribution in the arena of sustainable agriculture and integrated pest management. These strategies are of an imperative need to guarantee food security for the teeming millions globally. The already established deleterious effects of chemical pesticides on human and livestock health have led researchers to exploit RNAi as a potential agri-biotechnology tool to solve the burning issue of agricultural wastage caused by pests and pathogens. On the other hand, CRISPR/Cas9, the latest genome-editing tool, also has a notable potential in this domain of biotic stress resistance, and a constant endeavor by various laboratories is in progress for making pathogen-resistant plants using this technique. Considerable outcry regarding the ill effects of genetically modified (GM) crops on the environment paved the way for the research of RNAi-induced double-stranded RNAs (dsRNA) and their application to biotic stresses. Here, we mainly focus on the application of RNAi technology to improve disease resistance in plants and its relevance in today's CRISPR-dominated world in terms of exogenous application of dsRNAs. We also focused on the ongoing research, public awareness, and subsequent commercialization of dsRNA-based biocontrol products.
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Affiliation(s)
- Koushik Halder
- National Institute of Plant Genome Research, New Delhi, India
- Centre for Transgenic Plant Development, Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi, India
| | - Abira Chaudhuri
- National Institute of Plant Genome Research, New Delhi, India
| | - Malik Z. Abdin
- Centre for Transgenic Plant Development, Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi, India
| | - Manoj Majee
- National Institute of Plant Genome Research, New Delhi, India
| | - Asis Datta
- National Institute of Plant Genome Research, New Delhi, India
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Noar RD, Thomas E, Daub ME. Genetic Characteristics and Metabolic Interactions between Pseudocercospora fijiensis and Banana: Progress toward Controlling Black Sigatoka. PLANTS (BASEL, SWITZERLAND) 2022; 11:948. [PMID: 35406928 PMCID: PMC9002641 DOI: 10.3390/plants11070948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 05/10/2023]
Abstract
The international importance of banana and severity of black Sigatoka disease have led to extensive investigations into the genetic characteristics and metabolic interactions between the Dothideomycete Pseudocercospora fijiensis and its banana host. P. fijiensis was shown to have a greatly expanded genome compared to other Dothideomycetes, due to the proliferation of retrotransposons. Genome analysis suggests the presence of dispensable chromosomes that may aid in fungal adaptation as well as pathogenicity. Genomic research has led to the characterization of genes and metabolic pathways involved in pathogenicity, including: secondary metabolism genes such as PKS10-2, genes for mitogen-activated protein kinases such as Fus3 and Slt2, and genes for cell wall proteins such as glucosyl phosphatidylinositol (GPI) and glycophospholipid surface (Gas) proteins. Studies conducted on resistance mechanisms in banana have documented the role of jasmonic acid and ethylene pathways. With the development of banana transformation protocols, strategies for engineering resistance include transgenes expressing antimicrobial peptides or hydrolytic enzymes as well as host-induced gene silencing (HIGS) targeting pathogenicity genes. Pseudocercospora fijiensis has been identified as having high evolutionary potential, given its large genome size, ability to reproduce both sexually and asexually, and long-distance spore dispersal. Thus, multiple control measures are needed for the sustainable control of black Sigatoka disease.
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Affiliation(s)
- Roslyn D. Noar
- NSF Center for Integrated Pest Management, North Carolina State University, Raleigh, NC 27606, USA
| | - Elizabeth Thomas
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; (E.T.); (M.E.D.)
| | - Margaret E. Daub
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; (E.T.); (M.E.D.)
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Maximiano M, Santos L, Santos C, Aragão F, Dias S, Franco O, Mehta A. Host induced gene silencing of Sclerotinia sclerotiorum effector genes for the control of white mold. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ferreira AL, de Faria JC, da Costa Moura M, de Mendonça Zaidem AL, Pizetta CSR, de Oliveira Freitas E, Coelho GRC, Silva JFAE, Barrigossi JAF, Hoffmann LV, de Souza TLPO, Aragão FJL, Pinheiro PV. Whitefly-tolerant transgenic common bean ( Phaseolus vulgaris) line. FRONTIERS IN PLANT SCIENCE 2022; 13:984804. [PMID: 36092396 PMCID: PMC9453422 DOI: 10.3389/fpls.2022.984804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 07/25/2022] [Indexed: 05/14/2023]
Abstract
Common bean (Phaseolus vulgaris L.) is a staple food in Brazil with both nutritional and socioeconomic importance. As an orphan crop, it has not received as much research attention as the commodity crops. Crop losses are strongly related to virus diseases transmitted by the whitefly Bemisia tabaci, one of the most important agricultural pests in the world. The main method of managing whitefly-transmitted viruses has been the application of insecticides to reduce vector populations. Compared to chemical vector control, a more sustainable strategy for managing insect-borne viruses is the development of resistant/tolerant cultivars. RNA interference has been applied to develop plant lines resistant to the whitefly in other species, such as tomato, lettuce and tobacco. Still, no whitefly-resistant plant has been made commercially available to date. Common bean is a recalcitrant species to in vitro regeneration; therefore, stable genetic transformation of this plant has been achieved only at low frequencies (<1%) using particle bombardment. In the present work, two transgenic common bean lines were obtained with an intron-hairpin construct to induce post-transcriptional gene silencing against the B. tabaci vATPase (Bt-vATPase) gene, with stable expression of siRNA. Northern blot analysis revealed the presence of bands of expected size for siRNA in leaf samples of the line Bt-22.5, while in the other line (11.5), the amount of siRNA produced was significantly smaller. Bioassays were conducted with both lines, but only the line Bt-22.5 was associated with significant mortality of adult insects (97% when insects were fed on detached leaves and 59% on the whole plant). The expression of the Bt-vATPase gene was 50% lower (p < 0.05) in insects that fed on the transgenic line Bt-22.5, when compared to non-transgenic controls. The transgenic line did not affect the virus transmission ability of the insects. Moreover, no effect was observed on the reproduction of non-target organisms, such as the black aphid Aphis craccivora, the leafminer Liriomyza sp. and the whitefly parasitoid Encarsia formosa. The results presented here serve as a basis for the development of whitefly-tolerant transgenic elite common bean cultivars, with potential to contribute to the management of the whitefly and virus diseases.
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Affiliation(s)
| | | | | | | | | | - Elínea de Oliveira Freitas
- Laboratory of Genetic Engineering Applied to Tropical Agriculture, Embrapa Recursos Genéticos e Biotecnologia, Brasília, Brazil
| | | | | | | | | | | | - Francisco José Lima Aragão
- Laboratory of Genetic Engineering Applied to Tropical Agriculture, Embrapa Recursos Genéticos e Biotecnologia, Brasília, Brazil
| | - Patricia Valle Pinheiro
- Laboratory of Entomology, Embrapa Arroz e Feijão, Santo Antônio de Goiás, Brazil
- Laboratory of Biotechnology, Embrapa Arroz e Feijão, Santo Antônio de Goiás, Brazil
- *Correspondence: Patricia Valle Pinheiro,
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Abstract
With the increasing understanding of fundamentals of gene silencing pathways in plants, various tools and techniques for downregulating the expression of a target gene have been developed across multiple plant species. This chapter provides an insight into the molecular mechanisms of gene silencing and highlights the advancements in various gene silencing approaches. The prominent aspects of different gene silencing methods, their advantages and disadvantages have been discussed. A succinct discussion on the newly emerged microRNA-based technologies like microRNA-induced gene silencing (MIGS) and microRNA-mediated virus-induced gene silencing (MIR-VIGS) are also presented. We have also discussed the gene-editing system like CRISPR-Cas. The prominent bottlenecks in gene silencing methods are the off-target effects and lack of universal applicability. However, the tremendous growth in understanding of this field reflects the potentials for improvements in the currently available approaches and the development of new widely applicable methods for easy, fast, and efficient functional characterization of plant genes.
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Affiliation(s)
- Prachi Pandey
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Kirankumar S Mysore
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, USA
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14
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Goulin EH, de Lima TA, dos Santos PJC, Machado MA. RNAi-induced silencing of the succinate dehydrogenase subunits gene in Colletotrichum abscissum, the causal agent of postbloom fruit drop (PFD) in citrus. Microbiol Res 2021; 260:126938. [DOI: 10.1016/j.micres.2021.126938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 09/17/2021] [Accepted: 11/28/2021] [Indexed: 11/17/2022]
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15
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Liu G, Kang G, Wang S, Huang Y, Cai Q. Extracellular Vesicles: Emerging Players in Plant Defense Against Pathogens. FRONTIERS IN PLANT SCIENCE 2021; 12:757925. [PMID: 34659325 PMCID: PMC8515046 DOI: 10.3389/fpls.2021.757925] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Communication between plants and interacting microorganisms requires functional molecule trafficking, which is essential for host defense and pathogen virulence. Extracellular vesicles (EVs) are single membrane-bound spheres that carry complex cargos, including lipids, proteins, and nucleic acids. They mediate cell-to-cell communication via the transfer of molecules between cells. Plant EVs have been isolated from many plant species and play a prominent role in immune system modulation and plant defense response. Recent studies have shown that plant EVs are emerging players in cross-kingdom regulation and contribute to plant immunity by mediating the trafficking of regulatory small RNA into pathogens, leading to the silencing of pathogen virulence-related genes. This review summarizes the current understanding of plant EV isolation technologies, the role of plant EVs in plant immunity, and the mechanism of plant EV biogenesis, as well as approaches for how these findings can be developed into innovative strategies for crop protection.
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Affiliation(s)
- Guosheng Liu
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Guangren Kang
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Shumei Wang
- Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Yifan Huang
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Qiang Cai
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
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16
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de Oliveira Filho JG, Silva GDC, Cipriano L, Gomes M, Egea MB. Control of postharvest fungal diseases in fruits using external application of RNAi. J Food Sci 2021; 86:3341-3348. [PMID: 34272735 DOI: 10.1111/1750-3841.15816] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/11/2021] [Accepted: 05/25/2021] [Indexed: 11/25/2022]
Abstract
Contamination with a variety of filamentous fungi can cause deterioration of food and agricultural products. Fungal contaminations reduce the quality and the shelf life of fresh fruits and are one of the main causes of economic loss in the global fresh fruit industry. Although chemical fungicides are effective and traditionally used to control postharvest fungal diseases, they are harmful to human health. In this context, use of RNA interference (RNAi)-based fungicides is a promising alternative strategy. Spray-induced gene silencing (SIGS) is an innovative RNAi-based approach for silencing target genes in phytopathogens. This review aims to discuss the recent findings on the use of RNAi-based fungicides to control the postharvest spoilage of fresh fruits. PRACTICAL APPLICATION: Control of postharvest fungal diseases is one of the most important strategies to make food available to consumers longer. In this sense, the external application of RNAi seems to be technologically advantageous and efficient as it helps to maintain the characteristics of plant products. In this sense, this review discussed what is possible to find in the literature regarding this new technology.
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Affiliation(s)
| | - Guilherme da Cruz Silva
- Department of Genetic and Evolution, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - Lavínia Cipriano
- Center for Biological Sciences and Health, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - Mariana Gomes
- Department of Genetic and Evolution, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - Mariana Buranelo Egea
- Goiano Federal Institute of Education, Science, and Technology, Campus Rio Verde, Rio Verde, Goiás, Brazil
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17
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Iqbal A, Khan RS, Khan MA, Gul K, Jalil F, Shah DA, Rahman H, Ahmed T. Genetic Engineering Approaches for Enhanced Insect Pest Resistance in Sugarcane. Mol Biotechnol 2021; 63:557-568. [PMID: 33893996 DOI: 10.1007/s12033-021-00328-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/19/2021] [Indexed: 10/21/2022]
Abstract
Sugarcane (Saccharum officinarum), a sugar crop commonly grown for sugar production all over the world, is susceptible to several insect pests attack in addition to bacterial, fungal and viral infections leading to substantial reductions in its yield. The complex genetic makeup and lack of resistant genes in genome of sugarcane have made the conventional breeding a difficult and challenging task for breeders. Using pesticides for control of the attacking insects can harm beneficial insects, human and other animals and the environment as well. As alternative and effective strategy for control of insect pests, genetic engineering has been applied for overexpression of cry proteins, vegetative insecticidal proteins (vip), lectins and proteinase inhibitors (PI). In addition, the latest biotechnological tools such as host-induced gene silencing (HIGS) and CRISPR/Cas9 can be employed for sustainable control of insect pests in sugarcane. In this review overexpression of the cry, vip, lectins and PI genes in transgenic sugarcane and their disease resistance potential is described.
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Affiliation(s)
- Aneela Iqbal
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan
| | - Raham Sher Khan
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan.
| | - Mubarak Ali Khan
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan
| | - Karim Gul
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan
| | - Fazal Jalil
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan
| | - Daud Ali Shah
- Department of Biotechnology, Abdul Wali Khan University, Mardan, Pakistan
| | - Hazir Rahman
- Department of Microbiology, Abdul Wali Khan University, Mardan, Pakistan
| | - Talaat Ahmed
- Department of Biological and Environmental Sciences, College of Arts and Science, Qatar University, Doha, Qatar
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18
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RNA Interference Strategies for Future Management of Plant Pathogenic Fungi: Prospects and Challenges. PLANTS 2021; 10:plants10040650. [PMID: 33805521 PMCID: PMC8067263 DOI: 10.3390/plants10040650] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022]
Abstract
Plant pathogenic fungi are the largest group of disease-causing agents on crop plants and represent a persistent and significant threat to agriculture worldwide. Conventional approaches based on the use of pesticides raise social concern for the impact on the environment and human health and alternative control methods are urgently needed. The rapid improvement and extensive implementation of RNA interference (RNAi) technology for various model and non-model organisms has provided the initial framework to adapt this post-transcriptional gene silencing technology for the management of fungal pathogens. Recent studies showed that the exogenous application of double-stranded RNA (dsRNA) molecules on plants targeting fungal growth and virulence-related genes provided disease attenuation of pathogens like Botrytis cinerea, Sclerotinia sclerotiorum and Fusarium graminearum in different hosts. Such results highlight that the exogenous RNAi holds great potential for RNAi-mediated plant pathogenic fungal disease control. Production of dsRNA can be possible by using either in-vitro or in-vivo synthesis. In this review, we describe exogenous RNAi involved in plant pathogenic fungi and discuss dsRNA production, formulation, and RNAi delivery methods. Potential challenges that are faced while developing a RNAi strategy for fungal pathogens, such as off-target and epigenetic effects, with their possible solutions are also discussed.
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McCaghey M, Shao D, Kurcezewski J, Lindstrom A, Ranjan A, Whitham SA, Conley SP, Williams B, Smith DL, Kabbage M. Host-Induced Gene Silencing of a Sclerotinia sclerotiorum oxaloacetate acetylhydrolase Using Bean Pod Mottle Virus as a Vehicle Reduces Disease on Soybean. FRONTIERS IN PLANT SCIENCE 2021; 12:677631. [PMID: 34354721 PMCID: PMC8329588 DOI: 10.3389/fpls.2021.677631] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/26/2021] [Indexed: 05/05/2023]
Abstract
A lack of complete resistance in the current germplasm complicates the management of Sclerotinia stem rot (SSR) caused by Sclerotinia sclerotiorum in soybean. In this study, we used bean pod mottle virus (BPMV) as a vehicle to down-regulate expression of a key enzyme in the production of an important virulence factor in S. sclerotiorum, oxalic acid (OA). Specifically, we targeted a gene encoding oxaloacetate acetylhydrolase (Ssoah1), because Ssoah1 deletion mutants are OA deficient and non-pathogenic on soybean. We first established that S. sclerotiorum can uptake environmental RNAs by monitoring the translocation of Cy3-labeled double-stranded and small interfering RNA (ds/siRNAs) into fungal hyphae using fluorescent confocal microscopy. This translocation led to a significant decrease in Ssoah1 transcript levels in vitro. Inoculation of soybean plants with BPMV vectors targeting Ssoah1 (pBPMV-OA) also led to decreased expression of Ssoah1. Importantly, pBPMV-OA inoculated plants showed enhanced resistance to S. sclerotiorum compared to empty-vector control plants. Our combined results provide evidence supporting the use of HIGS and exogenous applications of ds/siRNAs targeting virulence factors such as OA as viable strategies for the control of SSR in soybean and as discovery tools that can be used to identify previously unknown virulence factors.
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Affiliation(s)
- Megan McCaghey
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Dandan Shao
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Jake Kurcezewski
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Ally Lindstrom
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Ashish Ranjan
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, United States
| | - Steven A. Whitham
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Shawn P. Conley
- Department of Agronomy, University of Wisconsin-Madison, Madison, WI, United States
| | - Brett Williams
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia
| | - Damon L. Smith
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
- Damon L. Smith
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
- *Correspondence: Mehdi Kabbage
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20
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Tiwari RK, Kumar R, Sharma S, Sagar V, Aggarwal R, Naga KC, Lal MK, Chourasia KN, Kumar D, Kumar M. Potato dry rot disease: current status, pathogenomics and management. 3 Biotech 2020; 10:503. [PMID: 33163322 DOI: 10.1007/s13205-020-02496-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
Potato dry rot disease caused by Fusarium species is a major threat to global potato production. The soil and seed-borne diseases influence the crop stand by inhibiting the development of potato sprouts and cause severe rots in seed tubers, table and processing purpose potatoes in cold stores. The symptoms of the dry rot include sunken and wrinkled brown to black tissue patches on tubers having less dry matter and shriveled flesh. Fungal infection accompanied by toxin development in the rotten tubers raises more concern for consumer health. The widespread dry rot causing fungal species (Fusarium graminearum) is reported to have a hemibiotrophic lifestyle. A cascade of enzymes, toxins and small secreted proteins are involved in the pathogenesis of these hemibiotrophs. With the availability of the genome sequence of the most devastating species Fusarium sambucinum, it is important to identify the potential pathogenicity factors and small secreted proteins that will help in designing management strategies. Limited resistant cultivars and the emergence of fungicide-resistant strains have made it more threatening for potato cultivation and trade. Several novel fungicide molecules (Azoxystrobin, chlorothalonil and fludioxonil), are found very effective as tuber treatment chemicals. Besides, many beneficial bioagents and safer chemicals have shown antibiosis and mycoparasitism against this pathogen. Germplasm screening for dry rot resistance is important to assist the resistance breeding program for the development of resistant cultivars. This review aims to draw attention to the symptomatology, infection process, pathogenomics, the role of toxins and management approaches for potato dry rot disease, which is very much critical in designing better management strategies.
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Affiliation(s)
- Rahul Kumar Tiwari
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
- ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Ravinder Kumar
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
| | - Sanjeev Sharma
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
| | - Vinay Sagar
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
| | - Rashmi Aggarwal
- ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | | | - Milan Kumar Lal
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
- ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | | | - Dharmendra Kumar
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
| | - Manoj Kumar
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh 171 001 India
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21
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Abstract
Plant diseases caused by a variety of pathogens can have severe effects on crop plants and even plants in natural ecosystems. Despite many effective conventional approaches to control plant diseases, new, efficacious, environmentally sound and cost-effective approaches are needed, particularly with our increasing human population and the effects on crop production and plant health caused by climate change. RNA interference (RNAi) is a gene regulation and antiviral response mechanism in eukaryotes; transgenic and non transgenic plant-based RNAi approaches have shown great effectiveness and potential to target specific plant pathogens and help control plant diseases, especially when no alternatives are available. Here we discuss ways in which RNAi has been used against different plant pathogens, and some new potential applications for plant disease control.
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22
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Pathogenomics and Management of Fusarium Diseases in Plants. Pathogens 2020; 9:pathogens9050340. [PMID: 32369942 PMCID: PMC7281180 DOI: 10.3390/pathogens9050340] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 12/16/2022] Open
Abstract
There is an urgency to supplant the heavy reliance on chemical control of Fusarium diseases in different economically important, staple food crops due to development of resistance in the pathogen population, the high cost of production to the risk-averse grower, and the concomitant environmental impacts. Pathogenomics has enabled (i) the creation of genetic inventories which identify those putative genes, regulators, and effectors that are associated with virulence, pathogenicity, and primary and secondary metabolism; (ii) comparison of such genes among related pathogens; (iii) identification of potential genetic targets for chemical control; and (iv) better characterization of the complex dynamics of host–microbe interactions that lead to disease. This type of genomic data serves to inform host-induced gene silencing (HIGS) technology for targeted disruption of transcription of select genes for the control of Fusarium diseases. This review discusses the various repositories and browser access points for comparison of genomic data, the strategies for identification and selection of pathogenicity- and virulence-associated genes and effectors in different Fusarium species, HIGS and successful Fusarium disease control trials with a consideration of loss of RNAi, off-target effects, and future challenges in applying HIGS for management of Fusarium diseases.
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23
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Raruang Y, Omolehin O, Hu D, Wei Q, Han ZQ, Rajasekaran K, Cary JW, Wang K, Chen ZY. Host Induced Gene Silencing Targeting Aspergillus flavus aflM Reduced Aflatoxin Contamination in Transgenic Maize Under Field Conditions. Front Microbiol 2020; 11:754. [PMID: 32411110 PMCID: PMC7201132 DOI: 10.3389/fmicb.2020.00754] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/30/2020] [Indexed: 11/13/2022] Open
Abstract
Maize (Zea mays L.) is one of the major crops susceptible to Aspergillus flavus infection and subsequent contamination with aflatoxins, the most potent naturally produced carcinogenic secondary metabolites. This pathogen can pose serious health concerns and cause severe economic losses due to the Food and Drug Administration (FDA) regulations on permissible levels of aflatoxins in food and feed. Although biocontrol has yielded some successes in managing aflatoxin contamination, enhancing crop resistance is still the preferred choice of management for long-term sustainability. Hence, host induced gene silencing (HIGS) strategy was explored in this study. The A. flavus gene aflM encoding versicolorin dehydrogenase, a key enzyme involved in the aflatoxin biosynthetic pathway, was selected as a possible target for suppression through HIGS. An RNAi vector containing a portion of the aflM gene was constructed and introduced into immature B104 maize zygotic embryos through Agrobacterium transformation. PCR analysis of the genomic DNA from T0 leaf tissue confirmed the presence of the transgene in six out of the seven events. The seeds from the lines that showed reduced aflatoxin production in laboratory aflatoxin kernel screening assay (KSA) have been increased from T1 to T4 generation in the past four years. Changes in aflatoxin resistance in these transgenic kernels have been evaluated under both field and laboratory conditions. The T2 generation kernels containing the transgene from two events out of four examined had less aflatoxin (P ≤ 0.01 and P ≤ 0.08) than those without the transgene. Field-inoculated homozygous T3 and T4 transgenic kernels also revealed lower levels of aflatoxins (P ≤ 0.04) than kernels from the null (segregated non-transgenic samples) or B104 controls. A similar result was observed when the harvested T3 and T4 homozygous transgenic kernels were evaluated under KSA conditions without inoculation (P ≤ 0.003–0.05). These two events were crossed with LH195, LH197, LH210, and PHW79 elite breeding lines and the resulting crosses supported less aflatoxin (P ≤ 0.02) than the crosses made with non-transgenic lines. In addition, significantly higher levels of aflM gene-specific small RNAs were detected in the transgenic leaf and kernel tissues, indicating that the enhanced aflatoxin resistance in the homozygous transgenic kernels is likely due to suppression of aflM expression through HIGS.
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Affiliation(s)
- Yenjit Raruang
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Olanike Omolehin
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Dongfang Hu
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Qijian Wei
- Food and Feed Safety Research Unit, United States Department of Agriculture - Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Zhu-Qiang Han
- Cash Crops Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, United States Department of Agriculture - Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Jeffrey W Cary
- Food and Feed Safety Research Unit, United States Department of Agriculture - Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Kan Wang
- Department of Agronomy, Iowa State University, Ames, IA, United States
| | - Zhi-Yuan Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
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Omics applications: towards a sustainable protection of tomato. Appl Microbiol Biotechnol 2020; 104:4185-4195. [PMID: 32185431 DOI: 10.1007/s00253-020-10500-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 12/20/2022]
Abstract
Transcriptome data and gene expression analysis have a huge potential in the study of multiple relationships involving plants, pathogens, and pests, including the interactions with beneficial microorganisms such as endophytes or other functional groups. Next-generation sequencing (NGS) and other recent long-read-based sequencing approaches (i.e., nanopore and others) provide unprecedented tools allowing the fast identification of plant information processing systems, in situ and in real time, fundamental for crop management and pest regulation. Other -omics approaches such as metagenomics and metatranscriptomics allow high-resolution insights on the rhizosphere ecology. They may highlight key factors affecting belowground biodiversity or processes, modulating the expression of stress-responsive pathways. The application of miRNAs and other small RNAs is a relatively new field of application, with enormous potential for the selective activation of defense pathways. However, limitations concerning the stability of the RNA molecules and their effective delivery must be overcome.
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25
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Haque MA, Wang Y, Shen Z, Li X, Saleemi MK, He C. Mycotoxin contamination and control strategy in human, domestic animal and poultry: A review. Microb Pathog 2020; 142:104095. [PMID: 32097745 DOI: 10.1016/j.micpath.2020.104095] [Citation(s) in RCA: 174] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/17/2020] [Accepted: 02/21/2020] [Indexed: 12/12/2022]
Abstract
Mycotoxins are secondary metabolites produced mainly by fungi belonging to the genera Aspergillus, Fusarium, Penicillium, Claviceps, and Alternaria that contaminate basic food products throughout the world, where developing countries are becoming predominantly affected. Currently, more than 500 mycotoxins are reported in which the most important concern to public health and agriculture include AFB1, OTA, TCTs (especially DON, T-2, HT-2), FB1, ZEN, PAT, CT, and EAs. The presence of mycotoxin in significant quantities poses health risks varying from allergic reactions to death on both humans and animals. This review brings attention to the present status of mycotoxin contamination of food products and recommended control strategies for mycotoxin mitigation. Humans are exposed to mycotoxins directly through the consumption of contaminated foods while, indirectly through carryover of toxins and their metabolites into animal tissues, milk, meat and eggs after ingestion of contaminated feeds. Pre-harvest (field) control of mycotoxin production and post-harvest (storage) mitigation of contamination represent the most effective approach to limit mycotoxins in food and feed. Compared with chemical and physical approaches, biological detoxification methods regarding biotransformation of mycotoxins into less toxic metabolites, are generally more unique, productive and eco-friendly. Along with the biological detoxification method, genetic improvement and application of nanotechnology show tremendous potential in reducing mycotoxin production thereby improving food safety and food quality for extended shelf life. This review will primarily describe the latest developments in the formation and detoxification of the most important mycotoxins by biological degradation and other alternative approaches, thereby reducing the potential adverse effects of mycotoxins.
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Affiliation(s)
- Md Atiqul Haque
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China; Department of Microbiology, Faculty of Veterinary & Animal Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur, 5200, Bangladesh
| | - Yihui Wang
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Zhiqiang Shen
- Binzhou Animal Science and Veterinary Medicine Academy of Shandong Province, Binzhou, 256600, China
| | - Xiaohui Li
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Muhammad Kashif Saleemi
- Department of Pathology, Faculty of Veterinary Science, University of Agriculture, Faisalabad, 38040, Pakistan
| | - Cheng He
- Key Lab of Animal Epidemiology and Zoonoses of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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26
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Su X, Lu G, Li X, Rehman L, Liu W, Sun G, Guo H, Wang G, Cheng H. Host-Induced Gene Silencing of an Adenylate Kinase Gene Involved in Fungal Energy Metabolism Improves Plant Resistance to Verticillium dahliae. Biomolecules 2020; 10:E127. [PMID: 31940882 PMCID: PMC7023357 DOI: 10.3390/biom10010127] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 12/11/2022] Open
Abstract
Verticillium wilt, caused by the ascomycete fungus Verticillium dahliae (Vd), is a devastating disease of numerous plant species. However, the pathogenicity/virulence-related genes in this fungus, which may be potential targets for improving plant resistance, remain poorly elucidated. For the study of these genes in Vd, we used a well-established host-induced gene silencing (HIGS) approach and identified 16 candidate genes, including a putative adenylate kinase gene (VdAK). Transiently VdAK-silenced plants developed milder wilt symptoms than control plants did. VdAK-knockout mutants were more sensitive to abiotic stresses and had reduced germination and virulence on host plants. Transgenic Nicotiana benthamiana and Arabidopsis thaliana plants that overexpressed VdAK dsRNAs had improved Vd resistance than the wild-type. RT-qPCR results showed that VdAK was also crucial for energy metabolism. Importantly, in an analysis of total small RNAs from Vd strains isolated from the transgenic plants, a small interfering RNA (siRNA) targeting VdAK was identified in transgenic N. benthamiana. Our results demonstrate that HIGS is a promising strategy for efficiently screening pathogenicity/virulence-related genes of Vd and that VdAK is a potential target to control this fungus.
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Affiliation(s)
- Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
| | - Guoqing Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
| | - Xiaokang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
| | - Latifur Rehman
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
- Department of Biotechnology, University of Swabi, Khyber Pakhtunkhwa 23561, Pakistan
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
| | - Guoqing Sun
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
| | - Huiming Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
| | - Guoliang Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
- Department of Plant Pathology, Ohio State University, Columbus, OH 43210, USA
| | - Hongmei Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.S.); (G.L.); (X.L.); (L.R.); (G.S.); (H.G.)
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Prasad P, Savadi S, Bhardwaj SC, Gangwar OP, Kumar S. Rust pathogen effectors: perspectives in resistance breeding. PLANTA 2019; 250:1-22. [PMID: 30980247 DOI: 10.1007/s00425-019-03167-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Identification and functional characterization of plant pathogen effectors promise to ameliorate future research and develop effective and sustainable strategies for controlling or containing crop diseases. Wheat is the second most important food crop of the world after rice. Rust pathogens, one of the major biotic stresses in wheat production, are capable of threatening the world food security. Understanding the molecular basis of plant-pathogen interactions is essential for devising novel strategies for resistance breeding and disease management. Now, it has been established that effectors, the proteins secreted by pathogens, play a key role in plant-pathogen interactions. Therefore, effector biology has emerged as one of the most important research fields in plant biology. Recent advances in genomics and bioinformatics have allowed identification of a large repertoire of candidate effectors, while the evolving high-throughput tools have continued to assist in their functional characterization. The repertoires of effectors have become an important resource for better understanding of effector biology of pathosystems and resistance breeding of crop plants. In recent years, a significant progress has been made in the field of rust effector biology. This review describes the recent advances in effector biology of obligate fungal pathogens, identification and functional analysis of wheat rust pathogens effectors and the potential applications of effectors in molecular plant biology and rust resistance breeding in wheat.
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Affiliation(s)
- Pramod Prasad
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Siddanna Savadi
- ICAR-Directorate of Cashew Research, Puttur, Karnataka, 574202, India
| | - S C Bhardwaj
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India.
| | - O P Gangwar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Subodh Kumar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
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Ramírez-Valdespino CA, Casas-Flores S, Olmedo-Monfil V. Trichoderma as a Model to Study Effector-Like Molecules. Front Microbiol 2019; 10:1030. [PMID: 31156578 PMCID: PMC6529561 DOI: 10.3389/fmicb.2019.01030] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/24/2019] [Indexed: 11/24/2022] Open
Abstract
Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant–microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them.
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Affiliation(s)
- Claudia A Ramírez-Valdespino
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Guanajuato, Mexico.,Laboratorio de Biohidrometalurgia, Departamento de Medio Ambiente y Energía, Centro de Investigación en Materiales Avanzados, Chihuahua, Mexico
| | - Sergio Casas-Flores
- Laboratorio de Genómica Funcional y Comparativa, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, Mexico
| | - Vianey Olmedo-Monfil
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Guanajuato, Mexico
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29
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Ramírez-Valdespino CA, Casas-Flores S, Olmedo-Monfil V. Trichoderma as a Model to Study Effector-Like Molecules. Front Microbiol 2019. [PMID: 31156578 DOI: 10.3389/pmic.2019.01030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023] Open
Abstract
Plants are capable of perceiving microorganisms by coordinating processes to establish different forms of plant-microbe relationships. Plant colonization is governed in fungal and bacterial systems by secreted effector molecules, suppressing plant defense responses and modulating plant physiology to promote either virulence or compatibility. Proteins, secondary metabolites, and small RNAs have been described as effector molecules that use different mechanisms to establish the interaction. Effector molecules have been studied in more detail due to their involvement in harmful interactions, leading to a negative impact on agriculture. Recently, research groups have started to study the effectors in symbiotic interactions. Interestingly, most symbiotic effectors are members of the same families present in phytopathogens. Nevertheless, the quantity and ratio of secreted effectors depends on the microorganism and the host, suggesting a complex mechanism of recognition between the plant and their associated microorganisms. Fungi belonging to Trichoderma genus interact with plants by inducing their defense system and promoting plant growth. Research suggests that some of these effects are associated with effector molecules that Trichoderma delivers during the association with the plant. In this review, we will focus on the main findings concerning the effector molecules reported in Trichoderma spp. and their role during the interaction with plants, mainly in the molecular dialogue that takes place between them.
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Affiliation(s)
- Claudia A Ramírez-Valdespino
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Guanajuato, Mexico
- Laboratorio de Biohidrometalurgia, Departamento de Medio Ambiente y Energía, Centro de Investigación en Materiales Avanzados, Chihuahua, Mexico
| | - Sergio Casas-Flores
- Laboratorio de Genómica Funcional y Comparativa, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, Mexico
| | - Vianey Olmedo-Monfil
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Guanajuato, Mexico
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Song X, Gu K, Duan X, Xiao X, Hou Y, Duan Y, Wang J, Yu N, Zhou M. Secondary amplification of siRNA machinery limits the application of spray-induced gene silencing. MOLECULAR PLANT PATHOLOGY 2018; 19:2543-2560. [PMID: 30027625 PMCID: PMC6638038 DOI: 10.1111/mpp.12728] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Spray-induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA (siRNA) amplification limits the application of SIGS. A myosin5 gene (Myo5) was chosen as the target of SIGS in an agronomically important pathogen-Fusarium asiaticum. Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5, resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5-8 (one of the Myo5 segments) induced sequence-specific RNA interference (RNAi) activity in F. asiaticum, F. graminearum, F. tricinctum and F. oxysporum, but not in other fungi, in vitro. Remarkably, the silencing of Myo5 lasted for only 9 h unless the double-stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.
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Affiliation(s)
- Xiu‐Shi Song
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Kai‐Xin Gu
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Xiao‐Xin Duan
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Xue‐Mei Xiao
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Yi‐Ping Hou
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Ya‐Bing Duan
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Jian‐Xin Wang
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Na Yu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Ming‐Guo Zhou
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
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31
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Baldwin T, Islamovic E, Klos K, Schwartz P, Gillespie J, Hunter S, Bregitzer P. Silencing efficiency of dsRNA fragments targeting Fusarium graminearum TRI6 and patterns of small interfering RNA associated with reduced virulence and mycotoxin production. PLoS One 2018; 13:e0202798. [PMID: 30161200 PMCID: PMC6116998 DOI: 10.1371/journal.pone.0202798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 08/09/2018] [Indexed: 01/02/2023] Open
Abstract
Deoxynivalenol (DON) contamination of cereal grains caused by Fusarium head blight may be addressed by future RNA interference (RNAi)-based gene silencing approaches. However, utilizing these approaches will require a greater understanding of the principles that govern RNAi effectiveness in the pathogen Fusarium graminearum. RNAi in higher eukaryotes, including fungi, involves processing double stranded RNA (dsRNA) into small interfering RNA (siRNA) that silence gene expression based on base pair complementarity. This study examined virulence, DON production, and the small RNA (sRNA) populations in response to RNAi-based silencing of TRI6, a transcription factor that positively regulates DON synthesis via control of TRI5 expression. Silencing was accomplished via the expression of transgenes encoding inverted repeats targeting various regions of TRI6 (RNAi vectors). Transgene expression was associated with novel, TRI6-specific siRNAs. For RNAi vectors targeting the majority of TRI6 sequence (~600 bp), a discontinuous, repeatable pattern was observed in which most siRNAs mapped to specific regions of TRI6. Targeting shorter regions (250-350 bp) did not alter the siRNA populations corresponding to that region of TRI6. No phased processing was observed. The 5' base of ~83% of siRNAs was uracil, consistent with DICER processing and ARGONAUTE binding preferences for siRNA. Mutant lines showed TRI6 siRNA-associated reductions of TRI5 expression on toxin inducing media and DON in infected wheat and barley spikes. Shorter RNAi vectors resulted in variable levels of silencing that were less than for the ~600 bp RNAi vector, with a 343 bp RNAi vector targeting the 5' end of TRI6 having the best silencing efficiency. This work identifies efficient shorter region for silencing of TRI6 and describes the patterns of siRNA corresponding to those regions.
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Affiliation(s)
- Thomas Baldwin
- National Small Grains Germplasm Research Facility, USDA-ARS, Aberdeen, Idaho, United States of America
| | - Emir Islamovic
- BASF, Research Triangle Park, NC, United States of America
| | - Kathy Klos
- National Small Grains Germplasm Research Facility, USDA-ARS, Aberdeen, Idaho, United States of America
| | - Paul Schwartz
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States of America
| | - James Gillespie
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States of America
| | - Samuel Hunter
- iBEST, University of Idaho, Moscow, ID, United States of America
| | - Phil Bregitzer
- National Small Grains Germplasm Research Facility, USDA-ARS, Aberdeen, Idaho, United States of America
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Gosal SS, Wani SH. RNAi for Resistance Against Biotic Stresses in Crop Plants. BIOTECHNOLOGIES OF CROP IMPROVEMENT, VOLUME 2 2018. [PMCID: PMC7123769 DOI: 10.1007/978-3-319-90650-8_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RNA interference (RNAi)-based gene silencing has become one of the most successful strategies in not only identifying gene function but also in improving agronomical traits of crops by silencing genes of different pathogens/pests and also plant genes for improvement of desired trait. The conserved nature of RNAi pathway across different organisms increases its applicability in various basic and applied fields. Here we attempt to summarize the knowledge generated on the fundamental mechanisms of RNAi over the years, with emphasis on insects and plant-parasitic nematodes (PPNs). This chapter also reviews the rich history of RNAi research, gene regulation by small RNAs across different organisms, and application potential of RNAi for generating transgenic plants resistant to major pests. But, there are some limitations too which restrict wider applications of this technology to its full potential. Further refinement of this technology in terms of resolving these shortcomings constitutes one of the thrust areas in present RNAi research. Nevertheless, its application especially in breeding agricultural crops resistant against biotic stresses will certainly offer the possible solutions for some of the breeding objectives which are otherwise unattainable.
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Affiliation(s)
- Satbir Singh Gosal
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab India
| | - Shabir Hussain Wani
- Mountain Research Centre for Field Crops, Khudwani, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, Jammu and Kashmir India
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33
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Panwar V, Jordan M, McCallum B, Bakkeren G. Host-induced silencing of essential genes in Puccinia triticina through transgenic expression of RNAi sequences reduces severity of leaf rust infection in wheat. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:1013-1023. [PMID: 28941315 PMCID: PMC5902777 DOI: 10.1111/pbi.12845] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 08/18/2017] [Accepted: 09/20/2017] [Indexed: 05/05/2023]
Abstract
Leaf rust, caused by the pathogenic fungus Puccinia triticina (Pt), is one of the most serious biotic threats to sustainable wheat production worldwide. This obligate biotrophic pathogen is prevalent worldwide and is known for rapid adaptive evolution to overcome resistant wheat varieties. Novel disease control approaches are therefore required to minimize the yield losses caused by Pt. Having shown previously the potential of host-delivered RNA interference (HD-RNAi) in functional screening of Pt genes involved in pathogenesis, we here evaluated the use of this technology in transgenic wheat plants as a method to achieve protection against wheat leaf rust (WLR) infection. Stable expression of hairpin RNAi constructs with sequence homology to Pt MAP-kinase (PtMAPK1) or a cyclophilin (PtCYC1) encoding gene in susceptible wheat plants showed efficient silencing of the corresponding genes in the interacting fungus resulting in disease resistance throughout the T2 generation. Inhibition of Pt proliferation in transgenic lines by in planta-induced RNAi was associated with significant reduction in target fungal transcript abundance and reduced fungal biomass accumulation in highly resistant plants. Disease protection was correlated with the presence of siRNA molecules specific to targeted fungal genes in the transgenic lines harbouring the complementary HD-RNAi construct. This work demonstrates that generating transgenic wheat plants expressing RNAi-inducing transgenes to silence essential genes in rust fungi can provide effective disease resistance, thus opening an alternative way for developing rust-resistant crops.
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Affiliation(s)
- Vinay Panwar
- Agriculture and Agri‐Food CanadaMorden Research and Development CentreMordenMBCanada
- Agriculture and Agri‐Food CanadaSummerland Research and Development CentreSummerlandBCCanada
| | - Mark Jordan
- Agriculture and Agri‐Food CanadaMorden Research and Development CentreMordenMBCanada
| | - Brent McCallum
- Agriculture and Agri‐Food CanadaMorden Research and Development CentreMordenMBCanada
| | - Guus Bakkeren
- Agriculture and Agri‐Food CanadaSummerland Research and Development CentreSummerlandBCCanada
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34
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Faustinelli PC, Power IL, Arias RS. Detection of exogenous double-stranded RNA movement in in vitro peanut plants. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:444-449. [PMID: 29405546 DOI: 10.1111/plb.12703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/30/2018] [Indexed: 06/07/2023]
Abstract
New technologies are needed to eliminate mycotoxins and/or fungal pathogens from agricultural products. RNA interference (RNAi) has shown potential to control fungi associated with crops. In RNAi, double-stranded RNA (dsRNA) targets homologous mRNA for cleavage, and can reach the mRNA of pathogens in contact with the plant. The key element in this process is the movement of RNA signals cell-to-cell and over long distances within the plant, and between host plants and parasites. In this study, we selected a regulatory gene in the aflatoxin biosynthesis pathway, aflS/aflR, necessary for the production of aflatoxins in Aspergillus spp. We designed a Dicer-substrate RNA (DsiRNA) to study the movement and stability of the duplex over time in in vitro peanut plants using stem-loop primers and RT-PCR for DsiRNA detection. The preliminary results demonstrated that DsiRNA was absorbed and moved away from the point of application, spread systemically and was transported rapidly, most likely through the phloem of the shoot, to the sink tissues, such as new auxiliary shoots, flowers and newly formed pegs. The DsiRNA remained detectable for at least 30 days after treatment. This is the first time that movement of exogenous DsiRNA in in vitro peanut plants has been described. Since DsiRNA was detectable in the pegs 15 days after treatment, aflatoxin reduction may be possible if the duplexes containing part of the aflatoxin biosynthesis pathogen gene induce silencing in the peanut seeds colonised by Aspergillus spp. The application of small RNAs could be a non-transformative option for mycotoxin contamination control.
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Affiliation(s)
- P C Faustinelli
- USDA-ARS National Peanut Research Laboratory, Dawson, GA, USA
| | - I L Power
- USDA-ARS National Peanut Research Laboratory, Dawson, GA, USA
| | - R S Arias
- USDA-ARS National Peanut Research Laboratory, Dawson, GA, USA
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35
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Host-Induced Silencing of Pathogenicity Genes Enhances Resistance to Fusarium oxysporum Wilt in Tomato. Mol Biotechnol 2018; 59:343-352. [PMID: 28674943 DOI: 10.1007/s12033-017-0022-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study presents a novel approach of controlling vascular wilt in tomato by RNAi expression directed to pathogenicity genes of Fusarium oxysporum f. sp. lycopersici. Vascular wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici leads to qualitative and quantitative loss of the crop. Limitation in the existing control measures necessitates the development of alternative strategies to increase resistance in the plants against pathogens. Recent findings paved way to RNAi, as a promising method for silencing of pathogenicity genes in fungus and provided effective resistance against fungal pathogens. Here, two important pathogenicity genes FOW2, a Zn(II)2Cys6 family putative transcription regulator, and chsV, a putative myosin motor and a chitin synthase domain, were used for host-induced gene silencing through hairpinRNA cassettes of these genes against Fusarium oxysporum f. sp. lycopersici. HairpinRNAs were assembled in appropriate binary vectors and transformed into tomato plant targeting FOW2 and chsV genes, for two highly pathogenic strains of Fusarium oxysporum viz. TOFOL-IHBT and TOFOL-IVRI. Transgenic tomatoes were analyzed for possible attainment of resistance in transgenic lines against fungal infection. Eight transgenic lines expressing hairpinRNA cassettes showed trivial disease symptoms after 6-8 weeks of infection. Hence, the host-induced posttranscriptional gene silencing of pathogenicity genes in transgenic tomato plants has enhanced their resistance to vascular wilt disease caused by Fusarium oxysporum.
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36
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Machado AK, Brown NA, Urban M, Kanyuka K, Hammond‐Kosack KE. RNAi as an emerging approach to control Fusarium head blight disease and mycotoxin contamination in cereals. PEST MANAGEMENT SCIENCE 2018; 74:790-799. [PMID: 28967180 PMCID: PMC5873435 DOI: 10.1002/ps.4748] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/11/2017] [Accepted: 09/22/2017] [Indexed: 05/21/2023]
Abstract
Fusarium graminearum is a major fungal pathogen of cereals worldwide, causing seedling, stem base and floral diseases, including Fusarium head blight (FHB). In addition to yield and quality losses, FHB contaminates cereal grain with mycotoxins, including deoxynivalenol, which are harmful to human, animal and ecosystem health. Currently, FHB control is only partially effective due to several intractable problems. RNA interference (RNAi) is a natural mechanism that regulates gene expression. RNAi has been exploited in the development of new genomic tools that allow the targeted silencing of genes of interest in many eukaryotes. Host-induced gene silencing (HIGS) is a transgenic technology used to silence fungal genes in planta during attempted infection and thereby reduces disease levels. HIGS relies on the host plant's ability to produce mobile small interfering RNA molecules, generated from long double-stranded RNA, which are complementary to targeted fungal genes. These molecules are transferred from the plant to invading fungi via an uncharacterised mechanism, to cause gene silencing. Here, we describe recent advances in RNAi-mediated control of plant pathogenic fungi, highlighting the key advantages and disadvantages. We then discuss the developments and implications of combining HIGS with other methods of disease control. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Ana Karla Machado
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Neil A Brown
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- Department of Biology & BiochemistryUniversity of Bath, Claverton DownBathUK
| | - Martin Urban
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Kostya Kanyuka
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
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37
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Jin Y, Zhao P, Fang YY, Gao F, Guo HS, Zhao JH. Genome-wide profiling of sRNAs in the Verticillium dahliae-infected Arabidopsis roots. Mycology 2018; 9:155-165. [PMID: 30181922 PMCID: PMC6115885 DOI: 10.1080/21501203.2018.1426062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/05/2018] [Indexed: 11/23/2022] Open
Abstract
Small RNAs (sRNAs, including small interfering RNAs [siRNAs] and micro RNAs [miRNAs]) are key mediators of RNA silencing (or RNA interference), which play important roles in plant development and response to biotic and abiotic stimulation. Verticillium wilt is a plant vascular disease caused by the soil-borne fungal pathogens, such as Verticillium dahliae. We previously reported that V. dahliae infection increased two plant endogenous miRNAs that were exported to fungal cell to silence virulence genes. To investigate plant sRNAs in genome-wide response to V. dahliae infection, in this study, we constructed two sRNA libraries from Arabidopsis roots with and without V. dahliae infection, respectively. In total, 31 conserved miRNAs were found to be differentially expressed during the early stage of infection with V. dahliae using sRNA sequencing. Among these, the expression levels of miR160, miR164, miR166, miR167, miR390 and miR156h were confirmed by northern blot. Reverse transcription quantitative real time polymerase chain reaction results showed that the induction of miRNAs (miR160, miR164, miR166 and miR167) upon V. dahliae infection downregulated the expression of their targeted genes (ARF10, NAC1, PHV and ARF6), respectively. In addition, we identified specific phased siRNAs generated from distinct regions of two libraries. Profiling of these miRNAs and sRNAs lay the foundation for further understanding and utilising the host-induced gene silencing strategy to control plant vascular pathogens.
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Affiliation(s)
- Yun Jin
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina
| | - Pan Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina
| | - Yuan-Yuan Fang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina
| | - Feng Gao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina.,College of Agriculture, Shihezi University and Key Laboratory at Universities of Xinjiang Uygur Autonomous Region for Oasis Agricultural Pest Management and Plant Protection Resource Utilization, Shihezi, China
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina.,College of Life Science, University of the Chinese Academy of Sciences, Beijing, China
| | - Jian-Hua Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, BeijingChina
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38
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Muñoz-Adalia EJ, Diez JJ, Fernández MM, Hantula J, Vainio EJ. Characterization of small RNAs originating from mitoviruses infecting the conifer pathogen Fusarium circinatum. Arch Virol 2018; 163:1009-1018. [PMID: 29353424 DOI: 10.1007/s00705-018-3712-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/27/2017] [Indexed: 12/13/2022]
Abstract
Deep sequencing of small RNAs has proved effective in the diagnosis of mycovirus infections. In this study, the presence of mycoviruses in ten isolates of the phytopathogenic fungus Fusarium circinatum was investigated by high-throughput sequencing (HTS) of small RNAs. The contigs resulting from de novo assembly of the reads were aligned to viral genome sequences. The presence of each mycovirus detected in the isolates was confirmed by RT-PCR analysis with four previously described primer pairs and seven new pairs designed on the basis of sequencing data. The findings demonstrate the potential use of HTS for reconstructing previously identified mitoviruses infecting F. circinatum.
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Affiliation(s)
- E J Muñoz-Adalia
- Sustainable Forest Management Research Institute, University of Valladolid-INIA, Avenida de Madrid 44, 34071, Palencia, Spain. .,Department of Vegetal Production and Forest Resources, University of Valladolid, Avenida de Madrid 44, 34071, Palencia, Spain.
| | - J J Diez
- Sustainable Forest Management Research Institute, University of Valladolid-INIA, Avenida de Madrid 44, 34071, Palencia, Spain.,Department of Vegetal Production and Forest Resources, University of Valladolid, Avenida de Madrid 44, 34071, Palencia, Spain
| | - M M Fernández
- Sustainable Forest Management Research Institute, University of Valladolid-INIA, Avenida de Madrid 44, 34071, Palencia, Spain.,Department of Agroforestry Sciences, University of Valladolid, Avenida de Madrid 44, 34071, Palencia, Spain
| | - J Hantula
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790, Helsinki, Finland
| | - E J Vainio
- Forest Health and Biodiversity, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790, Helsinki, Finland
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Song Y, Thomma BPHJ. Host-induced gene silencing compromises Verticillium wilt in tomato and Arabidopsis. MOLECULAR PLANT PATHOLOGY 2018; 19:77-89. [PMID: 27749994 PMCID: PMC6638114 DOI: 10.1111/mpp.12500] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 10/11/2016] [Accepted: 10/12/2016] [Indexed: 05/03/2023]
Abstract
Verticillium wilt, caused by soil-borne fungi of the genus Verticillium, is an economically important disease that affects a wide range of host plants. Unfortunately, host resistance against Verticillium wilts is not available for many plant species, and the disease is notoriously difficult to combat. Host-induced gene silencing (HIGS) is an RNA interference (RNAi)-based process in which small RNAs are produced by the host plant to target parasite transcripts. HIGS has emerged as a promising strategy for the improvement of plant resistance against pathogens by silencing genes that are essential for these pathogens. Here, we assessed whether HIGS can be utilized to suppress Verticillium wilt disease by silencing three previously identified virulence genes of V. dahliae (encoding Ave1, Sge1 and NLP1) through the host plants tomato and Arabidopsis. In transient assays, tomato plants were agroinfiltrated with Tobacco rattle virus (TRV) constructs to target V. dahliae transcripts. Subsequent V. dahliae inoculation revealed the suppression of Verticillium wilt disease on treatment with only one of the three TRV constructs. Next, expression of RNAi constructs targeting transcripts of the same three V. dahliae virulence genes was pursued in stable transgenic Arabidopsis thaliana plants. In this host, V. dahliae inoculation revealed reduced Verticillium wilt disease in two of the three targets. Thus, our study suggests that, depending on the target gene chosen, HIGS against V. dahliae is operational in tomato and A. thaliana plants and may be exploited to engineer resistance in Verticillium wilt-susceptible crops.
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Affiliation(s)
- Yin Song
- Laboratory of PhytopathologyWageningen University, Droevendaalsesteeg 1Wageningen6708 PBthe Netherlands
| | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen University, Droevendaalsesteeg 1Wageningen6708 PBthe Netherlands
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Yin C, Hulbert SH. Host-Induced Gene Silencing (HIGS) for Elucidating Puccinia Gene Function in Wheat. Methods Mol Biol 2018; 1848:139-150. [PMID: 30182235 DOI: 10.1007/978-1-4939-8724-5_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Biotrophic fungi (Puccinia spp.) cause devastating diseases of wheat and other cereal species globally. The function of large repertories of genes from Puccinia spp. still needs to be discovered to understand the infection process of these obligate parasites, eventually to protect plants from rust diseases. Functional analysis of targeted genes is challenging due to the inherent difficulties with culturing the fungus and transforming the host. RNA interference (RNAi) is a conserved gene regulation process in eukaryotes and known to be a powerful genetic tool in plant biotechnology. More recently, host-induced gene silencing (HIGS) has been developed to assess pathogen gene function in plants. HIGS is an RNAi-based process where double stranded RNA (dsRNA) homologous to a pathogen gene can be expressed in a plant to induce targeted silencing of the pathogen gene. Here we described a detailed HIGS protocol for functional analysis of rust genes from Puccinia species in cereals. As an example we describe an experiment silencing the tryptophan 2-monooxygenase gene (Pgt-IaaM) from Puccinia graminis f. sp. tritici (Pgt) that is involved in virulence to wheat.
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Affiliation(s)
- Chuntao Yin
- Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Scot H Hulbert
- Department of Plant Pathology, Washington State University, Pullman, WA, USA.
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Abstract
The comprehension of fungal biology is important for several reasons. Besides being used in biotechnological processes and in the food industry, fungi are also important animal and vegetal pathogens. Fungal diseases in humans have a great importance worldwide, and understanding fungal biology is crucial for treatment and prevention of these diseases, especially because of emerging antifungal resistance that poses great epidemiological risks. Communication through extracellular vesicles is a ubiquitous mechanism of molecule transfer between cells and is used to transport proteins, nucleic acids, lipids, and other biologically active molecules. Several pathogens can produce and transfer extracellular vesicles, and the importance of this pathway in fungal communication with hosts and between fungal cells has been described for several species in the last years, as shown for Saccharomyces cereviseae, Cryptococcus neoformans, Candida albicans, Paracoccidioides braziliensis, Sporothrix schenckii, Candida parapsilosis, Malassezia sympodialis, Histoplasma capsulatum, among others. In this chapter, we review the role of extracellular vesicles in fungal communication, interaction with hosts and with the environment, and also highlighting important molecules found in fungal EVs.
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Wadhwa G, Shanmughavel P, Singh AK, Bellare JR. Computational Tools: RNA Interference in Fungal Therapeutics. CURRENT TRENDS IN BIOINFORMATICS: AN INSIGHT 2018. [PMCID: PMC7122507 DOI: 10.1007/978-981-10-7483-7_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
There is steady rise in the number of immunocompromised population due to increased use of potent immunosuppression therapies. This is associated with increased risk of acquiring fungal opportunistic infections in immunocompromised patients which account for high morbidity and mortality rates, if left untreated. The conventional antifungal drugs to treat fungal diseases (mycoses) are increasingly becoming inadequate due to observed varied susceptibility of fungi and their recurrent resistance. RNA interference (RNAi), sequence-specific gene silencing, is emerging as a promising new therapeutic approach. This chapter discusses various aspects of RNAi, viz., the fundamental RNAi machinery present in fungi, in silico siRNA features, designing guidelines and tools, siRNA delivery, and validation of gene knockdown for therapeutics against mycoses. Target gene identification is a crucial step in designing of gene-specific siRNA in addition to efficient delivery strategies to bring about effective inhibition of fungi. Subsequently, designed siRNA can be delivered effectively in vitro either by soaking fungi with siRNA or by transforming inverted repeat transgene containing plasmid into fungi, which ultimately generates siRNA(s). Finally, fungal inhibition can be verified at the RNA and protein levels by blotting techniques, fluorescence imaging, and biochemical assays. Despite challenges, several such in vitro studies have spawned optimism around RNAi as a revolutionary new class of therapeutics against mycoses. But, pharmacokinetic parameters need to be evaluated from in vivo studies and clinical trials to recognize RNAi as a novel treatment approach for mycoses.
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Affiliation(s)
- Gulshan Wadhwa
- Department of Biotechnology Apex Bioinformatics Centre, Ministry of Science & Technology, New Delhi, India
| | - P. Shanmughavel
- Department of Bioinformatics, Bharathiar University, Coimbatore, Tamil Nadu India
| | - Atul Kumar Singh
- Central Research Facility, Indian Institute of Technology Delhi, New Delhi, India
| | - Jayesh R. Bellare
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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Reducing production of fumonisin mycotoxins in Fusarium verticillioides by RNA interference. Mycotoxin Res 2017; 34:29-37. [DOI: 10.1007/s12550-017-0296-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/19/2017] [Accepted: 10/24/2017] [Indexed: 12/28/2022]
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Ibrahim AB, Monteiro TR, Cabral GB, Aragão FJL. RNAi-mediated resistance to whitefly (Bemisia tabaci) in genetically engineered lettuce (Lactuca sativa). Transgenic Res 2017; 26:613-624. [PMID: 28712067 DOI: 10.1007/s11248-017-0035-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 07/10/2017] [Indexed: 01/09/2023]
Abstract
RNA interference (RNAi)-based transgenic technologies have evolved as potent biochemical tools for silencing specific genes of plant pathogens and pests. The approach has been demonstrated to be useful in silencing genes in insect species. Here, we report on the successful construction of RNAi-based plasmid containing an interfering cassette designed to generate dsRNAs that target a novel v-ATPase transcript in whitefly (Bemisia tabaci), an important agricultural pest in tropical and sub-tropical regions. The presence of the transgene was confirmed in T0 and T1 generations of transgenic lettuce lines, segregating in a Mendelian fashion. Seven lines were infested with whiteflies and monitored over a period of 32 days. Analysis of mortality showed that within five days of feeding, insects on transgenic plants showed a mortality rate of 83.8-98.1%. In addition, a reduced number of eggs (95 fold less) was observed in flies feeding on transgenic lettuce plants than insects on control lines. Quantitative reverse transcription PCR showed decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. This technology is a foundation for the production of whitefly-resistant commercial crops, improving agricultural sustainability and food security, reducing the use of more environmentally aggressive methods of pest control.
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Affiliation(s)
- Abdulrazak B Ibrahim
- Embrapa Recursos Genéticos e Biotecnologia, PqEB W5 Norte, Brasília, DF, 70770-900, Brazil
- Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário, Brasília, DF, 70910-900, Brazil
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria
| | - Tatiane R Monteiro
- Embrapa Recursos Genéticos e Biotecnologia, PqEB W5 Norte, Brasília, DF, 70770-900, Brazil
- Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário, Brasília, DF, 70910-900, Brazil
| | - Glaucia B Cabral
- Embrapa Recursos Genéticos e Biotecnologia, PqEB W5 Norte, Brasília, DF, 70770-900, Brazil
| | - Francisco J L Aragão
- Embrapa Recursos Genéticos e Biotecnologia, PqEB W5 Norte, Brasília, DF, 70770-900, Brazil.
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Host-Induced Gene Silencing of Rice Blast Fungus Magnaporthe oryzae Pathogenicity Genes Mediated by the Brome Mosaic Virus. Genes (Basel) 2017; 8:genes8100241. [PMID: 28954400 PMCID: PMC5664091 DOI: 10.3390/genes8100241] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 11/17/2022] Open
Abstract
Magnaportheoryzae is a devastating plant pathogen, which has a detrimental impact on rice production worldwide. Despite its agronomical importance, some newly-emerging pathotypes often overcome race-specific disease resistance rapidly. It is thus desirable to develop a novel strategy for the long-lasting resistance of rice plants to ever-changing fungal pathogens. Brome mosaic virus (BMV)-induced RNA interference (RNAi) has emerged as a useful tool to study host-resistance genes for rice blast protection. Planta-generated silencing of targeted genes inside biotrophic pathogens can be achieved by expression of M.oryzae-derived gene fragments in the BMV-mediated gene silencing system, a technique termed host-induced gene silencing (HIGS). In this study, the effectiveness of BMV-mediated HIGS in M.oryzae was examined by targeting three predicted pathogenicity genes, MoABC1,MoMAC1 and MoPMK1. Systemic generation of fungal gene-specific small interfering RNA (siRNA) molecules induced by inoculation of BMV viral vectors inhibited disease development and reduced the transcription of targeted fungal genes after subsequent M.oryzae inoculation. Combined introduction of fungal gene sequences in sense and antisense orientation mediated by the BMV silencing vectors significantly enhanced the efficiency of this host-generated trans-specific RNAi, implying that these fungal genes played crucial roles in pathogenicity. Collectively, our results indicated that BMV-HIGS system was a great strategy for protecting host plants against the invasion of pathogenic fungi.
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Effects of DCK knockdown on proliferation, apoptosis and tumorigenicity in vivo of cervical cancer HeLa cells. Cancer Gene Ther 2017; 24:367-372. [PMID: 28820179 DOI: 10.1038/cgt.2017.31] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/27/2017] [Accepted: 06/06/2017] [Indexed: 01/25/2023]
Abstract
The present study explored the effect that deoxycytidine kinase (DCK) knockdown had on proliferation, apoptosis and tumorigenicity in vivo of cervical cancer HeLa cells. Human cervical cancer HeLa cells that had received no prior treatment were selected from the HeLa group. The HeLa-negative control (NC) group consisted of cells that had undergone an empty vector treatment, and finally the HeLa-short hairpin RNA (shRNA) group included cells that were treated by means of shRNA-DCK expression. DCK expressions were evaluated by quantitative real-time polymerase chain reaction in addition to western blotting assays. Cell proliferation was estimated using the Cell Counting Kit-8 (CCK-8) assay and cell cycle progression. Cell apoptosis was determined by flow cytometry. BALB/c nude mice (n=24) were selected to establish transplanted tumor models, with gross tumor volume measured every 3 days. The results in vitro were as follows: compared with the HeLa group, the HeLa-shRNA group exhibited downregulation of DCK expression and inhibition of cell proliferation at 48, 72 and 96 h. Additionally, more cells in the HeLa-shRNA group were arrested in G0/G1 stage and less in S and G2/M stages, as well as in promotion of cell apoptosis. In vivo results are as follows: when comparing the HeLa and HeLa-NC groups, the gross tumor volume of the transplanted tumor in nude mice in the HeLa-shRNA group was found to have decreased in 13, 16, 19 and 22 days. Based on these findings, our study suggests that DCK knockdown facilitates apoptosis while inhibiting proliferation and tumorigenicity in vivo of cervical cancer HeLa cells.
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Cooper B, Campbell KB. Protection Against Common Bean Rust Conferred by a Gene-Silencing Method. PHYTOPATHOLOGY 2017; 107:920-927. [PMID: 28437139 DOI: 10.1094/phyto-03-17-0095-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Rust disease of the dry bean plant, Phaseolus vulgaris, is caused by the fungus Uromyces appendiculatus. The fungus acquires its nutrients and energy from bean leaves using a specialized cell structure, the haustorium, through which it secretes effector proteins that contribute to pathogenicity by defeating the plant immune system. Candidate effectors have been identified by DNA sequencing and motif analysis, and some candidates have been observed in infected leaves by mass spectrometry. To assess their roles in pathogenicity, we have inserted small fragments of genes for five candidates into Bean pod mottle virus. Plants were infected with recombinant virus and then challenged with U. appendiculatus. Virus-infected plants expressing gene fragments for four of five candidate effectors accumulated lower amounts of rust and had dramatically less rust disease. By contrast, controls that included a fungal gene fragment for a septin protein not expressed in the haustorium died from a synergistic reaction between the virus and the fungus. The results imply that RNA generated in the plant moved across the fungal haustorium to silence effector genes important to fungal pathogenicity. This study shows that four bean rust fungal genes encode pathogenicity determinants and that the expression of fungal RNA in the plant can be an effective method for protecting bean plants from rust.
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Affiliation(s)
- Bret Cooper
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705
| | - Kimberly B Campbell
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705
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Peng WX, Ye C, Dong WT, Yang LL, Wang CQ, Wei ZA, Wu JH, Li Q, Deng J, Zhang J. MicroRNA-34a alleviates steroid-induced avascular necrosis of femoral head by targeting Tgif2 through OPG/RANK/RANKL signaling pathway. Exp Biol Med (Maywood) 2017; 242:1234-1243. [PMID: 28454497 PMCID: PMC5476337 DOI: 10.1177/1535370217703975] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 03/11/2017] [Indexed: 11/16/2022] Open
Abstract
The study aims to investigate the effect of microRNA-34a (miR-34a) targeting Tgif2 on steroid-induced avascular necrosis of femoral head (SANFH) by regulating OPG/RANK/RANKL signaling pathway. SD rats were divided into normal control and model (RNAKL rat models) groups. The model group was further assigned into model control, negative control, miR-34a mimics and miR-34a inhibitors groups. QRT-PCR was applied to detect miR-34a, Tgif2, OPG, RANK and RNAKL mRNA expressions. Femoral head tissues were collected for Micro-CT scanning and HE staining. QRT-PCR and Western blotting were used to detect expressions of miR-34a, Tgif2, OPG, RANK, RANKL and Runx2, OPN and OC in bone tissues. Dual-luciferase reporter gene assay was used to testify the target relationship between miR-34a and Tgif2. Compared with the normal control group, the model group showed increased Tgif2, RANK and RANKL mRNA expressions, but decreased miR-34a and OPG mRNA expressions. Tgif2 mRNA expression was negatively correlated with miR-34a and OPG mRNA expressions. Micro-CT showed cystic degeneration of femoral head, with decreased bone volume/total volume (BV/TV), bone surface area/bone volume and trabecular number in the model control group compared with the normal control group. Compared with the model control group, the miR-34a mimics group showed increased BV/TV and trabecular thickness and Runx2, OPN and OC expressions, while the parameters decreased in the miR-34a inhibitors group. Compared with the normal control group, the other groups showed increased Tgif2, RANK and RANKL expressions but decreased miR-34a and OPG expressions. Compared with the model control group, Tgif2, RANK and RANKL expressions decreased and miR-34a and OPG expressions increased in the miR-34a mimics group, while the miR-34a inhibitors group had a reverse trend in contrast to the miR-34a mimics group. Tgif2 is a target gene of miR-34a. In conclusion, miR-34a can alleviate SANFH through targeting Tgif2 and further regulating OPG/RANK/RANKL signaling pathway. Impact statement miR-34a can alleviate SANFH through targeting Tgif2 and further regulating OPG/RANK/RANKL signaling pathway, which can be used as a new theoretical basis for SANFH treatment.
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Affiliation(s)
- Wu-Xun Peng
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Chuan Ye
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Wen-Tao Dong
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Lei-Luo Yang
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Chun-Qing Wang
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Ze-An Wei
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Jian-Hua Wu
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Qing Li
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Jin Deng
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
| | - Jian Zhang
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, GuiYang 550004, P.R. China
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Faustinelli PC, Palencia ER, Sobolev VS, Horn BW, Sheppard HT, Lamb MC, Wang XM, Scheffler BE, Martinez Castillo J, Arias RS. Study of the genetic diversity of the aflatoxin biosynthesis cluster in Aspergillus section Flavi using insertion/deletion markers in peanut seeds from Georgia, USA. Mycologia 2017; 109:200-209. [PMID: 28506119 DOI: 10.1080/00275514.2017.1307095] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aflatoxins are among the most powerful carcinogens in nature. The major aflatoxin-producing fungi are Aspergillus flavus and A. parasiticus. Numerous crops, including peanut, are susceptible to aflatoxin contamination by these fungi. There has been an increased use of RNA interference (RNAi) technology to control phytopathogenic fungi in recent years. In order to develop molecular tools targeting specific genes of these fungi for the control of aflatoxins, it is necessary to obtain their genome sequences. Although high-throughput sequencing is readily available, it is still impractical to sequence the genome of every isolate. Thus, in this work, the authors proposed a workflow that allowed prescreening of 238 Aspergillus section Flavi isolates from peanut seeds from Georgia, USA. The aflatoxin biosynthesis cluster (ABC) of the isolates was fingerprinted at 25 InDel (insertion/deletion) loci using capillary electrophoresis. All isolates were tested for aflatoxins using ultra-high-performance liquid chromatography. The neighbor-joining, three-dimension (3D) principal coordinate, and Structure analyses revealed that the Aspergillus isolates sampled consisted of three main groups determined by their capability to produce aflatoxins. Group I comprised 10 non-aflatoxigenic A. flavus; Group II included A. parasiticus; and Group III included mostly aflatoxigenic A. flavus and the three non-aflatoxigenic A. caelatus. Whole genomes of 10 representative isolates from different groups were sequenced. Although InDels in Aspergillus have been used by other research groups, this is the first time that the cluster analysis resulting from fingerprinting was followed by whole-genome sequencing of representative isolates. In our study, cluster analysis of ABC sequences validated the results obtained with fingerprinting. This shows that InDels used here can predict similarities at the genome level. Our results also revealed a relationship between groups and their capability to produce aflatoxins. The database generated of Aspergillus spp. can be used to select target genes and assess the effectiveness of RNAi technology to reduce aflatoxin contamination in peanut.
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Affiliation(s)
- Paola C Faustinelli
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Edwin R Palencia
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Victor S Sobolev
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Bruce W Horn
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Hank T Sheppard
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Marshall C Lamb
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Xinye M Wang
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
| | - Brian E Scheffler
- b Genomics and Bioinformatics Research Unit, Agricultural Research Service , United States Department of Agriculture , 141 Experiment Station Road, Stoneville , Mississippi 38776
| | - Jaime Martinez Castillo
- c Centro de Investigación Científica de Yucatán , A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida , Yucatán 97200 , México
| | - Renée S Arias
- a National Peanut Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1011 Forrester Drive S.E., Dawson , Georgia 39842-0509
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50
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Power IL, Dang PM, Sobolev VS, Orner VA, Powell JL, Lamb MC, Arias RS. Characterization of small RNA populations in non-transgenic and aflatoxin-reducing-transformed peanut. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 257:106-125. [PMID: 28224915 DOI: 10.1016/j.plantsci.2016.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/01/2016] [Accepted: 12/29/2016] [Indexed: 06/06/2023]
Abstract
Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was to determine the putative involvement of the small RNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins.
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Affiliation(s)
- Imana L Power
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA.
| | - Phat M Dang
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
| | - Victor S Sobolev
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
| | - Valerie A Orner
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
| | - Joseph L Powell
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
| | - Marshall C Lamb
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
| | - Renee S Arias
- United States Department of Agriculture, Agricultural Research Service, National Peanut Research Laboratory (NPRL), 1011 Forrester Dr. S. E., Dawson, GA 39842, USA
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