Reduced Virulence of an Introduced Forest Pathogen over 50 Years
Pathogen incursions are a major impediment for global forest health. How pathogens and forest trees coexist over time, without pathogens simply killing their long-lived hosts, is a critical but unanswered question. The Dothistroma Needle Blight pathogen <i>Dothistroma septosporum</i> was...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-10-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/7/10/420 |
| _version_ | 1818555451786133504 |
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| author | Rosie E. Bradshaw Shannon Ormond Pierre-Yves Dupont Pranav Chettri I. Kutay Ozturk Rebecca L. McDougal Lindsay S. Bulman Murray P. Cox |
| author_facet | Rosie E. Bradshaw Shannon Ormond Pierre-Yves Dupont Pranav Chettri I. Kutay Ozturk Rebecca L. McDougal Lindsay S. Bulman Murray P. Cox |
| author_sort | Rosie E. Bradshaw |
| collection | DOAJ |
| description | Pathogen incursions are a major impediment for global forest health. How pathogens and forest trees coexist over time, without pathogens simply killing their long-lived hosts, is a critical but unanswered question. The Dothistroma Needle Blight pathogen <i>Dothistroma septosporum</i> was introduced into New Zealand in the 1960s and remains a low-diversity, asexual population, providing a unique opportunity to analyze the evolution of a forest pathogen. Isolates of <i>D. septosporum</i> collected from commercial pine forests over 50 years were compared at whole-genome and phenotype levels. Limited genome diversity and increased diversification among recent isolates support the premise of a single introduction event. Isolates from the 1960s show significantly elevated virulence against <i>Pinus radiata</i> seedlings and produce higher levels of the virulence factor dothistromin compared to isolates collected in the 1990s and 2000s. However, later isolates have no increased tolerance to copper, used in fungicide treatments of infested forests and traditionally assumed to be a strong selection pressure. The isolated New Zealand population of this forest pathogen therefore appears to have become less virulent over time, likely in part to maintain the viability of its long-lived host. This finding has broad implications for forest health and highlights the benefits of long-term pathogen surveys. |
| first_indexed | 2024-12-12T09:53:38Z |
| format | Article |
| id | doaj.art-24af3fafee004d0180a1af2eca64bfa1 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-12-12T09:53:38Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj.art-24af3fafee004d0180a1af2eca64bfa12022-12-22T00:28:12ZengMDPI AGMicroorganisms2076-26072019-10-0171042010.3390/microorganisms7100420microorganisms7100420Reduced Virulence of an Introduced Forest Pathogen over 50 YearsRosie E. Bradshaw0Shannon Ormond1Pierre-Yves Dupont2Pranav Chettri3I. Kutay Ozturk4Rebecca L. McDougal5Lindsay S. Bulman6Murray P. Cox7School of Fundamental Sciences and Bio-Protection Research Centre, Massey University, Palmerston North 4410, New ZealandSchool of Fundamental Sciences and Bio-Protection Research Centre, Massey University, Palmerston North 4410, New ZealandInstitute of Environmental Science and Research, Christchurch 8041, New ZealandAgResearch, Palmerston North 4410, New ZealandSchool of Fundamental Sciences and Bio-Protection Research Centre, Massey University, Palmerston North 4410, New ZealandScion, NZ Forest Research Institute Ltd, Rotorua 3010, New ZealandScion, NZ Forest Research Institute Ltd, Rotorua 3010, New ZealandSchool of Fundamental Sciences and Bio-Protection Research Centre, Massey University, Palmerston North 4410, New ZealandPathogen incursions are a major impediment for global forest health. How pathogens and forest trees coexist over time, without pathogens simply killing their long-lived hosts, is a critical but unanswered question. The Dothistroma Needle Blight pathogen <i>Dothistroma septosporum</i> was introduced into New Zealand in the 1960s and remains a low-diversity, asexual population, providing a unique opportunity to analyze the evolution of a forest pathogen. Isolates of <i>D. septosporum</i> collected from commercial pine forests over 50 years were compared at whole-genome and phenotype levels. Limited genome diversity and increased diversification among recent isolates support the premise of a single introduction event. Isolates from the 1960s show significantly elevated virulence against <i>Pinus radiata</i> seedlings and produce higher levels of the virulence factor dothistromin compared to isolates collected in the 1990s and 2000s. However, later isolates have no increased tolerance to copper, used in fungicide treatments of infested forests and traditionally assumed to be a strong selection pressure. The isolated New Zealand population of this forest pathogen therefore appears to have become less virulent over time, likely in part to maintain the viability of its long-lived host. This finding has broad implications for forest health and highlights the benefits of long-term pathogen surveys.https://www.mdpi.com/2076-2607/7/10/420dothistroma needle blightforest pathogenclonal populationvirulencemycotoxin |
| spellingShingle | Rosie E. Bradshaw Shannon Ormond Pierre-Yves Dupont Pranav Chettri I. Kutay Ozturk Rebecca L. McDougal Lindsay S. Bulman Murray P. Cox Reduced Virulence of an Introduced Forest Pathogen over 50 Years Microorganisms dothistroma needle blight forest pathogen clonal population virulence mycotoxin |
| title | Reduced Virulence of an Introduced Forest Pathogen over 50 Years |
| title_full | Reduced Virulence of an Introduced Forest Pathogen over 50 Years |
| title_fullStr | Reduced Virulence of an Introduced Forest Pathogen over 50 Years |
| title_full_unstemmed | Reduced Virulence of an Introduced Forest Pathogen over 50 Years |
| title_short | Reduced Virulence of an Introduced Forest Pathogen over 50 Years |
| title_sort | reduced virulence of an introduced forest pathogen over 50 years |
| topic | dothistroma needle blight forest pathogen clonal population virulence mycotoxin |
| url | https://www.mdpi.com/2076-2607/7/10/420 |
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