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Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea
Chickpea (Cicer arietinum L.) is an important cool season food legume, however, its production is severely constrained by the foliar disease Ascochyta blight caused by the fungus Ascochyta rabiei (syn. Phoma rabiei). Several disease management options have been developed to control the pathogen, inc...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546118/ https://www.ncbi.nlm.nih.gov/pubmed/31191572 http://dx.doi.org/10.3389/fpls.2019.00644 |
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author | Zhou, Ziwei Bar, Ido Sambasivam, Prabhakaran Thanjavur Ford, Rebecca |
author_facet | Zhou, Ziwei Bar, Ido Sambasivam, Prabhakaran Thanjavur Ford, Rebecca |
author_sort | Zhou, Ziwei |
collection | PubMed |
description | Chickpea (Cicer arietinum L.) is an important cool season food legume, however, its production is severely constrained by the foliar disease Ascochyta blight caused by the fungus Ascochyta rabiei (syn. Phoma rabiei). Several disease management options have been developed to control the pathogen, including breeding for host plant resistance. However, the pathogen population is evolving to produce more aggressive isolates. For host resistance to be effective, the plant must quickly recognize the pathogen and instigate initial defense mechanisms, optimally at the point of contact. Given that the most resistant host genotypes display rapid pathogen recognition and response, the approach taken was to assess the type, speed and pattern of recognition via Resistance Gene Analog (RGA) transcription among resistant and susceptible cultivated chickpea varieties. RGAs are key factors in the recognition of plant pathogens and the signaling of inducible defenses. In this study, a suite of RGA loci were chosen for further investigation from both published literature and from newly mined homologous sequences within the National Center for Biotechnology Information (NCBI) database. Following their validation in the chickpea genome, 10 target RGAs were selected for differential expression analysis in response to A. rabiei infection. This was performed in a set of four chickpea varieties including two resistant cultivars (ICC3996 and PBA Seamer), one moderately resistant cultivar (PBA HatTrick) and one susceptible cultivar (Kyabra). Gene expression at each RGA locus was assessed via qPCR at 2, 6, and 24 h after A. rabiei inoculation with a previously characterized highly aggressive isolate. As a result, all loci were differentially transcribed in response to pathogen infection in at least one genotype and at least one time point after inoculation. Among these, the differential expression of four RGAs was significant and consistently increased in the most resistant genotype ICC3996 immediately following inoculation, when spore germination began and ahead of penetration into the plant’s epidermal tissues. Further in silico analyses indicated that the differentially transcribed RGAs function through ADP-binding within the pathogen recognition pathway. These represent clear targets for future functional validation and potential for selective resistance breeding for introgression into elite cultivars. |
format | Online Article Text |
id | pubmed-6546118 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-65461182019-06-12 Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea Zhou, Ziwei Bar, Ido Sambasivam, Prabhakaran Thanjavur Ford, Rebecca Front Plant Sci Plant Science Chickpea (Cicer arietinum L.) is an important cool season food legume, however, its production is severely constrained by the foliar disease Ascochyta blight caused by the fungus Ascochyta rabiei (syn. Phoma rabiei). Several disease management options have been developed to control the pathogen, including breeding for host plant resistance. However, the pathogen population is evolving to produce more aggressive isolates. For host resistance to be effective, the plant must quickly recognize the pathogen and instigate initial defense mechanisms, optimally at the point of contact. Given that the most resistant host genotypes display rapid pathogen recognition and response, the approach taken was to assess the type, speed and pattern of recognition via Resistance Gene Analog (RGA) transcription among resistant and susceptible cultivated chickpea varieties. RGAs are key factors in the recognition of plant pathogens and the signaling of inducible defenses. In this study, a suite of RGA loci were chosen for further investigation from both published literature and from newly mined homologous sequences within the National Center for Biotechnology Information (NCBI) database. Following their validation in the chickpea genome, 10 target RGAs were selected for differential expression analysis in response to A. rabiei infection. This was performed in a set of four chickpea varieties including two resistant cultivars (ICC3996 and PBA Seamer), one moderately resistant cultivar (PBA HatTrick) and one susceptible cultivar (Kyabra). Gene expression at each RGA locus was assessed via qPCR at 2, 6, and 24 h after A. rabiei inoculation with a previously characterized highly aggressive isolate. As a result, all loci were differentially transcribed in response to pathogen infection in at least one genotype and at least one time point after inoculation. Among these, the differential expression of four RGAs was significant and consistently increased in the most resistant genotype ICC3996 immediately following inoculation, when spore germination began and ahead of penetration into the plant’s epidermal tissues. Further in silico analyses indicated that the differentially transcribed RGAs function through ADP-binding within the pathogen recognition pathway. These represent clear targets for future functional validation and potential for selective resistance breeding for introgression into elite cultivars. Frontiers Media S.A. 2019-05-17 /pmc/articles/PMC6546118/ /pubmed/31191572 http://dx.doi.org/10.3389/fpls.2019.00644 Text en Copyright © 2019 Zhou, Bar, Sambasivam and Ford. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Plant Science Zhou, Ziwei Bar, Ido Sambasivam, Prabhakaran Thanjavur Ford, Rebecca Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title | Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title_full | Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title_fullStr | Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title_full_unstemmed | Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title_short | Determination of the Key Resistance Gene Analogs Involved in Ascochyta rabiei Recognition in Chickpea |
title_sort | determination of the key resistance gene analogs involved in ascochyta rabiei recognition in chickpea |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546118/ https://www.ncbi.nlm.nih.gov/pubmed/31191572 http://dx.doi.org/10.3389/fpls.2019.00644 |
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