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Debler JW, Henares BM. Targeted Disruption of Scytalone Dehydratase Gene Using Agrobacterium tumefaciens-Mediated Transformation Leads to Altered Melanin Production in Ascochyta lentis. J Fungi (Basel) 2020; 6:E314. [PMID: 33255939 DOI: 10.3390/jof6040314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 11/17/2022] Open
Abstract
Sustainable crop production is constantly challenged by the rapid evolution of fungal pathogens equipped with an array of host infection strategies and survival mechanisms. One of the devastating fungal pathogens that infect lentil is the ascomycete Ascochyta lentis which causes black spot or ascochyta blight (AB) on all above ground parts of the plant. In order to explore the mechanisms involved in the pathogenicity of A. lentis, we developed a targeted gene replacement method using Agrobacterium tumefaciens mediated transformation (ATMT) to study and characterize gene function. In this study, we investigated the role of scytalone dehydratase (SCD) in the synthesis of 1,8-dihydroxynaphthalene (DHN)-melanin in AlKewell. Two SCD genes have been identified in AlKewell, AlSCD1 and AlSCD2. Phylogenetic analysis revealed that AlSCD1 clustered with the previously characterized fungal SCDs; thus, AlSCD1 was disrupted using the targeted gene replacement vector, pTAR-hyg-SCD1. The vector was constructed in a single step process using Gibson Assembly, which facilitated an easy and seamless assembly of multiple inserts. The resulting AlKewell scd1::hyg transformants appeared light brown/brownish-pink in contrast to the dark brown pycnidia of the WT strain and ectopic transformant, indicating an altered DHN-melanin production. Disruption of AlSCD1 gene did not result in a change in the virulence profile of AlKewell towards susceptible and resistant lentil varieties. This is the first report of a targeted gene manipulation in A. lentis which serves as a foundation for the functional gene characterization to provide a better understanding of molecular mechanisms involved in pathogen diversity and host specificity.
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Khorramdelazad M, Bar I, Whatmore P, Smetham G, Bhaaskaria V, Yang Y, Bai SH, Mantri N, Zhou Y, Ford R. Transcriptome profiling of lentil (Lens culinaris) through the first 24 hours of Ascochyta lentis infection reveals key defence response genes. BMC Genomics 2018; 19:108. [PMID: 29385986 PMCID: PMC5793396 DOI: 10.1186/s12864-018-4488-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 01/17/2018] [Indexed: 09/14/2023] Open
Abstract
Background Ascochyta blight, caused by the fungus Ascochyta lentis, is one of the most destructive lentil diseases worldwide, resulting in over $16 million AUD annual loss in Australia alone. The use of resistant cultivars is currently considered the most effective and environmentally sustainable strategy to control this disease. However, little is known about the genes and molecular mechanisms underlying lentil resistance against A. lentis. Results To uncover the genetic basis of lentil resistance to A. lentis, differentially expressed genes were profiled in lentil plants during the early stages of A. lentis infection. The resistant ‘ILL7537’ and susceptible ‘ILL6002’ lentil genotypes were examined at 2, 6, and 24 h post inoculation utilising high throughput RNA-Sequencing. Genotype and time-dependent differential expression analysis identified genes which play key roles in several functions of the defence response: fungal elicitors recognition and early signalling; structural response; biochemical response; transcription regulators; hypersensitive reaction and cell death; and systemic acquired resistance. Overall, the resistant genotype displayed an earlier and faster detection and signalling response to the A. lentis infection and demonstrated higher expression levels of structural defence-related genes. Conclusions This study presents a first-time defence-related transcriptome of lentil to A. lentis, including a comprehensive characterisation of the molecular mechanism through which defence against A. lentis is induced in the resistant lentil genotype. Electronic supplementary material The online version of this article (10.1186/s12864-018-4488-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mahsa Khorramdelazad
- Glycomics institute, School of Sciences, Griffith University, 58 Parklands Dr., Southport, Gold Coast, 4215, QLD, Australia
| | - Ido Bar
- Environmental Futures Research Institute, School of Natural Sciences, Griffith University, 170 Kessels Rd., Nathan, 4111, QLD, Australia.
| | - Paul Whatmore
- Environmental Futures Research Institute, School of Natural Sciences, Griffith University, 170 Kessels Rd., Nathan, 4111, QLD, Australia.,Genecology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore DC, 4558, Queensland, Australia
| | - Gabrielle Smetham
- Fish Nutrition and Feed Safety, the National Institute of Nutrition and Seafood Research (NIFES), Strandgaten 229, Bergen, 5002, Norway
| | - Vijay Bhaaskaria
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 142 University St., Parkville, 3053, VIC, Australia
| | - Yuedong Yang
- Pangenomics Group, School of Sciences, RMIT University, Bundoora, 3083, VIC, Australia
| | - Shahla Hosseini Bai
- Glycomics institute, School of Sciences, Griffith University, 58 Parklands Dr., Southport, Gold Coast, 4215, QLD, Australia
| | - Nitin Mantri
- Environmental Futures Research Institute, School of Natural Sciences, Griffith University, 170 Kessels Rd., Nathan, 4111, QLD, Australia.,Genecology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore DC, 4558, Queensland, Australia
| | - Yaoqi Zhou
- Pangenomics Group, School of Sciences, RMIT University, Bundoora, 3083, VIC, Australia
| | - Rebecca Ford
- Glycomics institute, School of Sciences, Griffith University, 58 Parklands Dr., Southport, Gold Coast, 4215, QLD, Australia
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Dadu RHR, Ford R, Sambasivam P, Gupta D. A Novel Lens orientalis Resistance Source to the Recently Evolved Highly Aggressive Australian Ascochyta lentis Isolates. Front Plant Sci 2017; 8:1038. [PMID: 28659965 PMCID: PMC5470093 DOI: 10.3389/fpls.2017.01038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/30/2017] [Indexed: 05/08/2023]
Abstract
Substantial yield losses and poor seed quality are frequently associated with Ascochyta blight infection of lentil caused by Ascochyta lentis. Recently reported changes in aggressiveness of A. lentis have led to decreased resistance within cultivars, such as Northfield and Nipper in Australia. Furthermore, the narrow genetic base of the current breeding program remains a risk for further selective pathogen evolution to overcome other currently used resistances. Therefore, incorporation of potentially novel and diverse resistance genes into the advanced lines will aid to improve cultivar stability. To identify these, 30 genotypes sourced from five wild species (Lens orientalis, L. odomensis, L. ervoides, L. nigricans and L. lamottei), including eight previously reported resistance sources, were screened for disease reaction to two recently isolated and highly aggressive isolates. Subsequently, two L. orientalis accessions were found highly resistant and a further six L. nigricans, one L. odomensis, one L. ervoides, one L. lamottei, and one L. orientalis accessions were moderately resistant. Several of these were more resistant than the currently deployed resistance source, ILL 7537. Furthermore, L. orientalis accession ILWL 180 was consistently resistant against other highly aggressive isolates recovered from diverse geographical lentil growing regions and host genotypes, suggesting stability and potential for future use of this accession in the Australian lentil breeding program.
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Affiliation(s)
- Rama H. R. Dadu
- Faculty of Veterinary and Agricultural Sciences, University of MelbourneDookie, VIC, Australia
- *Correspondence: Rama H. R. Dadu
| | - Rebecca Ford
- Environmental Futures Research Institute, School of Natural Sciences, Griffith UniversityNathan, QLD, Australia
| | - Prabhakaran Sambasivam
- Environmental Futures Research Institute, School of Natural Sciences, Griffith UniversityNathan, QLD, Australia
| | - Dorin Gupta
- Faculty of Veterinary and Agricultural Sciences, University of MelbourneDookie, VIC, Australia
- Dorin Gupta
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